Earth Science Informatics

https://doi.org/10.1007/s12145-018-0343-9

REVIEW ARTICLE

Review of smartphone applications for geoscience: current status,

limitations, and future perspectives
Sangho Lee 1 & Jangwon Suh 2 & Yosoon Choi 3

Received: 2 July 2017 / Revised: 6 February 2018 / Accepted: 22 March 2018

# Springer-Verlag GmbH Germany, part of Springer Nature 2018

Abstract
Smartphones can be utilized in the field of geosciences for various purposes due to their multifaceted abilities that combine both
hard- and software features. The unique abilities of smartphones allow new methodologies for the collection and visualization of
data that rarely become available in traditional computing platforms. In this study, commercially available smartphone applica-
tions (apps) that have been released in geoscience (e.g., geology/soil, minerals and rocks, petroleum and gas) so far were
investigated. The apps were categorized based on the extent of smartphone feature usage into (a) basic, standard-feature apps;
(b) calculator and referencing apps; and (c) sensing and communication apps. Furthermore, each of these categories was divided
into several app groups based on specific features. Representative apps of each specific app group were selected and their
characteristics and applicability were examined. Lastly, major limitations regarding smartphone app development and imple-
mentation in geoscience and implications for future improvements were discussed.

Keywords Smartphone . Geoscience . Application . Sensor

Introduction Ever since their release, smartphones have been drawing

attention with respect to scientific uses; the scope of their
As of 2016, more than 3.9 billion people use smartphones. The applicability has rapidly expanded in recent years (Evanko
number accounts for 55% of all mobile subscriptions and is 2010). Similarly, a number of smartphone applications
anticipated to continue to grow in the future (Cerwall et al. (apps) have been developed in the realm of geosciences for
2016). Smartphones can be used for various purposes; their purposes of collecting, storing, analyzing, and visualizing var-
versatility ranges from fast processing and portability to con- ious sets of information and data. Especially, new attempts
nectivity with a number of networks to sensors allowing the that were impossible with preexisting single-platform solu-
measurement of properties of the device itself and the external tions have recently been made by utilizing the phones’ porta-
environment. Furthermore, smartphones are equipped with in- bility and sensing capability (Lee et al. 2013). As more geo-
tuitive software (S/W) distribution systems and thus have sig- science apps are expected to be released, it is required to
nificant benefits associated with small costs when applications review the smartphone apps for geoscience in terms of current
are developed to replace existing methods or tools. status, limitations and future perspectives.
This paper reviews the status and characteristics of
smartphone apps developed in geosciences, to consider the
Communicated by: H. A. Babaie
future directions of improvement. Apps for smartphones and
tablets that have been released on the Android and iOS plat-
* Yosoon Choi
energy@pknu.ac.kr
forms and are available to users are focused on in this review.
The limited focus reflects the assumption that the analysis of
1
Korea Institute of Geoscience and Mineral Resources (KIGAM), non-Android and non-iOS operating systems (OS) would
Daejeon 34132, South Korea have no practical significance, given the >99% share of the
2
Department of Energy and Mineral Resources Engineering, two OSs in the smartphone OS market (IDC 2016). The se-
Kangwon National University, Samcheok 25913, South Korea lection of relevant apps was carried out via Google Play and
3
Department of Energy Resources Engineering, Pukyong National the Apple App Store, respectively, because these are the offi-
University, Busan 48513, South Korea cial app markets for the two OSs.
 Earth Sci Inform

Some smartphone apps are often functionally similar or adopted as useful tools for acquiring geological information
identical to the software available on the desktop. This is of the area in the field.
due to the nature of the smartphone, which allows for overall The camera utility is an essential part of the smartphone
computing similar to desktop. In contrast, others that utilize because it replaces a conventional small-sized digital camera,
always-connected capacity and sensors such as accelerome- which is widely used for field surveys. A complementary
ters, magnetic fields, etc., which are generally mounted on metal-oxide-semiconductor (CMOS) sensor is generally used
smartphones, have unique functionality as being difficult or as an optical image sensor in modern smartphones. The sensor
impossible to use as desktops. Therefore, the apps reviewed in can provide high-resolution images with enough quality con-
this study were classified into several groups by considering suming low power (Gove 2014). A user can observe detailed
the functional use of smartphone. This classification can pro- geological features without using additional optical equipment
vide a glimpse of the prospect of geoscience apps that can be by using digital magnification of the camera software or by
used not only as computing devices that replace desktops but zooming into a captured image as modern flagship
also only on smartphones. smartphone cameras are able to provide photos on the micro-
The sections of this paper are as follows, depending on the scopic level without additional attachment (Graff and Wu
extent to which built-in features of smartphones are utilized: 2014), while the screen size of the has become larger in recent
(a) Section 2 explains the cases in which smartphone default years (Kim and Sundar 2016).
abilities and applications, not 3rd party developer-created Web browsers are often used to collect information from
apps, are put to use; (b) Section 3 investigates field-by-field remote websites. The recent development of a dynamic web
cases in which exclusive use is made of the smartphone com- environment provides numerous opportunities for the applica-
puting and storage capacity such as data entry, computation, tion in the geosciences to both developers and users, especial-
and analysis in particular fields or disciplines; (c) Section 4 ly for webmapping (Cayla 2014). Some websites such as the
examines apps that collect information and data using sensors British Geological Survey’s (BGS) GeoIndex (Smith 2013)
and/or utilize the data for visualization purposes, for example, and Korea Institute of Geoscience and Mineral Resources’s
mapping or augmented reality (AR); and (d) Section 5 dis- (KIGAM) MGEO (Han and Yeon 2014) provide geologic
cusses limitations and challenge-posing problems in maps on a mobile-friendly interface. These web services also
smartphone app development in geoscience and seeks viable provide their maps via standard protocol, including web map
solutions and alternatives. service (de La Beaujardiere 2006), to maximize their compat-
ibility with different application software (Guo et al. 2012).
Therefore, the data visible on the smartphone can easily be
mounted on desktop browsers or applications (Fig. 1). This
General applications using built-in software type of plugin-free, web-based visualization is also applicable
to 3D models (De Paor 2016).
As smartphone is a type of mobile computing device; In addition, a website specially developed for mobile envi-
smartphone manufacturers generally include pre-installed soft- ronments is able to provide more functionality than a conven-
ware in their devices to provide essential primary functions for tional one. Without using native Application Program
general use. Software includes text editor, photo viewer, camera Interfaces (APIs), which require a specific OS environment
software, and web browser. Many parts of plain tasks can be to run them, several World Wide Web Consortium (W3C)
handled by combinations of these utility programs with the aid standards enable developers to handle hardware sensors with-
of the multitasking capability of the smartphone, while each of in smartphones through different web browsers using com-
them can conduct a few simple tasks. mon web APIs (Popescu 2016; Langel and Waldron 2017).
For example, a smartphone can be a substitute for essential None of the geological web services adopted these technolo-
equipment including writing instruments, compass, voice re- gies, yet; however a few studies indicated the possibility of
corder, and digital camera. The combination of these features website-based smartphone utilization for geological purposes
is available within a single device through the multitasking (Sharakhov et al. 2013; Nguyen et al. 2015).
capability of smartphone platforms. Text recording can be
conducted using text editors based on different types of input
methods. A virtual keyboard or onscreen keyboard is general- Field-specific calculation, analysis,
ly used to input text by touching each virtual key; however, and logging software
other methods are also available such as tracing, handwriting,
and voice input. Especially, the recent development of speech Many applications do not use the functionalities that are avail-
recognition technology allows so-called voice dictation, able only on smartphones if wireless connectivity or physical
which enables fast text input by speaking (Smith and properties of the device are not required to fulfill the objective
Chaparro 2015). Document and photo viewers can also be of the software. In this case, the advantages of the smartphone
Earth Sci Inform

Fig. 1 Use of online geologic maps on built-in web browsers. (a) BGS GeoIndex, (b) KIGAM MGEO
 Earth Sci Inform

are the small size of the device and programmable and user- In engineering geology, relevant app development con-
adjustable OS environments. These applications generally cerns rock mass classification and slope safety factor calcula-
collect data via manual input and provide computed results tion. Representative apps include RMR Calc (Terrasolum
using a variety of mathematical functions for specific engi- 2014a), an Android-based app that calculates rock mass rating
neering purposes. Most of the geological applications belong (RMR) values for rocks based on the rock mass classification.
to this category because it does not involve complex program- For RMR value calculation, values of six factors (uniaxial
ming and developers can thus focus on the logical implemen- compressive strength of rock material; rock quality designa-
tation of their engineering knowledge. Section 3 further di- tion, RQD; spacing of discontinuities; condition of disconti-
vides the mentioned applications into specific categories such nuities; groundwater conditions; and orientation of disconti-
as engineering calculation, field survey, education and learn- nuities) are entered into the program via the user interface. The
ing, and referencing. resulting RMR values between 0 and 100 can be shared on
other devices or via email.

Engineering calculator applications Field survey applications

Applications enabling engineering-related calculations on Field survey-related applications have been developed mainly
smartphones, include a number of apps developed for pe- for geological survey, with some apps in petroleum and gas
troleum and gas engineering and engineering geology engineering (Table 2). For these apps, Android and iOS sys-
(Table 1). Of the 57 apps studied in this paper, 17 apps tems take up similar proportions; in terms of the pricing pol-
can be used only on the Android platform, 31 only on the icy, free apps outweigh paid apps. The main utilities to be
iOS platform, and 9 on either Android or iOS; iOS-only performed by geological survey apps are: sampling location
apps occupy a relatively high proportion. Moreover, the 57 selection, field survey information/data entry and control, geo-
apps consist of 24 free apps and 34 paid apps, with the logical profile preparation, soil boring logging, and stereo-
latter claiming a slightly higher proportion. graphic projection (stereonet) preparation.
A large number of apps developed in the field of petroleum For example, iGeoLog (MangoCreations 2016), an applica-
and gas engineering include mostly the ones that allow engi- tion for drawing geological cross sections, can be used to illus-
neering computations including drilling trajectory analysis, trate field observations directly in the field (Fig. 3a). Although
casing design, nozzle design, drilling cost estimation, well the software only can draw partial sections vertically, it provides
control, and petroleum fluid property calculation. A primary common textures, fossil icons, and an integrated interface en-
example is iPBORE (iPMI-RMC 2014), which allows engi- abling the quick drawing of observations. It implies the benefit
neers to analyze and simulate the stability of wells over time of a smartphone application for a specific geological purpose by
during drilling operations (Fig. 2a). It provides several func- concentrating related functionalities in a single package.
tionalities for conventional elastic wellbore stability modeling A boring log is a suitable case for this type of application
such as (a) failure analysis to evaluate the critical mudweight because it is generally documented in standard formats com-
for fracturing and collapse conditions, (b) estimation of critical posed of fixed components. Similar to other desktop boring
regions near the wellbore under a specified mudweight to log software, LogMATE (GME Systems 2014a, 2014b) and
visualize regions prone to failure, (c) calculation of the safe PersonalGeo (CZL Solutions 2016) accept user input in a
mudweight window as a function of hole inclination or azi- predefined format and exports the data for further utilization
muth, and (d) optimization for directional drilling by generat- (Figs 3b, c). Although these applications do not export orga-
ing polar charts to evaluate critical mudweights for the entire nized boring log documents, as desktop software do, they are
range of hole inclination and azimuth. This app can operate on still useful for in situ recording rather than using heavy desk-
both Android and iOS platforms. tops or laptops because of their portability.
Another example of petroleum and gas engineering apps is
Oil PVT Properties (PetroSimple 2016). This Android-based Education and learning applications
app allows mobile devices to calculate the pressure–volume–
temperature (PVT) properties of key fluids on the project sites Careful review of the purposes and utilities of the 34 mobile
(Fig. 2b). This app computes the solution gas oil ratio, forma- apps related to education and learning in the field of
tion volume factor, density, viscosity, and compressibility at geosciences has revealed that the apps can be roughly divided
the pressure range and temperature using user inputs and unit into four groups: (a) textbook; (b) lecture; (c) simulation; and
configurations. The resulting properties are plotted against the (d) game and quiz. These are, for the most part, more detailed
pressure on graphical interfaces. The results of the calcula- versions of the categorization of this study, indicated by de-
tions can be exported into word processors, or sent via email velopers on Google Play and App Store as Beducation,^
for sharing on other devices. Bbooks,^ Breferences,^ and other categories. Some of the apps
Earth Sci Inform

Table 1 Engineering calculator

applications Field Name Platform Price Remark

PE 3D Drilling A Free AbsLab 2016

PE Alpha Petroleum Engineers App A $9.99 Ahonsi 2014
PE Bean Choke Tool I $0.99 Jonathon Gatewood 2014
PE Casing Setting I $9.99 Cafm 2016a
PE CemWell I $1.99 Yasi 2013
PE Directional Calculations I $4.99 Cafm 2015a
PE Directional Drilling I $19.99 Cafm 2015b
PE Directional Survey A Free Mikhailov 2016
PE Directional Survey Calculation I Free Cafm 2016b
Methods
PE Dr DE - Drilling Toolbox A Free Pegasus Vertex Inc. 2015
PE Drill Bit Nozzle Calculator A,I Free National Oilwell Varco 2016,
2017
PE DrillCalcs™ by Drilling I Free Chevron Phillips Chemical
Specialties Company LP 2015
PE Driller’s Method I $9.99 Cafm 2015d
PE Drilling Co$t I $9.99 Cafm 2017a
PE Drilling Engineering A,I Free Pertamina Drilling UTC 2014,
2017
PE Drilling Hydraulics I $14.99 Cafm 2014
PE Drilling Units I Free Cafm 2017b
PE Dynamic Volumetric Method I $9.99 Cafm 2015e
PE ECD Calculator A Free Oilfield Apps 2015a
PE FracAppz App I Free FracAppz Studios LLC, 2015
PE iPBORE A,I Free iPMI-RMC 2012, 2014
PE Kick Tolerance I $14.99 Cafm 2016f
PE Leak-Off Test I $9.99 Cafm 2016c
PE Mud & Cement Calculator (KOC) A $6.43 Saify Solutions 2014a
PE Mud Balance A Free Oilfield Apps 2015b
PE Oil Field Handy Calc A,I $8.66/$8.99 Saify Solutions 2014b,c
PE Oil PVT Properties A Free PetroSimple 2016
PE OilField & Drilling Mud Lab I $0.99 Uakanov 2015b
PE OilField Annular Volume Pro I $0.99 Uakanov 2014a
PE Oilfield Assistant - Formulas A $5.99 Synergetic S.A.S -Col 2016
PE Oilfield Calculator - Pump I Free Theta Oilfield Services 2015
Slippage
PE OilField Coiled Tubing Data I $0.99 Uakanov 2015a
PE OilField ECD Pro I $0.99 Uakanov 2014b
PE OilField Engineer I $3.99 Uakanov 2016b
PE Oilfield Essentials A,I $13.46/$14.29 Gaber 2014, 2015
PE OilField FIT & Leak-Off Test I $0.99 Uakanov 2014c
PE OilField Formulas for iHandy I $1.99 Uakanov 2016a
Calc.
PE OilField iHandbook I $1.99 Uakanov 2014d
PE OilfieldUnitConverter I Free Azorey 2013
PE PetroCalc A Free Persad 2017
PE PetroLeum Engineer I Free Salih 2016
PE Petroleum Measurement Calc A $3.17 mule-software.com 2012
PE Petroleum Volume Correction Pr A $3.99 Maldo 2012
PE PETROLEUM VOLUME I $14.99 MAAI 2010
CORRECTION TABLES
PE Phrikolat HDD Basics A,I Free Knopf 2016a,b
 Earth Sci Inform

Table 1 (continued)
Field Name Platform Price Remark

PE Pressure Calculator A Free Oilfield Apps 2015c

PE Quick Calc Hydraulics A,I Free Schlumberger Technology
Corporation 2012, 2014
PE ResToolbox Pro A,I $2.15/$3.29 MobileReservoir 2015a,b
PE SmartDriller A Free VenSoft 2017
PE Strokes Calculator A Free Oilfield Apps 2015d
PE Ton Miles Calculator I $19.99 Cafm 2016d
PE Ton Miles for Round Trip I $4.99 Cafm 2016e
PE Volumetric Method I $9.99 Cafm 2016g
PE Wait and Weight Method I $9.99 Cafm 2015c
PE WellHandbook A,I Free Ofsapps 2012a,b
EG RMR Calc A $1.92 Terrasolum 2014a
EG Simple Slope A Free Terrasolum 2014b

were found to fall in two or more categories (e.g., lecture and is exclusive of lectures in video format. The majority of the
game); however, they were included into a single category, apps reviewed in this study were confirmed to be free and
respectively, based on their major function. available on the Android OS system. Except for the e-book
The text apps are e-books, which contain text and illustra- format in which they are offered, the text apps have no other
tions of traditional books or web-based documents. These apps particular features. Based on the discipline, they are available in
differentiate themselves from lecture apps in that their material fields such as engineering geology (Appstube.in 2017a;

Fig. 2 Representative
smartphone applications for
oilfield calculations and analysis.
(a) iPBORE, (b) Oil PVT
Properties
Earth Sci Inform

Table 2 Smartphone apps for

field surveys Field Name Platform Price Remark

GS aFieldWork A Free Geus 2015

GS Geological Field Notes I $4.99 Zhang 2017
GS geoMapper - Surface Mapping for Field I Free rapidBizApps 2015
Geologists
GS iGeoLog I $1.99 MangoCreations 2016
GS Kapalo A Free Geological survey of Finland 2016
GS LogMATE A,I Free GME Systems 2014a,b
GS PersonalGeo A Free CZL Solutions 2016
GS StereoNet I $0.99 Tectonic Engineering Consultants
Co. Ltd. 2012
GS Stereonet Mobile I Free Allmendinger 2017
GS Strataledge A Free Endeeper 2017

Engineering Wale Baba 2016), principles of geology Fundamentals of folds and faults (Tasa Graphic Arts Inc.
(Appstube.in 2017b; Komakuro 2017a), and geological history 2013a); (b) Major issues in geosciences for elementary and
(Komakuro 2017b). middle school students (Sprout Labs LLC 2015); (c)
The lecture apps aim at learning by users. They function as Geological time table and period-specific characteristics
conveyor of knowledge using a variety of materials including (glossary; Tasa Graphic Arts Inc. 2013b; Tengel 2016); (d)
textbooks, glossaries, photos, animations, and videos. The Interactive visualization app for hands-on preparation of soil
apps sometimes come with simple quiz questions for review profiles from 3D soil strata (RootMotion 2013); (e)
purposes. Price-wise, most apps range between $0 (free) to $3 Description of plate tectonics and interactive visualization
and offering learning materials in various forms. So far, apps apps allowing the dynamic representation on a 3D model
representing vast areas have been released such as geology, globe, disintegration of Pangaea, and location of the conti-
volcanology, minerals and rocks, engineering geology, and nents for the past 0.2 billion years (Tasa Graphic Arts Inc.
mining engineering. Specifically, they include: (a) 2015); (f) Glossary on Hawaiian volcanic sites (Fire Work

Fig. 3 Representative smartphone applications for field investigations. (a) iGeoLog, (b) LogMATE, (c) PersonalGeo
 Earth Sci Inform

Media 2015); (g) Understanding and identification of minerals conveying expert knowledge through lectures and simula-
and rocks (Davis 2012); (h) Apps that visualize and identify in tions; (b) require no previous exposure to the discipline; and
3D format the 3D crystal structure and configuration of min- (c) are easy to understand and interestingly put together
erals (Apopei 2016); (i) Apps that observe various optical (games and quizzes), so that children and laypeople can famil-
properties (e.g., refraction, birefringence, and pleochroism) iarize themselves with the world of geosciences. Some of
of thin rock section samples examined via virtual polarizing these apps, however, offer learning-related features including
microscopy (Fig. 4a, Open University 2010); and (j) Soil dy- games and quizzes and documented background information
namics lecture apps that offer textbooks and glossary on video and descriptions of related phenomena. Ranging in price be-
(Engineering Apps 2017). tween $0 (free) and $5, the apps address a variety of subjects
The simulation apps are used in the geosciences to (a) such as geology, minerals, petroleum and gas, and volcanoes.
analyze and solve problems regarding a question or scientific Specific examples are: (a) Quiz apps that simply evalu-
phenomenon by creating a simplified version of a model and ate geological knowledge (Shoaib 2016); (b) Apps that
(b) use the model to allow the entry of various factors/ interactively visualize the structure of the Earth and
variables and establishment of conditions/parameters and op- gravity-induced phenomena (Tinybop Inc. 2016); (c)
tions for understanding the properties concerned by simula- Card-game apps that investigate the physical properties
tion. The simulations then indicate or graphically/visually rep- of minerals (Soaring Emu 2016); (d) Game apps that
resent the calculated values (results) for the particular question utilize geological knowledge to increase the petroleum
under investigation. All of the simulation apps reviewed in resource development project profitability (Geonova
this study were iPhone apps. Most of these iPhone apps ad- 2015); (e) Apps dedicated to children that offer various
dress drilling and other limited topics in petroleum and gas photos, videos, and puzzle-games about volcanoes
engineering and are paid apps, with a price ranging between ( E n cy cl op ae di a B r i t a nn i c a In c. 2 01 3) ; a nd ( f)
$10 and $50. The majority of the apps offer graphic interfaces Geotourism apps designed to facilitate the users’ under-
and varieties of visualization features to live up to the expec- standing of rocks that were used to build the
tations when the entry of variables and establishment of Barcelonan architecture (Universitat de Barcelona 2016).
conditions/parameters and options are required for the simu-
lation processes. In terms of detailed features, the apps include Reference applications
the (a) Leak Off Test Simulator (Fig. 4b, Cafm 2014) and Well
Control Simulator (Cafm 2015f, 2016a), which are usable in Eighty-two mobile applications in form of various reference
well-control phases; and (b) Drilling Simulator (Cafm 2016b, materials dealing with geosciences were reviewed in terms of
c) and MPD Simulator (Cafm 2017a, b, c) which can be used their purpose and utility. The results indicate that the apps can
during the course of drilling. be roughly classified into four categories, namely dictionary,
With respect to game and quiz apps, selections and catego- handbook, map, and tour guide. These four categories repre-
rization were made of those materials that (a) do not aim at sent the recategorization of app characteristics by the authors

Fig. 4 Representative smartphone applications for learning, education, and field references. (a) Virtual Microscope (Open University 2010), (b) Leak Off
Test Simulator (Cafm 2014), (c) Smart Geology – Mineral Guide (Chakraborty 2016b), (d) Rockd (UW Macrostrat 2017a, b)
Earth Sci Inform

of this paper based on their discussion and judgment of the and (e) can identify particular minerals based on given prop-
applications that were originally indicated as^ education,B^ erties or conditions (Adventuroo Apps 2013; Disigma
books,^^ references,B^ productivity, BBbusiness,^ Publications 2017; Yakobo 2017).
Bweather,^^ travel,^ and other categories on Google Play The petroleum and gas dictionaries include glossaries for
and the Apple Store by their respective developers. the terminology used in the industry including wells and pro-
Based on headings, the dictionary apps refer to glossaries, duction sites. This study identified dictionary apps that offer
which compile various pieces of information, arrange them in text-based definitions and descriptions of terminology includ-
proper sequences, and provide explanations for each one of ing apps that (a) list only very basic features (Putranto 2016a,
them or descriptions of technical terms or jargon. The apps are 2016b; Paprika Studio 2016; Schlumberger Technology
formatted similarly to conventional web-based dictionaries Corporation 2016); and (b) are glossaries offering
available on the Internet; in fact, some of the apps require bookmarking or custom content features (Bazilikka 2014;
access to the Internet to allow a search and view results. The Akdas 2016; Dener 2017b). Additionally, some apps have
basic feature offered universally by all of the dictionary apps is been released that offer texts and sufficient photos (Sand
Bsearch and view^ using character/letter-based words (or no- Apps Inc. 2016a, b, c).
menclature). Additionally, some apps include images for the Handbook applications summarize the frequently used
terminology, depending on the subject matter being addressed information/data and complicated contents in certain specific
in the dictionaries. Extra features can be included such as areas (geology, minerals and rocks, petroleum and gas) and
automatic search-history saving and tracking (words organize them into tables, equations, official statistics, and
searched), bookmarking to allow favorites, custom contents diagrams and present them to users for easy access at job sites.
to allow the user to add terminology and definition, word Such applications sometimes also offer guidelines or useful
quizzes; and features that allow users to share search words tips. The foregoing characteristics distinguish handbook apps
and information obtained. The apps range in price from $0 from dictionary apps (mostly aiming at simple terminology
(free) to $10. The categorization of the geoscience dictionary explanation) and textbook apps (aiming to convey compre-
apps by subject shows results for geology, minerals and rocks, hensive information on certain disciplines through a variety
and oil and gas. of contents). No free apps were identified among those inves-
Basically, the most common form of geological dictionar- tigated in this study; instead, the apps range in price from
ies offers text-based information about the terminology in- $1–$5. With the majority of the handbook apps addressing
cluding images or illustrations. Based on the feature, there the oil and gas industry, the lack of free offers is believed to
are various applications that (a) offer only very basic dictio- be due to vast numerical computations, programming, and
nary features (Apps Artist 2016; Techhuw 2016; Best Mobile control work required during development and production
Dictionary 2017; IM7 2017); (b) have added Bshare^ features processes. For instance, there have been reports about the
(Space-O Infoweb 2014); (c) come with bookmarking abilities availability of apps that: (a) offer pipe engineers various envi-
(American Geosciences Institute 2016a, 2016b; Putranto ronmental data and parameter-related information that must be
2016a, 2016b; Sidorov, 2017); (d) offer both bookmarking considered for ensuring appropriate pipe selection and control
and custom content features (Eros Apps 2016; Hybrid when natural gas weight and volume computations or natural
Dictionary 2016; Offline Dictionary Inc. 2016; Dener gas development is under way (FPC Ltd. 2017); (b) allow
2017a) and (e) have added bookmarking and share features engineers to easily identify all dimensional data on drill pip-
(LAQMED 2016; MobiSystems 2017a, 2017b). ing, casing, and tubing using the pipe outside diameter and
In most cases, mineral and rock dictionaries list images, weight (Uakanov 2014a); (c) provide information on various
describe the types of minerals and rocks, include chemical pipes that are used frequently at oil drilling and production
formula information, and offer information on the rock- sites (tubing properties and drill pipe properties depending on
forming minerals, colors, hardness, and other physical prop- the size of casing) (Oil WellApps 2015); and (d) compile
erties and text-based descriptions. Feature-specific categoriza- many equations that are used in oil and gas engineering
tion of the mineral and rock dictionary apps reveals the avail- (Munro 2013). The released apps in geology include a color
ability of apps that: (a) offer basic features and bookmarking chart app (Scott 2016) that allows color comparisons during
abilities (Ng 2013; Jourist Verlags GmbH 2013; Excellentis geological field surveys for understanding and identifying var-
2014; EasyStreet Apps 2017); (b) provide both basic and ious Earth materials such as soil and rocks.
bookmarking features and 3D visualization of crystal forms The map applications entail simplifications of all or parts of
(Tasa Graphic Arts Inc. 2014; Grupo de Percepción the Earth’s surface and represent the information on planes
Computacional y Sistemas Int. 2015); (c) show the optical according to certain scales. The apps are categorized into var-
microscopic images of minerals (Chakraborty 2016a; ious types of maps depending on the subject they try to con-
Apopei 2017); (d) offer various criteria for mineral categori- vey. Map applications generally offer visualized information
zation and related lists (Fig. 4c, Chakraborty 2016a, 2016b); on each subject/topic using Google Maps or satellite images as
 Earth Sci Inform

the basis for such visualizations. The map apps examined in including texts, photos, videos, illustrations, and maps (Tasa
this study have prices ranging from $0 (free) to $10. Some of Graphic Arts Inc. 2016). The geological tour guide application
the examined apps offer: (a) earthquake maps including real (Jeju Tourism Organization 2015) offered by the Jeju Island in
time-based updates on and alerts for worldwide earthquake the Republic of Korea, that is, a UNESCO-designated world
events (e.g., time, location, and scale) (Ackermann 2016; geopark, familiarizes visitors with the island’s geological at-
Barouline 2016a, 2016b; Artisan Global LLC 2017; Blue tractions and tourist sights, major attractions, and hands-on
Rocket Inc. 2017); (b) soil maps that display surface-soil prop- geo tour information programs that include geo trails
erties and allow users to enter the data and transmit them to the (courses) of the island.
databases (British Geological Survey 2013a, 2013b); (c) geo-
logic maps that indicate national-scale or state-wide bedrock
geology information, stratum information, soil boring logs,
Applications using built-in sensors
bore hole locations, or geological elements such as faults
and rocks (Fig. 4d, Integrity Logic 2009a, b, c, d, e; 2010a,
More recent editions of smartphones have built-in sensors that
b, c, d, e; British Geological Survey 2013c, 2016; Itacasoft
allow: (a) the rotation of the screen view depending on the
2014; British Geological Survey 2015; Geobyte Europe S.L.
position of the viewer; (b) the rotation of the map-screen ori-
2015; Geological Survey of NSW 2015; Gerardini 2015; SGU
entation; and (c) other similar convenient features (Lane et al.
2015; Civil Engineering and Development Department
2010). These sensors are capable of detecting properties relat-
2016a, 2016b; Hunt Mountain Software 2016; Regents of
ed to each axis (x, y, z) and can measure the electromagnetic
the University of Minnesota, 2017; Washington State
field at the spot, where the smartphone is located, and the
Geological Survey 2016a, 2016b; UW Macrostrat 2017a,
acceleration upon the device. Table 3 summarizes sensors that
2017b); (d) mineral maps that show mine distributions,
are built into smartphones.
mine-specific key mineral types, soil quality, and mining-
Using these sensors will allow the user to acquire physical
related information (Barouline 2016c, 2017a; Doss 2016);
property information on the device itself and various environ-
(e) sinkhole maps that list the information on the sinkhole
mental factors; unified or multifaceted applications of the sen-
status in the U.S. state of Florida (e.g., location,
sors allow the collection and visualization of data that rarely
characteristics; Femmer 2011); and (f) volcano maps that offer
become available in traditional desktop computer software
volcanic site status information (e.g., location, history) and
(Lee et al. 2013). Section 4 examines the cases in which such
issue alerts when volcanic activities are detected (British
built-in sensors have been implemented for geosciences.
Geological Survey 2017; Barouline 2017b).
Related applications are roughly divided into two categories:
Tour guide applications provide wide ranges of geotourism
data collection and visualization. This section also examines
information that will help with the introduction and tours of
the characteristics of commercially available representative
geological attractions with geological significance. The main
applications (cases). Other cases with new attempts made
targets of these apps are parks that are designated as such by
through sensing, although never released for commercial uses,
the state in recognition of their geological value. The informa-
include: (a) Measurement of the groundwater table depth
tion offered through the apps include: (a) maps (general maps,
using proximity sensors (Dong and Li 2014); and (b)
geologic maps) of each attraction, locations, and how to reach
Visualization of the 3D geological structure using AR
them; (b) sufficient description of geological characteristics,
(Mathiesen et al. 2012).
principles of origin and history along with photos, illustra-
tions, and videos (guides); and sometimes (c) other tourism-
related information based on the location of the user such as Data collection software
the nearest geological tour sites and trail tracking courses. The
specificity of such information distinguishes the tour apps Table 4 presents various sensors that are data collection tools
from other more general tour guide applications, which do available on smartphones. The sensors used in geosciences
not focus on geological attractions. The geotourism apps in- include a number of geological structure measuring applica-
vestigated in this study have prices ranging from $0 (free) to tions that make comprehensive use of, especially, accelerom-
$5. The application of the Arches National Park in Utah in the eters and digital compasses among others (Table 4).
United States includes navigation features that allow users to Accelerometers measure the physical acceleration that
quickly and easily locate the geo tour hiking courses and at- operates on the device; hence, they are able to measure the
tractions; users can see the world’s widest variation of natural gravitational acceleration as well. Digital compasses, on the
arches and rock peculiarities in the park (GuideMe Travel other hand, are capable of measuring geomagnetism. Using
LLC 2013). Moreover, information regarding the park’s geol- both of these gadgets will therefore allow users to calculate the
ogy and topography (origin and uniqueness) and major tourist position of the smartphone on coordinates using real world
attractions (e.g., arches) is offered in form of various content information and to detect the ground behavior and vibrations.
Earth Sci Inform

Table 3 Built-in hardware

sensors of smartphones (Apple Sensor Functionalities Units of measure
2017; Google 2017a).
Accelerometer Measures acceleration force m/s2
Magnetometer Measures the ambient magnetic field μT
Gyroscope Measures a device’s rate of rotation rad/s
Proximity sensor Measures or determines the proximity of any object cm, or Boolean
values
Ambient light sensor a) Measures the ambient light level Lx
Optical image sensor Acquires optical imagery –
Temperature sensor b) Measures the temperature of the device or specific internal °C
component
Ambient temperature Measures the ambient temperature °C
sensor a)
Microphone Converts sound wave into electric signal –
Barometer c) Measures the ambient air pressure hPa or mbar
Humidity sensor a) Measures the relative ambient humidity %

Notes
a)
Not compatible with iOS platform.
b)
Can be used only for OS-internal purposes and not by developers.
c)
Only relative altitude change to be read on iOS platforms, no pressure reading available.

Moreover, the mentioned sensors are digital sensors and measurement/survey task. With a geological structure typical-
thus are capable of extremely rapid individual measurements ly being a static structure, superposing the phone on such a
compared with more general-purpose analogue sensors by structure would turn the smartphone-sensed acceleration into
calibrating the measurement intervals to be extremely small gravitational acceleration due to the lack of movement of the
when sensing properties. However, the noise generated by device. Furthermore, when there is no artificial or natural
digital sensors will alter the output of the sensors, even when structure generating magnetism or localized magnetic fields
the physical conditions of the device or its environment do not on the surface concerned, the magnetism that is measured at
change. Because the OSs don’t always offer correction tool for the same spot will equal the sum of the smartphone’s own
such noise, users can apply a proper tool in parallel that can magnetism generated by its operation and geomagnetism.
eliminate the changes (Ozcan et al. 2011). Ordinary smartphone OSs, such as Android and iOS, have
The mentioned measurement applications are beneficial in correction algorithms in place to neutralize the interference
that they incorporate the tools existing in physical form into by their own electromagnetic fields and can even require the
the smartphone programs as apps, that is, a virtual form, thus user for correction based on the necessity for such neutraliza-
retaining their functionality, yet increasing their measurement tion. Provided that the correction of such interference is com-
convenience or speed. Moreover, plenty of apps empower plete, the results of the measurement obtained under static
users to tap into extra features available on smartphones, such conditions should be equal to the geomagnetism. Hence, the
as communication, to ensure multifaceted usage and to carry smartphone position in real terms becomes computable.
out tasks on job sites that go beyond the realm of mere The type of geological structure that is the target of mea-
measurement. surements in geology or engineering geology could be planar,
such as faults and joints, or linear such as folds or schistosity.
App for orientation measurement of geological structures Just as there are differences between the measurement/survey
techniques using conventional equipment, measurement/
All geological structure measurement or surveying applica- survey or calculation methods using smartphones will be dif-
tions available for smartphones have built-in sensors upon ferent as well, depending on the geological structure.
they operate. Most of such applications work by the principle Therefore, many applications allow users to predesignate their
of convenience, instead of using a separate, independent cal- measurement target or select the type of measurement target.
ibration scheme or any other particular measurement method- A total of 17 apps applying sensors for geological structure
ology. Such applications regard the position of their measurements/surveys were investigated in this study. They
smartphone that is superposed upon the structure to be range widely in price, from $0 (free) to $101, depending on
measured/surveyed by the phone as the orientation of the offered features (Table 4). Based on the platform type, the 17
structure concerned and accordingly carry out the apps are divided into: (a) 9 Android-exclusive apps; (b) 5 iOS-
 Earth Sci Inform

Table 4 Data collection

applications Field Name Platform Price Remark

G eGEO Compass Pro by A $7 Foi 2016

IntGeoMod
G FieldMove A,I $29.99 Midland Valley Exploration Ltd. 2016a
G FieldMove Clino A,I Free Midland Valley Exploration Ltd. 2016b
G GeoClino for iPhone I Free Geological Survey of Japan, AIST
2016
G Geocompass A Free Innocenti 2012
G GeoCompass 2 - Geologist’s I $2.99 Lin, 2015
Compass
EG GeoID I $5.99 Engineering Geology & GIS Lab.,
SNU. 2014
G Geological Compass Full A $6.72 ThSoft Co., Ltd. 2015
G Geology Sample Collector A Free Major Forms, 2015a
EG Geostation A $101 Terrasolum. 2014c
G Lambert I $2.99 Appel 2017
G PocketTransit A,I Free / R&W Scientific 2016
$4.99
G Rocklogger A Free RockGekko 2017
G Strike and dip A Free Major Forms 2015b
G Strike and Dip I $4.99 Hunt Mountain Software 2017
G Structural Compass A Free Apps Medion 2017

exclusive apps; and (c) 3 apps compatible with both platform needed for field surveys, thus eliminating the need to carry
types, 2 of which are apps (Midland Valley Exploration Ltd around separate mapping S/W and geologic maps. Each mea-
2016b; Vaughan et al. 2014) that have removed only some of surement or survey location can be automatically mapped
the features (e.g., measurement) from paid applications using the built-in GNSS function. When needed, the mapped
(FieldMove). Hence, only 2 applications (FieldMove, information can be selected to enter images and notes.
PocketTransit) are operable on both platforms. A vast range The functions of GeoStation, whilst being a versatile
of available features were observed, ranging from the most measurement/survey-based application similar to FieldMove,
basic and essential feature (orientation measurement) to its focus mainly on geotechnical engineering purposes (Fig. 5b).
application in Global Navigation Satellite System (GNSS) The measurement/survey features of GeoStation are similar to
tracking to photographing and recording features to automatic those of other applications. The targets to be measured/
field mapping and stereographic projection. Moreover, some surveyed are limited to discontinuities including bedding,
applications were found to be able to assist in field surveys joints, and faults. Each of the measured/surveyed data points
and analysis through engineering analysis features. on the orientation of the discontinuity, length, separation, and
FieldMove is an integrative application for field mapping. roughness are required to be recorded separately. Based on the
In addition to the mentioned measurement features, the app data inputs, the RMR and Quality Index (QI) can be deter-
has built-in features such as (a) mapping of measurement re- mined. Additionally, the saved measurement/survey data and
sults for each geological structure; (b) drafting features to records, including extra photos and memos, are controlled by
indicate the surface soil survey results for each area; and (c) the project. Each of the survey data points is transmitted in
stereographic projection features used mainly for abbreviation container format, such as comma-separated values (CSV), or
in 2D and indicating the results of geostructural measurement can be printed out as report in portable document format
results (Fig. 5a). Because this app selects its measurement (PDF).
target from preestablished group categories, there is no need GeoID, although similar to FieldMove in terms of function-
to reclassify the measurement results afterwards. For measure- ality (measurement, stereographic projection,) and construct-
ment targets, the app allows the predesignation of the typically ed overall as an ordinary geological survey tool, has an added
used types of structures (e.g., linear, planar) and more detailed feature of engineering geology analysis (Fig. 5c). GeoID can
designation of particular excess head or rock mass types to be designate its targets as either planar or linear structure only
observed at the job sites later on. Furthermore, the app allows and is configured such that it changes the measurement meth-
the mounting/inclusion of any geologic maps and diagrams odology for each target to be measured/surveyed. The data
Earth Sci Inform

Fig. 5 Representative smartphone applications for field investigations using built-in sensors. (a) FieldMove, (b) GeoStation, (c) GeoID
 Earth Sci Inform

entry methods offered are either direct or through sensors; the events with a magnitude at or above certain levels. The sig-
app comprises simple structural calculations such as that of a nificance of using smartphones for this purpose, however, lies
planar structure including two linear structures. The project- in the fact that crowdsourcing-based data collection can lead
specific measurement results are indicated in the stereographic anonymous masses to participate in the collection of quake-
projection unit. Instability analysis to be performed from this induced vibrations and volcanic eruptions that do not require
display will assume the planar structures to be discontinuities specific measurements or monitoring by a small number of
and thus allow analysis of stability against the slope with a experts. Based on the collected data, high-density, massive
particular angle and direction of inclination. databases can be established.
Seismo Cloud is a similar example. This application per-
forms crowdsourced earthquake detection in a similar manner
Earthquake sensing as MyShake but is operable on platforms such as Raspberry Pi
and Arduino in addition to smartphones. While handheld de-
Normally, observations of surface/grid vibrations, such as vices such as smartphones typically have difficulties in
earthquakes, are carried out at the observation posts located predicting vibrations such as earthquakes, Seismo Cloud al-
across the globe. Nevertheless, it is not feasible for users to lows the use of non-smartphone and economized embedded
know the vibrations that are detected in a region that is not in devices as fixed platform and hence the creation of highly
any close proximity to the concerned observation post. In reliable low-cost seismometer networks.
realistic terms, given such difficulties with respect to universal
observation and detection, using smartphones to identify the
magnitude of seismic events could be a promising tool, not Data visualization software
only in terms of personal interest but also in terms of universal
data collection. Various sensors mounted on smartphones not only allow data
For such smartphone-based measurements of seismic mag- collection through measurements/surveys but can be applied
nitudes to have a practical significance, the measured values to visualization. Utilizing the fact that the position of a
must be provided in numerical terms, for example, accelera- smartphone can be measured, AR is used, providing informa-
tion in time (m/s2) or seismic magnitude, and the smartphone tion on the phone’s current position in combination with in-
must have corresponding features such as the storage and formation on the real world. The AR technique can intuitively
transmission of measured data. Table 5 summarizes the corre- visualize the location or structural information concerning the
sponding applications; only those with academic significance mass. As geoscientific information and data include many sets
are introduced in this paper. of such information (grid geology, geological structure), visu-
MyShake (Kong et al. 2016) is an application developed by alization based on AR can be effectively applied to wide
the Berkeley Seismology Lab. The application was conceived ranges of endeavors such as field geological surveys and
based on the observations that smartphone sensors can detect education.
earthquakes and that smartphones are concentrated with a In general, AR can be categorized into three types: (a)
high penetration ratio in almost all locations populated by Using a camera to capture the image of a unit having a partic-
people. Based on these observations, each smartphone unit ular configuration (e.g., marker, object) and recognizing the
is used as a portable seismometer that is connected to the information via pattern recognition technology to indicate a
network. In the event of an earthquake, the seismic waves start particular piece of information near the location in question;
to travel from the epicenter outward. Hence, the seismic (b) using the device’s location information, the target’s relative
source (origin) and magnitude can be traced back from the location information, and other sensor-detected information to
acceleration and seismic wave arrival time that are sensed at indicate information on the surroundings; and (c) combining
each location. Although smartphones are now an everyday the aforementioned types (Daponte et al. 2014). The first
mobile device, their sensitivity and accuracy cannot surpass method has merits because the actual target can be substituted
those of seismometers and the device can only detect seismic or additional information/data on the target can be indicated;

Table 5 Seismometer
applications Name Platform Price Remark

iShindo – Seismic Intensity I Free Hakusan Corporation 2017

myShake A Free UC Berkeley Seismological Laboratory 2017
myVibrometer I $1.99 Natalini 2013
Seismo Cloud A,I Free Informatica@sapienza 2017
Seismometer I $1.99 FFFF00 Agents AB 2013
Earth Sci Inform

however, the actual target must always be recorded/ The boring log information, unlike geologic maps, is repre-
photographed. The second option allows the calculation and sented in form of dots in a number of locations; hence, visu-
indication of the relative locations of other sites once the cur- alizing such difficult-to-locate information at sites through AR
rent location of the device is established/entered; however, it is will expedite the search for drill holes using concentrated vi-
significantly affected by the GPS-based location accuracy, sualization of the virtual location to the users’ advantage. Note
angle of direction via digital compass, and other sensor- that the boring log data are presented in a particular format and
related factors (Lee et al. 2015). as such, it is difficult to treat the data as individual document
The AR technology has started to be noticed only recently when a number of bore log data are present in certain areas or
and is now expanding the scope of its application, with focus regions. In contrast, the new method benefits the site’s field
in the entertainment industry. Hence, not too many case stud- surveyors by either visualizing the log information in concen-
ies exist. However, three recently released geoscience studies trated form or allowing analysis of the target.
provide good examples of the applicability of AR that utilizes UMineAR (Suh et al. 2017) is a mobile tablet app that
different specific technologies. enables users to rapidly identify underground mine objects
Unearthing 3D modeling (ARANZ Geo, Ltd 2016) is an (drifts, entrances, boreholes, hazards) and intuitively visualize
AR app that utilizes a marker. From the viewpoint of AR them in 3D using a mobile AR technique (Fig. 6). UMineAR
technology, this application executes only very basic roles. consists of search, AR, map, and database modules. The
When the app is activated, the recorded image is shown using search module provides data retrieval and visualization op-
the camera in real time; when the producing company’s par- tions/functions. A case study showed that UMineAR applica-
ticular marker is projected onto the screen or is printed and tion is suitable for onsite visualization of high-volume mine
shown on the marker, the geological model is established on GIS data based on geolocations; no specialized equipment or
the marker. The model allows shifting of the phone’s perspec- skills are required to understand the underground mine
tive as if the real object was there at the location; the modeling environment.
can be selected and rotated on the screen. Divided into several
parts, the model allows 3D viewing by eliminating or marking
a particular section. This technique is widely applicable in Limitations and future perspectives
many fields (e.g., education) because it offers experiences that
are different from the typical 3D modeling projected onto a 2D Hardware limitations
screen through real-world perspectives of a 3D object.
The app iGeology3D (British Geological Survey 2012) is Limited capacity
an application of 3D AR technology to the generic geologic
map application iGeology (British Geological Survey 2013c, In relation to the improvement made with respect to the
2016). With geologic maps with clearly established coordi- smartphone penetration ratio, advances in the hardware tech-
nates, the coordinates are converted to the relative location nology have endowed new ordinary editions of smartphones
using the smartphone’s location and then projected in 3D. with merits such as, most of all, smaller thickness and smaller
The result is information visualized on geologic maps, with weight (physical indicators, hardware-wise), longer battery
the smartphone’s face direction serving as the reference. Using duration, and lower price. The smaller hardware and longer
such an approach, this app combines geologic maps built-in battery life are trade-offs, whilst the lower-price factor is in
the camera’s focus, thus offering a visual, where the current conflict with all other factors. Satisfying all of the factors,
location is superimposed with the corresponding geologic therefore, would necessitate the adoption of smaller, lighter,
map. Through the scheme, personnel can intuitively check lower-voltage, and cheaper parts (Middlemiss et al. 2016),
the geological information of a certain area or region without ultimately limiting the phone’s processing performance and
having to separately refer to the geologic map at the job site. storage capabilities.
Considering that the existing geologic maps are ultimately 2D The majority of the latest versions of smartphones have an
information, despite the convenience with which the informa- built-in low-voltage processors and flash memory-based stor-
tion is obtained on the app, the researcher who wishes to refer age (Daponte et al. 2013), which are in most cases relatively
to the information would have to perform a comparison to less competent in speed and capacity than the parts that are
ensure the use; iGeology3D, however, has abbreviated these mounted in desktop or notebook computers. Considering the
cumbersome steps, providing greater convenience to field sur- characteristics of geosciences that handle 3D spatial data and
vey crews. fast-processed data regarding vast spans of areas, such limita-
BoreholeAR (Lee et al. 2015) is an AR-based app that tions of smartphones will lead to limitations in the utility be-
displays boring log information that is used as reference infor- cause of the device’s failure to perform computations and
mation for underground geological data. Technically speak- reception of necessary analysis data that are being handled
ing, this app uses the same location-based AR as iGeology3D. by desktop computer hardware, although the same challenges
 Earth Sci Inform

Fig. 6 Abandoned mine hazard

site investigation using
UMineAR

are being noted in the existing computing environment using Open Source Geospatial Foundation 2017a, b). Such an ap-
desktop computers. As reviewed in Sections 3 and 4, the ma- proach would be appropriate for scenarios, where large-
jority of apps that have been released so far can only carry out volume data need to be processed continuously by a number
simple equation applications, search, and one-time analyses; of users because this scheme would allow most analysis and
apps capable of handling or analyzing large-volume data are processing that are implementable in existing manners and yet
yet to be released. incorporate the merits of smartphones. Furthermore, this ap-
Although the processing speed of smartphone processors is proach would allow the smartphone applications to be created
rapidly improving (Lin et al. 2016), there still remain limita- web-based by transferring the massive processing load and
tions in the device’s capacity for handling desktop-level tasks. functioning to the server. An appropriate example would be
Technologies to compensate such limitations are being devel- the visualization of geologic maps as introduced in Section 2.
oped. Note in particular that a number of solutions, such as the Note that a multifaceted solution such as cloud computing
commercially available S/W ArcGIS Server and the open might be a beneficial for geological surveys for which access
source-based MapServer and GeoServer programs, have been to data by multiple users and the handling of bulk data are
developed to divide the task into two levels: the server is in necessary (Wu et al. 2015). In these server-based schemes,
charge of primary data processing and storage, while the where the original data and their handling platforms are all
smartphone takes care of low-load tasks, such as giving in- within the server, the role of smartphones is diminished.
structions and visualizing pre-rendered data, thus together However, smartphones can still execute their original roles
making the application more client-oriented (Esri 2017; such as sensor-based data collection and crowdsourcing;
Earth Sci Inform

hence, their importance remains. Moreover, during those more Device fragmentation
original tasks, the device can help to reduce the consumption
of energy that is needed for computation and other tasks Smartphones with many types of hardware packages are avail-
(Altamimi et al. 2012). To sum up, the mentioned apps could able, which could vary in terms of size, performance, extra
be appropriate models for field survey during which users features, and other characteristics, even when the same plat-
cannot rely on outside power supply. form is used. Such diversity satisfies the purpose, taste, and
preferred pricing of smartphone users who represent vast
ranges of clientele. Sensors, which only recently are being
Sensor quality built into the phone as pressure meters, are included based
on the type of hardware concerned. Hence, there are differ-
Collecting information/data on physical properties from real- ences in terms of which particular function(s) can be fulfilled
world sources, that is, one of the most critical tasks in geosci- by which sensors. Each hardware type comes with different
ence, can only rely on sensors unless it is otherwise achievable sensor types, locations within the device, and the degree of
through researchers’ direct, first-hand observations. The sen- impact on other parts. Even the size and form of chassis vary
sors play a pivotal role in field property surveys, alongside the depending on the model.
smartphone’s mobility, internal data-processing capability, Substituting the conventional measurement/survey equip-
and data transmission features. Hence, it is indispensable that ment used in geoscience by smartphones would require to
the device’s hard- and software technology is further devel- consistently simulate the output delivery system of the equip-
oped to enhance the measurement precision and accuracy and ment and their characteristics such as accuracy, precision, and
ensure the scope of its utility/applicability. sensitivity. However, as mentioned before, measuring the data
Built-in sensors of smartphones are sensors that are based using the same algorithm would still not guarantee outputs
on the microelectromechanical system (MEMS); hence, the with consistent quality, implying the inevitable problem that
device can be smaller and lighter. However, the sensors are all smartphones (models) would need to be tested to accom-
characterized by a relatively lower accuracy, precision, and plish accurate measurements of the specification of the devel-
sensitivity because they are incorporated into the device to oped applications. For instance, the seismometer application
provide convenience for users (Syed et al. 2013). The ratio- introduced in Section 4 uses sensors that come in only one
nale notwithstanding, the sensors that are built into the more type, that is, an accelerometer, implying a relatively smaller
recent models of smartphones are powerful enough to be uti- impact of the sensors. However, if the hardware is not
lized for measurement/survey purposes. As mentioned in completely fixed onto the vibrating surface, the degree of
Section 4, the calibration of the noise and skewness errors of the phone’s movement induced by vibrations, such as those
sensor-produced output values are somewhat of a burden to during an earthquake, would vary depending on the weight,
the developers. Moreover, because the majority of electronic surface material, and orientation. Hence, calibration would be
parts that make up the device are placed on the small main necessary for each type of hardware. Some of the seismometer
board due to the hardware characteristics, the digital compass applications are trying to solve this problem to a certain degree
(magnetometer) becomes particularly vulnerable to the effects by offering calibration methodology (Smart Tools Co. 2017).
of such parts, to varying degrees (Ozyagcilar 2015). Hence, An accelerometer, compared with a digital compass, re-
using the measured data would inevitably make prior calibra- quires less calibration by the user or developer (Lee et al.
tion necessary. Normally, the OS carries out the calibration, 2013) and hence less changes to the outputs due to differences
providing corrected values. in hardware, even when the built-in sensors are used. In case
As for the hardware aspect of the sensor issue, sensors are of a digital compass or gyroscope that detect electromagnetic
continuously improved, just as the processing speed and stor- fields, the outputs can be significantly affected by differences
age capacity. For instance, the latest developed MEMS has a in the internal layout of parts. Such impact could be mini-
sensitivity so powerful that it allows the device to measure mized by offering equipment-specific appropriate calibration
even Earth tides (Middlemiss et al. 2016). However, prob- methodologies or using external hardware with independent
lems, such as internal interference, are inherent to the device’s built-in sensors.
internal construction and as such cannot be solved with im-
provements in the sensing capability alone. The development Software-related issues
of calibration algorithms and selection of appropriate
measurement/survey methodologies must therefore accompa- Difficulties caused by various OS environments
ny sensor-improving endeavors (Syed et al. 2013). An alter-
native should also be considered, where key sensors are The values sensed by sensors built into smartphones will be
placed into separate external hardware and then connected to provided via the respective OS’s API. The developers can use
the smartphone. these values to execute calculations such as that of the phone’s
 Earth Sci Inform

position information. Using the same type of sensor, however, updates is not in place, compromising the core functions such
would still require care and caution because the output- as measurements/surveys and visualization using the sensors.
delivering method or pre-processing steps differ. For instance, Failing to modify the altered orders could lead to the failure
the unit of measurement used by the Android-based acceler- of the program in operating as intended or executing the func-
ometer indicating the outputs is m/s2, whereas the unit adopted tions all together. These problems could make the use, main-
by iOS is g (9.81 m/s2). Moreover, despite the same orienta- tenance, and repair of applications difficult in combination
tion of the 3D perpendicular coordinates based on the device with fragmentation problems mentioned in Section 5.1.3 be-
as reference, the output orientations are opposite due to the cause not all equipment can be updated to the latest OS ver-
difference in the acceleration concept (Apple 2017; Google sion nor do all applications operate on the latest OS version.
2017b). Programs executing the same role would therefore From the viewpoint of users, the discontinuation of OS up-
still need to process the sensed values differently depending dates by the manufacturer of their smartphone would mean
on the type of each platform. that they cannot use the latest OS version. Hence, if the appli-
The disclosed details, such as the sensed values, can be cations that they are using develop applications by using the
addressed by simple modification of algorithms. However, OS version required by the latest API, the users cannot use
the undisclosed items, such as pre-processing and correction their applications. Furthermore, the developers face difficul-
methodologies for sensed outputs, would need to be identified ties in manufacturing applications capable of accommodating
against the software’s outputs through additional testing for the largest possible number of devices such that their clients
each hardware type or internally corrected algorithms would who use varieties of OS versions can be satisfied. The devel-
need to be built into the application instead of using the opers would need the continued involvement of maintenance
corrected values. The differences between different OS- personnel and might experience continued mobilization of
based data outputs could be minimized because each OS of- relevant costs and expenditures.
fers sensed values that are not precorrected.
Each OS, such as Android and iOS, uses different native
programming languages for development purposes; their Application sandbox
equipment and S/W programs also differ. Hence, the applica-
tion development for each OS would require skills that allow The Android OS and iOS implement limited authorization
the use of each environment and development language areas called sandbox to ensure security. With this implemen-
(Goadrich and Rogers 2011). This becomes a factor that will tation, data storage space accessible from each application is
increase the personnel developing applications that operate on strictly allocated and any violation of such limits by access
each OS and development and maintenance costs. In cases, attempts are either prohibited or special authorization is re-
where the process of application operations does not require quired (Ahmad et al. 2013). Hence, even those applications
the use of a native API or very little of it, the majority of the that are built into the same device would still undergo relative-
contents, except for the most integral part, could be employed ly more complicated processes of data sharing or transferring
as OS-common applications (e.g., web app or hybrid app; when compared with the desktop S/W environment. Note that
Godwin-Jones 2011). Additionally, using multi-OS-operable bulk data that require the preservation in single storage and the
languages, such as C++, that operate on Android and iOS sharing thereof could particularly be vulnerable to such a
could be a viable alternative to avoid overlapping work with problem. This very problem can be an obstacle for geoscience
respect to the development of the same content in different endeavors that use many maps, videos, and other spatial
languages. datasets. If large-volume data need to be entered and retrieved
in a series of steps, users might experience difficulties such as
having to create applications by combining all related features
Fast-changing APIs to avoid problems with respect to security and inconvenience
in use during data sharing.
Smartphone OSs undergo faster API updates than PC OSs due The aforementioned problems might not be so serious
to the active development and expansion of features. An up- when the data size is small because then a safe and user-
date in the key version of a certain OS would also require an friendly method can be used such as transferring the entirety
update of corresponding applications. For instance, Android of data between applications. However, when considering the
undergoes approximately more than 100 API updates each use of smartphones as a versatile scientific tool, appropriate
month, thus requiring rapid modifications of hardware, user solutions are necessary. A viable solution would be, sharing
interface, and web-related items (McDonnell et al. 2013). data by using external storage, such as cloud storage, or as
Considering the characteristics of current smartphone models, mentioned in Section 5.1.1, using server-computing to avoid
with increasingly larger numbers of sensors being built in, problems associated with storage space, data redundancy, and
problems likely occur when the timely response to such security issues.
Earth Sci Inform

Conclusions Compliance with ethical standards

In this paper, a large number of commercial applications avail- Conflict of interest The authors declare that they have no conflict of
interest.
able in the field of geosciences were investigated and the areas
of use and major features of those applications were exam-
ined. The results of the review revealed many cases in which
the existing recording, analysis, and measurement methodol-
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