INTREPID User Manual Survey distance calculation (T10) 1
Library | Help | Top | Back |
Survey distance calculation (T10) Top
The Survey Distance Calculator calculates the total distance travelled in one or more
surveys, based on the flight data recorded. You can use the results for accounting
purposes.
You can choose which parts of the surveys to include in the calculation according to
survey, flight and traverse line numbers. INTREPID will graphically display flight
paths of the selected data if required.
You can choose whether to calculate the distance accurately from point to point or
assume that each traverse line is approximately straight and use the end points of
the traverse lines.
If you are processing unprojected data (data with geographical coordinates– latitude
and longitude), you can specify the average height of the survey above the datum for
the purposes of the calculation.
Projections and measurement units
If the data is projected, INTREPID assumes that it has already been transformed
into a suitable coordinate system with distances in metres. It therefore does not
transform the input data and calculates distances by simply integrating along each
individual traverse line, The resultant distances will naturally depend on the
projection used.
If the data is unprojected, INTREPID assumes that its location data has geographic
coordinates (latitude and longitude) relative to the AGD84 datum. INTREPID
calculates all distances along the surface of the AGD84 ellipsoid using Robbin's
formula. INTREPID allows for a nominal height of the survey area above the
datum.1
1. The current version of INTREPID can only calculate survey distance for unprojected
data in geographic coordinates relative to the AGD84 datum. If your unprojected data has
a different datum, you must transform it to AGD84 before using this tool. INTREPID
cannot calculate survey distance for unprojected data in metres (i.e., data with projection
RAW). If you regularly process unprojected data which is 'raw' or has a different datum, we
can customise the tool for you. Please contact our technical support service for further
information.
Library | Help | Top © 2006 Intrepid Geophysics | Back |
INTREPID User Manual Survey distance calculation (T10) 2
Library | Help | Top | Back |
Using the Survey Distance Calculator tool
>> To use the Survey Distance Calculator with the INTREPID graphic user
interface
1 From the Utility menu in the Project Manager, choose Survey Distance
Calculator, or use the command sdist.exe. INTREPID displays the Survey
Distance Calculator tool.
2 If you have previously prepared file specifications and parameter settings for
Survey Distance Calculator, load the corresponding task specification file using
Load Options from the File menu. (See "Specifying input and output files" for
information about specifying files). If all of the specifications are correct in this
file, go to step 9. If you wish to modify any settings, carry out the following steps
as required.
3 Specify the dataset to be processed. Use Open Input Dataset from the File menu.
(See "Specifying input and output files" for information about specifying files).
4 Specify the report output file if required. Use Specify Output Report from the
File menu. (See "Specifying input and output files" for information about
specifying files).
5 Specify the traverse lines you wish to include in the calculation. Choose Select
Lines from the Options menu and complete the Traverse Line Ranges dialog box.
(See "Selecting the traverse lines to include in the calculation" for details).
6 Select whether to perform the calculation in Accurate mode (point to point
measurements) or Standard mode (whole line measurements). Use Accurate
from the Options menu (See "Specifying the precision of the distance
calculations" for details).
7 Select whether to display the flight paths of the traverse lines as they are
processed. Use Plot Flight Path from the Options menu. (See "Graphic display of
the flight paths calculated" for details).
8 If you are processing unprojected data, specify the average height of the survey
above the datum. Use Altitude from the Altitude menu. (See "Specifying the
average survey height" for details).
9 When you have made specifications according to your requirements, choose Apply.
INTREPID will perform the calculation.
10 If you wish to record the specifications for this process in a task specification
(.job) file in order to repeat a similar task later or for some other reason, use
Save Options from the File menu. (See "Displaying options and using task
specification files" for detailed instructions.)
Library | Help | Top © 2006 Intrepid Geophysics | Back |
INTREPID User Manual Survey distance calculation (T10) 3
Library | Help | Top | Back |
11 If you wish to repeat the process, repeat steps 2–10, varying the specifications as
required.
12 To exit from Survey Distance Calculator, choose Quit from the File menu.
___
To view the current set of specifications choose Show from the Survey Distance
Calculator window. INTREPID displays them in a separate window. See
"Displaying options and using task specification files" for details and an example of a
set of specifications.
You can view Help information by choosing options from the Help menu (See "Help").
You can execute Survey Distance Calculator as a batch task using a task specification
(.job) file that you have previously prepared. See "Displaying options and using
task specification files" for details.
Specifying input and output files
To use Survey Distance Calculator, you will need to specify:
• The line dataset whose distance is to be calculated,
• The file name for the report if you wish to save it.
Choose the options as required from the File menu.
In each case INTREPID displays an Open dialog box. Use the directory and file
selector to locate the file you require. (See "Specifying input and output files" in
Introduction to INTREPID (R02) for information about specifying files).
Vector dataset notes: INTREPID will identify fields for the process from the
dataset aliases. The dataset must have the following aliases identifying appropriate
fields.
Alias Field
X X coordinate (location)
Y Y coordinate (location)
LineNumber Line number field
FlightNumber Flight number field
See "Vector dataset field aliases" in INTREPID file and directory structure (R05) for
more information about aliases.
Open Input Dataset Use this to specify the line dataset for the data you wish to
process. INTREPID uses the dataset aliases to determine the field names for the
X,Y (location) data (See "Vector dataset field aliases" in INTREPID file and
directory structure (R05) for details).
Library | Help | Top © 2006 Intrepid Geophysics | Back |
INTREPID User Manual Survey distance calculation (T10) 4
Library | Help | Top | Back |
Specify Output Report INTREPID creates a report of the calculation. You can
instruct INTREPID to save the report by specifying a file name for the report.
(See "Survey Distance Calculator reports" for more information about the report).
Load Options If you wish to use an existing task specification file to specify the
survey distance calculation, use this menu option to specify the task specification
file required. INTREPID will load the file and use its contents to set all of the
parameters for the survey distance calculation. (See "Displaying options and
using task specification files" for more information ).
Save Options If you wish to save the current Survey Distance Calculator file
specifications and parameter settings as a task specification file, use this menu
option to specify the filename and save the file. (See "Displaying options and
using task specification files" for more information).
Selecting the traverse lines to include in the calculation
You can select traverse lines to be included in the calculation by specifying ranges of
survey and/or flight and/or traverse line numbers. You can only specify one range at
each level.
>> To select traverse lines for inclusion in the calculation,
1 Choose Select lines from the Options menu.
INTREPID displays the Traverse Line Ranges dialog box.
2 Complete the dialog box with the lower and upper survey/flight/traverse line
number limits, then choose OK. The default values are 0 and 999999 at all levels.
INTREPID will restrict the calculation to the traverse lines whose identifications
fall within the ranges you specified. It displays a tick against Select Lines in the
Options menu.
>> To disable Select Lines and include the whole dataset in the calculation
Choose Select Lines from the Options menu again when it has a tick against it.
INTREPID will turn off the Select Lines option and remove the tick.
Library | Help | Top © 2006 Intrepid Geophysics | Back |
INTREPID User Manual Survey distance calculation (T10) 5
Library | Help | Top | Back |
Graphic display of the flight paths calculated
INTREPID can display graphically the flight paths of the traverse lines included in
the calculation. The display appears in the Survey Distance Calculator window.
The Plot Flight Path option in the Options menu indicates whether INTREPID
displays the flight paths. You can turn it on and off by choosing it. If it is turned on
(showing a tick), INTREPID displays the flight paths. If it is turned off (not showing
a tick), INTREPID will not display the flight paths.
Survey Distance Calculator reports
The Survey Distance Calculator displays a report of its results in a scrollable report
window. You can dismiss the report window by choosing Done in the report window.
The window will reappear if another message is sent to it. You can save the report as
an ASCII file if required. (See "Specifying input and output files" for instructions).
Library | Help | Top © 2006 Intrepid Geophysics | Back |
INTREPID User Manual Survey distance calculation (T10) 6
Library | Help | Top | Back |
Specifying the precision of the distance calculations
You can choose whether to
• Calculate the distance accurately from point to point along the traverse lines (i.e.,
calculate distances between each successive pair of X, Y coordinates and sum
these distances),
• Assume that each traverse line is approximately straight and use the end points
of the traverse line. (If data gaps exist in the traverse line, INTREPID
approximates each continuously defined section by a straight line. In other words,
INTREPID ignores data gaps.)
___
The Accurate option in the Options menu indicates which method INTREPID will
use. You can turn it on and off by choosing it. If it is turned on (showing a tick),
INTREPID will use the point to point measurement method. If it is turned off (not
showing a tick), INTREPID will use the whole traverse line measurement method.
Specifying the average survey height
If you are processing unprojected data, distances will differ slightly at different
heights. You can specify the average height of the survey above the datum.
>> To specify the average survey height
Choose Altitude from the Altitude menu.
INTREPID displays the Average Survey Height dialog box.
Specify the average survey height above the datum (above sea-level) and choose OK.
INTREPID will use this parameter in the calculation.
Note: Even though the menu and dialog box refer to Altitude, INTREPID requires
and uses the average survey height above the datum. Future versions of INTREPID
will correct this discrepancy.
Apply
When you choose Apply, INTREPID performs the survey distance calculation,
displaying the flight paths and/or saving the report file if required.
Library | Help | Top © 2006 Intrepid Geophysics | Back |
INTREPID User Manual Survey distance calculation (T10) 7
Library | Help | Top | Back |
Help
You can use the help menu to display help text on the topics shown in the menu
illustration below.
Exit
To exit from Survey Distance Calculator choose Quit from the File menu.
Displaying options and using task specification files
Displaying options
>> To display the current task specifications
Choose Show from the Survey Distance Calculator window. INTREPID displays the
current file specifications and parameter settings in a report window.
Using task specification files
You can store sets of specifications for Survey Distance Calculator in task
specification (.job) files.
>> To create a task specification file with the Survey Distance Calculator tool
1 Specify all files and parameters.
2 If possible, execute the task (choose Apply) to ensure that it will work.
3 Choose Save Options from the File menu. Specify a task specification file
(INTREPID will add the extension .job) INTREPID will create the file with the
current parameters.
For full instructions on creating and editing task specification files see "INTREPID
task specification (.job) files (R06)" files.
>> To use a task specification file in an interactive Survey Distance
Calculator session
Load the task specification (.job) file (File menu, Load Options), modify any settings
as required, then choose Apply.
>> To use a task specification file for a batch mode Survey Distance
Calculator task
1 Type the command sdist.exe with the switch -batch followed by the name (and
path if necessary) of the task specification file.
For example, if you had a task specification file called surv_cal.job in the current
directory you would use the command
sdist.exe -batch surv_cal.job
Library | Help | Top © 2006 Intrepid Geophysics | Back |
INTREPID User Manual Survey distance calculation (T10) 8
Library | Help | Top | Back |
Task specification file example
Here is an example of an Survey Distance Calculator task specification file.
Process Begin
Name = surveyDistance
DataBase = /disk1/surveys/p538/SEC/
Parameters Begin
ReportFile = ""
SelectLines = No
PlotFlightPath = No
Accurate = Yes
Altitude = 0.00
MinSurveyNumber = 0
MaxSurveyNumber = 999999
MinFlightNumber = 0
MaxFlightNumber = 999999
MinLineNumber = 0
MaxLineNumber = 999999
Parameters End
Process End
Library | Help | Top © 2006 Intrepid Geophysics | Back |
