The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015

International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

IMPLEMENTATION OF AN UNMANNED AERIAL VEHICLE SYSTEM FOR LARGE

SCALE MAPPING

S. B. Mah a, C. S. Cryderman a, *

a
Underhill Geomatics Ltd., 210A, 3430 Brighton Ave., Burnaby BC, Canada V5A 3H4 – (bmah, ccryderman)@underhill.ca

KEY WORDS: UAV, Drones, DIY, Mapping, GNSS, Autopilot, Aerial Photography

ABSTRACT:

Unmanned Aerial Vehicles (UAVs), digital cameras, powerful personal computers, and software have made it possible for
geomatics professionals to capture aerial photographs and generate digital terrain models and orthophotographs without using full
scale aircraft or hiring mapping professionals. This has been made possible by the availability of miniaturized computers and
sensors, and software which has been driven, in part, by the demand for this technology in consumer items such as smartphones. The
other force that is in play is the increasing number of Do-It-Yourself (DIY) people who are building UAVs as a hobby or for
professional use. Building a UAV system for mapping is an alternative to purchasing a turnkey system. This paper describes factors
to be considered when building a UAV mapping system, the choices made, and the test results of a project using this completed
system.

1. INTRODUCTION hardware and software movement. The Web is a source of

information, knowledge and expertise, and it also provides
Unmanned Aerial Vehicles (UAVs) are now a viable tool for forums for like-minded people to come together to pursue
taking aerial photographs for photogrammetric purposes. common interests. Experts can collaborate on projects and
However, when acquired from commercial suppliers in a turn- design/build hardware and software that is either not available
key format, they are still quite expensive, costing many tens or commercially or is very expensive. The Web also serves as a
hundreds of thousands of dollars. This limits the business case huge test bed which can reveal faults and/or shortcomings, as
for purchasing a UAV by professionals. There is an alternative, well as providing ideas for continuing development and
and that is to build the UAV yourself. This is not a new improvement.
concept (Karakis, 2011) but the increased availability of open
source hardware and software has made it more practical The recent rise of the "Maker" movement (Morin, 2013), where
(Mészáros, 2011). Not only do you save on capital costs, but people are applying technology to their DIY projects, is an
you also gain the knowledge and experience which you will indication of the extent that technology is the new hammer and
need to operate and maintain the UAV in the long term. The wood focus of DIYers of the last generation. Now, with the
DIY approach to implementing a UAV system frees the user proliferation of 3D printers and CNC machines, a person can
from dependence on a third party. The ability to DIY an make things only a large manufacturer could - merely a decade
affordable UAV system opens the practice of aerial ago. This has implications for manufacturing companies.
photogrammetry to a variety of people in, and out, of the Companies that can mass-produce consumer items efficiently
geomatics industry. will not be affected. However, companies that produce specialty
products for a small market will feel the effects of the upward
In the past, aerial photography could only be carried out using pressure of the DIY, or Maker, revolution.
full scale aircraft and large format cameras. Such a system
would cost several hundred thousand dollars. Now it is possible A good example of the DIY UAV movement on the Web is
to purchase a UAV aerial photography system for one-tenth of DIY Drones (diydrones.com). This website, started by Chris
that. Similarly, a DIY system is again an order of magnitude Anderson of 3D Robotics, is up to 64,000 members (Coyle,
cheaper than a commercial UAV system. 2015). Members meet online to share ideas and help each other
on all aspects of UAVs. Anderson, formerly of WIRED
A UAV system is the integration of several mature magazine, saw the growing DIY movement in UAVs
technologies. These include computers and software; digital (Sollenberger, 2014) and quit his job to start 3D Robotics
radio communications; GPS, inertial, and other sensors; (WIRED Staff, 2012), a company that sells complete UAVs as
miniature aircraft; and high energy density batteries. The well as components to DIYers.
increasing miniaturization of electronic components combined
with increased computing power and decreasing costs have Specialty products with low consumer demand are expensive
made building your own UAV possible. because the development and manufacturing costs are borne by
a small market. In the technical fields, this is compounded by
The other areas which are crucial to DIY are open source the increasingly short life of a product due to advancing
software/hardware and the World Wide Web (Web). The two technology. The UAV photogrammetry field fits into this
are inter-related as the Web has enabled the open source category. Complete UAV photogrammetry systems have a

* Corresponding author

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 47
 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015
International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

limited market and as a result are expensive. However, the Other means employed to make this consumer camera be more
individual components which make up a UAV photogrammetic “metric-like” included: turning off piezoelectric sensor
system are quite common and are readily available at cleaning, and stabilizing the camera lens mount.
competitive prices. The components of a typical UAV system
for photogrammetry are:
2.2 Fixed-wing or Rotary-wing?

 miniature aircraft - hobbyist grade model aircraft are There are a variety of aircraft configurations, from fixed-wing
available in many forms and sizes for very reasonable to rotary-wing, which can be used for aerial photography
prices. An unassembled fixed wing aircraft kit with a purposes. Factors to be considered when deciding on the best
wingspan of 1.5- 2.0 metres can be purchased for configuration are:
C$100 - C$150;
 load carrying capacity - weight and volume

 electric motor propulsion system with Lithium  flight speed

polymer batteries and charging system
 flight stability

 radio control system - a complete radio control  flight range - distance covered
system complete with transmitter, receiver, and four  operating environment - take-off and landing area
or more servo actuators
 physical size
 autopilot system - Arduino based APM auto-pilot  durability and maintainability
computer with free Ardupilot open source software
and Mission Planner software for system
 cost
configuration, flight planning, and post-flight analysis The size of the camera combined with the need to cover up to
one, or more, square kilometres for mapping purposes limits our
 radio telemetry system - 915 MHz radios choice of airframes to a fixed-wing configuration. The
 ground station - Android pad computer running free advantages of a multi-copter, being able to take off and land
open source Droid Planner software vertically, and to hover, are negated by its limited range. The
disadvantage of a fixed-wing aircraft is the space required for
 digital camera take-off and landing, but this is less of an issue when mapping
larger areas, where generally, open spaces are available for
 data processing computer
take-off and landing. Take-offs are less of an issue, as a fixed-
 photogrammetric software wing aircraft can be hand-launched from a small space.
Additionally, multi-copters are more complex in many ways.
The propulsion system requires at least three motors and their
2. THE STUDY UAV SYSTEM FOR AERIAL
associated electronics. They are difficult to fly manually
PHOTOGRAMMETRY
without computer stabilization. A motor failure is often
2.1 The Payload catastrophic because unlike a fixed-wing aircraft, a multi-copter
cannot glide to a landing. The complexity translates to more
maintenance and higher costs.
Based on our imaging requirements, the camera and lens
combination that we chose weighs about 700 grams. In terms of
commercially available UAV systems, this is a relative large 2.3 What Kind of Fixed-wing?
camera, both in volume and weight. Most small off-the-shelf
systems carry only smaller, sometimes lower resolution Once the UAV platform was narrowed to a fixed-wing aircraft,
cameras. there was the choice of the fixed-wing configuration. The two
The camera chosen was a Samsung NX1000 mirrorless camera main options are flying wing or regular configuration with a
with a Carl Zeiss 18 mm focal length lens. The Samsung tail. There are advantages and disadvantages to each.
NX1000 is a consumer grade camera with a 20 megapixel The flying wing is physically more compact and harder to
CMOS APS-C format sensor (23.5 mm x 15.7mm). It has a damage. However, it is less stable (more sensitive to centre-of-
shutter capable of 1/4000 of a second and tests show that it can gravity location), has a higher stall speed (must fly faster), is
fire repeatedly approximately every 0.8 second. harder to configure to carry a bulky camera, and is less visible
The Zeiss Distagon 18mm, f4 lens was designed for 35mm film in the air due to its small profile.
cameras (36 mm x 24 mm frame) and when used with the APS- Typically, a flying wing is harder to hand launch, requiring a
C sensor, only the central portion of the image projected by the catapult system. This is due to a number of reasons. First is the
lens is used. This reduces vignetting as well as producing a lack of a fuselage which provides for an easy location to grip
sharper image. The lens is used at a fixed focus (chosen as the the airframe. Second is the propeller, which typically is at the
hyperfocal distance for maximum depth of field). The aperture rear of the airframe, is in a good position to make contact with
was fixed at f5.6, which is more-or-less at the sweet spot for the launcher’s hand. Thirdly, the wing’s high stall speed makes
sharpness across the field of view. This further reduces it difficult to achieve minimum flying airspeed with a hand
vignetting without creating diffraction effects. Information launch.
about the performance of particular consumer camera/lens
combinations can be found on the Web (http:/photozone.de). The wing’s high stall speed also makes landing difficult. The
high landing speeds leaves the aircraft susceptible to damage

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 48
 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015
International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

once it contacts the ground. The damage can be accepted as a

cost of using a flying wing or a landing system, such as a
parachute, may be implemented to avoid high speed landings
(Brucas, 2013).
Installation of landing gear on a flying wing is also difficult.
This exposes the downward facing camera to the risk of damage
as every landing is a belly landing.
An aircraft, with a tail, is more stable than a flying wing. It is
larger, so is more easily configured to carry a bulky camera.
Also, landing gear can be easily added to protect the camera
lens. However, the airframe is more susceptible to damage
because of the added fuselage and tail. An important bonus of
the larger shape, though, is increased visibility at a distance,
which is important when aircraft is at the limits of eyesight.
The size (wing area and total weight) of an airplane is an
important determinant of its flight characteristics. Generally, an
airplane with a lighter wing loading (total weight / wing area) Figure 1. The Study UAV
can fly slower (lower stall speed). Additionally, a larger
airplane (more wing area) with the same wing loading as a This aircraft has low wing loading, good stability, low stall
smaller airplane will be easier to fly. This scale effect can be speed, good load carrying capacity, and is durable. It easy to
quantified by the Wing Cube Loading formula (WCL = Weight hand launch, has a good power-to-weight ratio with a good rate
/ Area1.5 where Weight is in ounces and Area is in square feet) of climb, and can land at a low airspeed in a short distance with
(Reynolds, 1989). flaps deployed. It cruises at 14 m/s and can land with full flaps
at 10 m/s.
An aircraft with a Wing Cube Loading of less than 10 would be
desirable. Such an aircraft is suitable for use as a sport model Flying this aircraft does require radio-control piloting skills and
for radio-control pilots. It would also be suitable as an UAV construction requires hands-on building, system integrating, and
because its relatively slow and stable flight characteristics. troubleshooting. However, these skills are also required in the
long term operations of an UAV.
2.4 The Study UAV
2.4.2 Airborne Components
2.4.1 System Overview
The airborne components of the UAV system consist of the
 BEVRC Skywalker 1.9 metre wingspan fixed wing airframe, electric propulsion system, radio control electronics,
aircraft of EPO foam autopilot, telemetry radios, and camera. These components
work together to perform the function of taking photographs of
 commercially available kit; requires building the ground from pre-planned positions in space. The autopilot,
an Ardupilot APM 2.6, is the part that pulls everything together.
 single electric motor
It controls the airplane and the camera when it is flying the lines
 ailerons, flaps, rudder, elevator, motor speed control over the ground to be photographed.

 fuselage modified to carry camera payload (700 The autopilot's primary task is to fly the airplane along a
grams) preplanned flight path. It does this autonomously, without any
human input. A prerequisite for this is an airplane that is
 landing gear added to the aircraft to raise the fuselage trimmed to fly straight and level with minimal control input. An
and camera above the ground when landing autopilot may be able to fly a badly trimmed airplane but its
performance in flying a precision pattern is compromised.
 optional flaps were installed in the wing to slow down
the landing speed. Also allows steeper descent into a The autopilot takes input from various sensors to control the
tight landing zone flight. It flies the UAV to waypoints using GPS for navigation.
The real-time control of the UAV is dependent on a three
 total flying weight of 2.7 kg (95 ounces); payload: dimensional accelerometer, magnetometer, barometer, and air
camera weighing 700 grams; area = 45.2 dm2 (4.87 speed sensor for feedback.
sq. ft.); WCL = 95 / 4.871.5 = 8.84
The autopilot is controlled by the pilot on the ground through
 Ardupilot APM 2.6, GPS, 3D accelerometer, the radio control system. The autopilot has several modes
barometer, digital compass, magnetometer, airspeed including:
sensor
 Manual - control is by the pilot through the radio
 full duplex telemetry radio system control transmitter
 Spektrum DX8 radio control system  Stabilize - pilot controls the airplane but the autopilot
will recover to level flight if pilot releases the control
 lithium polymer batteries - 4S 4000mAH
sticks
 20 minutes flight time, at 14 m/s, about 17 km range
 Fly-by-Wire - pilot controls the airplane but the
autopilot modifies the commands so the pilot "steers"

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 49
 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015
International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

the aircraft. For example, a constant aileron input will mounted in the aircraft to test performance with the planned
bank the aircraft to a fixed bank angle instead of gross weight.
increasing the bank angle while aileron input is
present. After the aircraft's performance was confirmed to be
 Loiter - circle at a position at a fixed height above satisfactory, the autopilot tuning process began. There are two
ground steps in this procedure. The first part is to configure to autopilot
to fly the aircraft in a stable manner while maintaining a
 Auto - fly the preplanned mission constant altitude. When this is achieved, the pilot can “steer”
the aircraft in a horizontal plane without worrying about
 Return-To-Launch - return to the initial launch
manipulating the throttle and elevator.
location

After the autopilot was tuned for stable flight, it was tuned to
follow a flight plan. The flight characteristics of an aircraft vary
with a number of factors including weight, balance, power, and
airspeed. Performance in level flight is also different from
performance in a banked turn. For a fixed-wing aircraft, making
a turn without significant overshoot or undershoot while
maintaining a constant altitude is the goal of the autopilot
tuning. The aircraft's capabilities, such as its minimum turn
radius, must be considered during the tuning process.

The camera shutter is controlled by the autopilot. The autopilot

is programmed to capture an image at a set distance along a
flight line. This ensures that the image overlap is maintained
even when the ground speed varies as the aircraft is flying at a
constant airspeed in varying wind conditions. The Samsung
camera has a USB interface which allows remote triggering of
its shutter and this is operated by the autopilot through an
electronic relay via a custom USB cable. Information needed to
Figure 2. UAV autopilot, sensor, and radio packages interface this particular camera with the APM autopilot was
gleaned from various Web sources.
The pilot can switch to different autopilot modes using the radio
control transmitter. The pilot can, at any time, switch to Manual
mode and take control of the UAV. All missions are flown with
the UAV in sight of the pilot on the ground so he is in control at
all times.

2.4.3 System Integration

The components of the UAV system must be assembled,
installed and configured before it is operational. The three main
components are the UAV, the ground control system, and the
data processing system.

UAV

The airframe was assembled with modifications made to

accommodate the camera. The aircraft’s fuselage, in stock form,
was not wide enough to house the camera. Structural
modifications were required to mount the camera so it takes Figure 3. UAV Payload – Samsung NX1000 with Carl Zeiss
images in landscape format while in flight. This maximizes the 18mm lens
distance possible between parallel flight lines.
Ground Control System
Next, the electric propulsion, radio control, and autopilot
systems were installed. At this point, the aircraft is capable of
The ground control system consists of an Android pad computer
flight under manual control and flight tests were carried out.
with a 3DR 915 Mhz telemetry radio running Droidplanner
These tests require a pilot who is competent in flying radio
software. This ground control computer can be used to upload
control airplanes.
flight plans to the autopilot and also to monitor the aircraft
remotely while it is in the air. The performance of the UAV is
The flight tests were carried out so the aircraft can be properly monitored in real-time on the pad computer, with parameters
trimmed for level, stable flight and to verify performance. A such as airspeed, elevation, roll, pitch, GPS status, and battery
dummy load of 700 grams, to mimic the camera payload, was condition displayed. The flight plan is shown and the UAV’s
current position is plotted relative to the flight plan. It can also

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 50
 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015
International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

be used to issue commands to the autopilot, such as Return-To-

Launch, while the aircraft is airborne.

Droidplanner software is free and open source

(https://github.com/arthurbenemann/droidplanner/).

Figure 5. Mission Planner

Mission Planner software generates parallel flight-lines which

are flown in order in a zig-zag pattern. This works well if the
aircraft can turn 180o in the distance between adjacent flight-
lines. If the aircraft’s minimum turning diameter is greater than
the line spacing, its turns will be wider than the flight line
spacing and the flight lines will not be flown accurately. This
problem can be solved by extending the flight lines beyond the
area of interest to allow the aircraft to get back on line, or the
lines may be flown in an interleaved pattern with larger
diameter turns.

Our aircraft can follow the zig-zag flight pattern if the

separation between flight-lines is greater than 60 metres. Our
typical missions require flight-line spacings in the range of 20
metres, so an interleaved pattern is used which consists of
flying a series of oval circuits over the project area.

UGL has developed software to automate the calculation of the

flight-line order so that the minimum distance is flown. The
zig-zag flight line files, as generated by Mission Planner, is
processed by the software and it reorders the flight lines so the
required turning minimum turning diameter is achieved. The
software will also try all possible combinations to minimize
flying distance.

Two flight plans are generated for each photo mission with the
flight-lines in one plan at 90⁰  to the flight-lines in the other
plan. The actual plan used will be the one that places any
Figure 4. Ground Control System with 915MHz 3DR radio prevailing wind perpendicular to the flight-lines. Tail winds are
running Droidplanner to be avoided as the aircraft’s increased ground speed requires a
shorter camera exposure to avoid image blur, and the time
Flight Planning between images decreases which may cause the camera to miss
photos. The flight plan is loaded to the autopilot on site after
the wind conditions are assessed.
Mission Planner software is used to plan the UAV flights. It is
free software by Michael Oborne and it allows you to
graphically design flight-lines and generate autopilot command Data Processing
files. This software can also be used to configure the APM
autopilot. Mission Planner is available for free Agisoft PhotoScan Professional software is used to process the
(http://planner.ardupilot.com/). aerial photographs. This software performs photogrammetric
bundle adjustments and produces a Dense Surface Model
(DSM). The process is largely automatic and requires minimal
user intervention.

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 51
 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015
International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

The 3D error at control points compared to GNSS was about

one pixel and the mean distance between both DSM surfaces
was 0.032±0.024 metres [Cryderman, 2014].

The Underhill UAV has been flown in test flights and actual
photography missions and its capabilities have determined from
actual experience. For photogrammetric results of ground pixel
size of 25 millimetres, this UAV can cover an area of
approximately 600 metres by 500 metres, with approximately
23 metres between flight-lines. This will take a flying time of
approximately 20 minutes and approximately 18 kilometres in
distance will be flown.
Figure 6. 3D perspective view of 60 million point DSM
generated from 985 photos in Agisoft PhotoScan These are realistic maximum mission parameters and they are
limited by the energy capacity of the Lithium polymer batteries
powering the UAV and human line-of-sight range. In Canada,
The computer used for processing is equipped with a high UAVs may not be flown beyond the pilot's line-of-sight with
performance graphics processor card. The specialized Graphics the unaided eye.
Processor Units (GPU) are required to process the large amount
of data in reasonable times. 4. FURTHER DEVELOPMENTS
3. RESULTS
Real Time Kinematic (RTK) GPS is becoming a reality for
UAVs. By having a RTK receiver onboard the UAV
The UGL UAV system has been tested in the field and the communicating with a base receiver on the ground, the position
photogrammetric results have been compared with results of of the UAV as it is taking each photograph can be measured to
ground based Global Navigation Satellite System (GNSS) an accuracy of several centimeters. This will provide real
survey. The test was a stockpile survey. Two independent benefits for photogrammetry as it can greatly reduce the amount
flights were flown with 11 independent targeted control points of ground targets required to control the photography (Lapine,
for each flight. The control was created by conventional GNSS 1996). In theory, ground control can be eliminated but it is
survey using Trimble R8's prudent to have a minimal number of ground control points to
guard against blunders and for quality control. As ground
control is a large component of field costs, using RTK for
control is a big step forward.

Figure 7. Study UAV during autonomous flight

Each flight resulted in over 250 photos covering an area 420 Figure 8. GNSS RTK rover for Study UAV. Dual frequency,
metres by 360 metres. The stock pile has a flat top, 120 metres GPS/GLONASS, synchronized camera event recording
above ground. Photographs were taken at a height of 90 metres
above the top with 75% overlaps, forward and side. This The components required for a small UAV RTK system are
worked out to 30 metre spacing between lines with 20 metres now available. There are a number of Original Equipment
between photographs along the line. Each image pixel covered Manufacturer (OEM) RTK GPS boards and antennae which are
approximately 25 millimetres of the ground. small and light enough to be carried by a small UAV.

Dense Surface Models (DSM) were created from each flight. UGL has built a prototype airborne RTK unit with a complete
Photogrammetric bundle adjustments and Dense Surface Model weight of about 170 grams. This includes the basic dual
(DSM) computations of the images were done in an automated frequency GPS/GLONASS GNSS receiver module, antenna,
manner using Agisoft PhotoScan Professional (version 1.0.4). radio for RTCM 3.0 corrections, autopilot interface (for shutter

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 52
 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015
International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

trigger), Arduino based data logger, and battery. The basic

receiver module is 85mm x 22mm x 53mm. The complete
system is easily carried by UGL's UAV. This system is now in 6. CONCLUSIONS
the test phase.

5. REGULATORY CONSIDERATIONS Building your own UAV system for aerial photography/
photogrammetry offers many advantages over buying a turnkey
solution. You can save a lot of money, gain detailed knowledge
UAV flights by non-commercial and non-military users have of your system so you can service it yourself or upgrade it in
increased dramatically in the last few years and governments the future, and not be tied to a specific vendor. However, to
are scrambling to regulate UAV use. The regulations are aimed reap these advantages, you must understand an array of
mainly at commercial users, and in Canada, the regulatory technologies and be able to integrate them into a functioning
body, Transport Canada, has introduced regulations which system.
govern the commercial use of UAVs. These regulations are
aimed at keeping UAVs from endangering people and property
In the field of fixed-wing UAVs, there is the choice of flying
both on the ground and in the air (Transport Canada, November
wing or conventional airframe with fuselage and tail. We chose
2014).
to implement a conventional airframe despite evidence that a
flying wing configuration is more efficient (Brucas, 2013). Our
In Canada, commercial UAVs must be operated within line-of- experience has shown that the main disadvantage of a
sight of the pilot. This limits the distance a small UAV may be conventional airframe, aerodynamic efficiency and endurance,
flown from the pilot to 400 metres to 500 metres. The pilot is not an issue due to regulatory limitations in Canada which
must be in control of the UAV at all times. The pilot will be limits flights to line-of-sight. The line-of-sight limitation
monitoring the flight when the autopilot is flying the UAV and negates the requirement for extreme endurance. Meanwhile, the
be ready to take control. The pilot must also be knowledgeable big disadvantage of the flying wing, high stall speed, is avoided
about the applicable laws, full scale flight procedures, and flight so launching and recovery do not require additional complex
systems. Additionally, the UAV must have $100,000 of systems such as catapults and parachutes.
liability insurance (Transport Canada, August 2014).
In the early part of the last century, land surveying utilized low-
Transport Canada requires UAV operators obtain a Special technology tools and required a high level of user involvement,
Flight Operations Certificate (SFOC) for commercial flights. both physically and mentally. That meant that surveyors out in
Operators apply for SFOCs by submitting a plan which the field were self-sufficient and could be away in the
describes all aspects of the flight operations and demonstrates wilderness for months. By the end of the last century, the level
that they have the ability and systems in place to conduct safe of technology had risen substantially while the user effort
UAV operations. The company’s flight operations include required had dropped, but the two were still relatively in
training, maintenance, procedures, and documentation. balance. Today, survey technology, in the form of UAVs and
Approval of the plan and issuance of a SFOC can take several photogrammetry, has drastically upped the technology level
weeks. while relieving the surveyor of physical and mental efforts.

Under specific conditions, there are exemptions from this The UAV mapping technology when viewed as a black-box
requirement (Transport Canada, November 27, 2014). In solution has many problems aside from buy-in costs. The user is
general, the exemptions apply to UAVs not heavier than 25 kg shielded from the technology and is told that it is easy to use.
operating in uncontrolled airspace (Class G) more than 5 miles This is true if everything is working perfectly. The individual
from any aerodrome or built up area. There are other components – computers, camera, radios, and aircraft – are not
conditions but the exemptions are aimed at UAV operations in leading edge, and in fact, they are quite common these days.
airspace where the risk to people, property, and aircraft is low. However, because they must work together, the probability for
a system failure becomes more significant.
Transport Canada is still developing the UAV regulations and it
has indicated that the current regulations for UAVs weighing 25 This is particularly true when the weakest link in the chain, the
kg or less are a temporary measure and that changes are UAV itself, does its work in the open air, subject to varying
proposed for 2016 (Transport Canada, May 2015). These physical conditions. The UAV, while controlled by the
proposed changes will address aircraft registration, personnel autopilot, is operating at its highest risk level and is vulnerable
training, and flight rules. to damage. The risk is controlled to acceptable levels when the
flight is monitored by a competent pilot who is experienced in
One regulatory area that the government may touch and would flying radio-controlled aircraft and is ready to take over flight
affect the UAV DIYer is certification. Full scale aircraft must control. If the pilot is merely monitoring and relying on
be certified to be airworthy and have maintenance procedures to programmed routines to fly the aircraft back to the launch point
ensure its continuing airworthiness. As a DIYer, it is important and auto-land, then the probability of aircraft damage increases
that documentation for all components of the UAV is kept and significantly.
logs for the flights and maintenance of the UAV are kept. It
may be necessary to prove to a regulatory body that your UAV While the UAV mapping technology is being treated as a black-
is airworthy and safe to fly. On the other hand, the DIYer box solution that is fool-proof, it is evident that it is not without
should be knowledgeable about the aircraft and be capable of risk. When UAVs are used in its logical environment, mapping
maintaining it. uninhabited areas away from urban areas, then reliability
becomes an issue. Being able to trouble-shoot and fix system

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 53
 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XL-1/W4, 2015
International Conference on Unmanned Aerial Vehicles in Geomatics, 30 Aug–02 Sep 2015, Toronto, Canada

problems in a timely manner with minimum access to service International Archives of the Photogrammetry, Remote Sensing
centres is necessary. This is where a DIY UAV system operated and Spatial Information Sciences, Vol. XXXVIII-4/W19
by its builders has a distinctive advantage over a turnkey
system.
Lapine, L.A., 1996. Airborne kinematic GPS positioning for
photogrammetry: The determination of the camera exposure
UAVs for aerial photography have been promoted as the new
way to map large areas efficiently. Tests have shown that to be station.
true. The cost of the technology is comparable to that of GNSS http://www.ngs.noaa.gov/PUBS_LIB/AirborneKinematicGPSP
survey and the results are comparable with much greater ositioningforPhotogrammetry.pdf
resolution. This is a major leap forward.
Mészáros, J., 2011. Aerial Surveying UAV Based on Open-
However, there are risks in UAV technology that are not Source Hardware and Software. International Archives of the
inherent in the GNSS technology. When these risks are factored Photogrammetry, Remote Sensing and Spatial Information
in, the advantages of UAVs are not as great. This is particularly Sciences, Vol. XXXVII-1/C22
true with the turnkey UAV packages operated by people with
minimal training. Morin, Brit, 2013. What Is the Maker Movement and Why
Should You Care? http://www.huffingtonpost.com/brit-
Building your own UAV system reduces these risks morin/what-is-the-maker-movemen_b_3201977.html
considerably. Coupled with a pilot who is able to fly the UAV
to a safe landing when the autopilot fails, an UAV system
becomes very competitive. This approach differs greatly from Reynolds, Francis, 1989. Model Design & Technical Stuff:
the turnkey system approach where minimum system Wing Cube Loading (WCL)
knowledge is required. http://www.theampeer.org/CWL/reynolds.htm

The increasing numbers of UAVs, both hobbyist and Sollenberger, Roger, 2014. From The Economist, Chris
commercially operated, has governments scrambling to regulate Anderson on Drones: A Short History, Long Future
their use. In Canada, Transport Canada is the regulatory body. http://3drobotics.com/2014/09/economist-chris-anderson-
Where UAV flights place people, property, or full scale aircraft drones-short-history-long-future-long-tail/
at risk, the operator must receive from Transport Canada a
Special Flight Operations Certificate (SFOC). In order to
Transport Canada, May 2015. Notice of Proposed Amendment
receive an SFOC, the operator must show that it can safely
operate the UAV. Knowledge of flight operations and systems (NPA): Unmanned Air Vehicles, CARAC ACTIVITY
is required. REPORTING NOTICE #2015-12

Using the UAV technology effectively for mapping requires Transport Canada, November 27, 2014. AC 600-004 - Advisory
special skills. The move towards “black boxes” for surveying Circular: Guidance Material for Operating Unmanned Air
has become the norm. UAVs may become “black boxes” in the Vehicle System under an Exemption
future but it is not yet there. However, those who understand
and build their own systems will be able to deploy them
effectively and economically. Transport Canada, August 2014. TP 15263E - Knowledge
Requirements for Pilots of Unmanned Air Vehicle Systems
REFERENCES UAV 25 kg or less, Operating within Visual Line of Sight, First
Edition
Brucas, D., Suziedelyte-Visockiene, J., Ragauskas, U.,
Berteska, E., Rudinskas, D., 2013. Implementation and Testing Transport Canada, November 2014. SI 623-001 - Staff
of Low Cost UAV Platform for Orthophoto Imaging. Instruction – Review and Processing of an Application for a
International Archives of the Photogrammetry, Remote Sensing Special Flight Operations Certificate for the Operation of an
and Spatial Information Sciences, Vol. XL-1/W2, 2013 UAV- Unmanned Air Vehicle (UAV) System
g2013

Coyle, Thomas, 2015. DIY Drones at 64,000 members! Wired Staff, 2012. Wired Editor-in-Chief Chris Anderson Steps
http://diydrones.com/profiles/blogs/diy-drones-at-64-000- Down to Run Robotics Startup
members http://www.wired.com/2012/11/wired-editor-in-chief-chris-
anderson-steps-down/

Cryderman, C., Mah, B., Shufletoski, A., 2014. Evaluation of

UAV Photogrammetric Accuracy for Mapping and Earthworks
Computations. GEOMATICA, Vol. 68, No. 4, 2014, pp. 259-
271

Karakis, S., Sefercik, U. G., Bayik, C., 2011. Data Acquisition

Through the Model Aircraft for Mapping Services.

This contribution has been peer-reviewed.

doi:10.5194/isprsarchives-XL-1-W4-47-2015 54