Flight Analysis

Flight Analysis program analyses flight logs created by GPS logging software such as GPS_LOG WinCE. It accepts files in International Gliding Commission or GPS_LOG program family formats. Files are analysed to provide thermalling and performance statistics. Tasks can be evaluated as well. Files with gps and igc extensions can be associated with Flight Analysis in the associations tab of settings.

Analysis parameters set in the "Settings" tabs are used as default values. Values set on the main screen are temporary. "Ignore reversals" checkbox controls whether the program attempts to take into account reversal of circling direction while thermaling or not. If there are few points logged per circle, you should check this box. "Correct for sampling" box controls whether thermalling speed is corrected for the difference between a circle and a polygon. This box should also be checked if there are few points around a circle. You should not expect good analysis results if there are fewer than 5 points around a circle. Lower the threshold if your sampling period is long. 

If you suspect that the program is having troubles detecting landing, check the "Disable high winds" checkbox in the "Triggers" tab of settings. This will determine landing based only on ground speed (this can be very small in a wave flight when flying upwind causing false landing indication and analysis termination).

Flight release point is established by Flight Analysis either by looking for thermalling activity or for average sink rate greater than threshold. you can modify detection parameters in "Triggers" tab of settings.

"Final Glide" in this case is the period from last thermal to landing. If you circle to loose altitude, this may be 
considered a thermal.

Flight analysis also displays flight barogram and trace of a flight. If your IGC file contains valid task declaration, you can display traces centered around turnpoints.

If you set time zone offset in settings, Flight Analysis displays "(lcl)" indicator when showing flight date or time information. Time recorded in analysed file is assumed to be GMT.

Upon Installation a shortcut to the program is created in "Programs" folder on the Start Menu. Program itself is installed to "Program Files\Flight Analysis" directory.

Files with multiple flights

Flight Analysis is designed to expect one flight per file. However you can specify multi-flight files in file options. Using the program in that fashion requires disabling track cache, thus it will run slower. In addition the task evaluation and flight analysis modules are basically independent components that share track plotting capabilities. If you evaluate task on one flight, but analyse another, you will get track map plots that you do not expect. Last flight acted upon is plotted. You select which flight is evaluated or analysed by specifying time when you are asked for it by the program. NOTE: You can switch memory cache off after a file is loaded, but turning it back on does not take effect until a different file is opened.

Viewing flights

Flight Analysis displays a "main flight view" and views around task turnpoints. What you see the first time you see the main flight view depends on whether your file contains a task or not. If it does Flight Analysis displays an area that contains both, flight and task. The same will happen if you load a task after flight file but before analysing the flight or evaluate it against a flight file. You can pan and zoom main flight view. Change the scale of the drawing using the "+" and "-" buttons on the right bottom part of the display. Pan the view by dragging stylus on the screen (minimum 10 pixels). Coordinates of top left and bottom right corners of what you see are displayed above the "map".

If task with turnpoints is available, you see a two arrow spin control in top left corner that allows you to display views of turnpoints. Panning turnpoint views is not possible. Turnpoint views are centered on turnpoint goal coordinates (see task file format.)

Flight distances

You can estimate distance flown by establishing points of interest by clicking on the "main flight view". Cumulative distance between clicks is shown above top left of the flight display. Clear this distance by clicking on the distance number. You can pan and zoom the display between clicks.

Evaluating tasks

Setting up a task for evaluation is reasonably straightforward. Each turnpoint can be set up independently if the "All alike" checkbox is clear. For line gates and turnpoints with sectors you can set up directions. For gates this is direction perpendicular to gate line pointing in flight direction, for turnpoints it is direction of the bisector pointing into the sector. Directions can be reset at any point with a [Reset Dir] button. Setting sector radius to zero means that there is no limit on distance from turnpoint within a sector. 

Setting top of start gate to zero disables checking for altitude, otherwise valid start has to be below supplied value which is interpreted as MSL pressure altitude. For purposes of task evaluation only pressure altitude is used and reported. Pressure altitude is corrected before takeoff to correspond to GPS altitude (similarly to setting altimeter to field elevation).

Task distances reported depend on whether "Maximise distance" checkbox is checked and turnpoints marked (individually) with "TA" as turn area turnpoint. For turnpoints not marked as TA distance is measured from the turnpoint itself and a small cross marks the first point within observation zone when flight track is displayed. For TA marked turnpoints, distance is measured from a point that maximises task distance and that point is marked with a small cross on track display. For gates, it is always the last or first point within observation zone that is used for distance and time.

Start time is given by the last crossing of a start gate prior to reaching first turnpoint. For the rare cases when task is restarted after first turnpoint was reached, you can set up flight analysis to ask for the time after which to look for start. This option appears on the "Files, Maps, Tasks" tab of options.

Once task is evaluated displaying track around a turnpoint shows track within limited time around "made" turnpoints, and all trace past last credited turnpoint on ones that were missed. The time span is set on the "Files, Maps, Tasks" tab of options.

Flight Analysis supports sector observation zones with minimum sector radius as for Assigned Area Tasks. This definition is mutually exclusive with observation zone having a cylinder and with all turnpoint observation zones being alike. The same edit box is used to define minimum sector radius and cylinder radius. It is labeled appropriately for both operations. It is also not visible unless checkbox indicating a cylinder or minimum radius is marked.

Program also supports task definitions where the goal turnpoint is not the same as the task definition turnpoint, as in AAT. Currently there is no way to enter goal point coordinates from within Flight Analysis, however, program can read task definition files generated manually or by other programs such as GPS_LOG WinCE which contain that information. Format of such files is described below. In the display task is drawn goal point to goal point when information is available.

Entering tasks into Flight Analysis

There are two ways of entering tasks for evaluation into Flight Analysis. When an IGC file is opened it is scanned for task declaration up to the first position fix (B) record. Task from the last declaration found is used for evaluation. If a task is not found current task remains. Whether a task declared past the first position fix record is used depends on whether file is first used to analyse flight or to evaluate task. If a task is found during flight analysis it is entered as current task. If a task is evaluated first, and memory cache is used, analysing that flight will not replace current task. A task can also be entered by loading a task file from File menu. Task files typically have TSK extension. Once you define a task on the task summary screen, you can save it with all details to a file for future use. Task files are simple text files and can be created using text editor. 

Task file format 

Flight Analysis supports only one task per file, Flight Display and GPS_LOG WinCE support multiple tasks per file. A task on file looks typically as follows :

CGC - takeoff site,41.431950,0,0,88.245834,0,0 
CGC - landing site,41.431950,0,0,88.245834,0,0 

The "zones" and landing and takeoff sites are optional. Detailed explanation follows: 

File is coma delimited. Comas HAVE to follow numbers with no spaces. 

Line 1: /*TASK*/ - delimiter for tasks 
Line 2: name - unique name given to a task, cannot be duplicated within the same file 
Line 3: color - for use of Flight Display only 
Line 4: nTskP, nExtra, nZones 
                - nTskP is the number of task points (gates and turnpoints), 
                - nExtra number of extra takeof and landing points. Can be 0,1,2. 
                        There can be no landing site if there is no takeoff site. 
                        This parameter does not have to be included if there are no zones, 
                        nor takeoff/landing sites. 
                - nZones number of observation zones. has to be nTskP+nExtra if present 
Lines 5-x: name,latDeg,latMin,latSec,lonDeg,lonMin,lonSec,elevation 
        - elevation is in feet and is optional. 
        - Longitude is positive in the West. To indicate East make ALL lonXXX fields negative or zero.
        - Latitude is positive in the North. To indicate South make ALL latXXX fields negative or zero. 

Line x+1: \*zones*\ - delimiter 
Line x+2: nZones - number of observation zones, the same as in line 4. 
Lines x+3 - y 
        isGate 0 or 1,
        isTurnpoint 0 or 1 or 3; 3 means that this is a checkpoint. Flight Analysis eliminates checkpoints
        hasCylinder 0 or 1, 
        hasSector 0 or 1, 
        cylinderRadius in km, 
        sectorRadius in km, 
        isTurnArea 0 or 1 indicates that distance can be maximised at this turnpoint, 
        sectorAngle full angle in degrees, 
        sectorDirection sector bisector direction (into the sector), or flight direction for a gate. 
        minimum sector radius in km;  requires hasSector to be 1 and hasCylinder to be 0
        turnpoint goal longitude,
        turnpoint goal latitude,
        turnpoint goal elevation in feet (in meters if terminated with M e.g.: 234M )
Line y+1 
        startGateTop in feet MSL, startLineLength in km, finishLineLength in km, startHasLine 0 or 1, finishHasLine 0 or 1