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This is a pair of small Windows utility utilities that analyzes a run and calculates the appropriate recalibration for your Garmin Foot Pod. This software was tested with a Garmin 310XT and 210, but should work with any Garmin that works with the footpod. The software is available as a GUI and a Command Line Interface. Note, this is open source and released under [http://www.gnu.org/licenses/gpl.html GPL].
==How does it work?==
===Flaws in the approach===
The biggest flaw in the approach is that it relies on the GPS signal, and GPS is not that accurate itself. If you do not have a GPS signal, such as a treadmill run, then there is no calibration possible and this utility will show that none is neededno calibration can be automatically performed. That is because the Garmin recorded data is based on the footpod, so it's calibrating the footpod against itself.
===Getting the best data===
===Is there a better way?===
A better approach would be to run a known distance, either on a track or using a known course and calibrate against that known value. This utility does not do that yet, but it is a planned upgrade. It will require moving to a nicer The GUI as wellversion allows this type of adjustment.
==Installation==
* Download the command line executable from http://fellrnr.com//Utilities/CalibrateFootPod/ParseTCXGarminFootpodCalibrationCLI.exe* Download the GUI executable from http://fellrnr.com//Utilities/CalibrateFootPod/GarminFootpodCalibration.exe
* Check the executable for viruses (trust no one!)
This utility does not require a special calibration run to gather data. Any run with your Garmin 310XT and Foot Pod enabled will provide the data needed. Running at a steady pace will provide good data. If you take walking breaks, this will tend to produce a lot of variability.
==Command Line Version=====Garmin Training Center===
* Transfer the record of the run to Garmin Training Center.
* Export the record of the run from Garmin Training Center as a 'TCX' file.
* A command window should open and print out a lot of data. At the end you should have a line that says "Multiply your current calibration factor by N" where N is the scaling factor.
* On your Garmin, multiply your current calibration factor by this new scale. So if your scale is currently 990 and the calibration factor is 0.94255403, the new scale will be 933.
===Garmin Ant Agent===
* Transfer the record of the run using the Ant Agent.
* Run the executable ParseTCX.exe with no parameters. The utility will try to find the store of TCX files that the Ant Agent uses.
* A command window should open and print out a scaling factor for each file it finds.
* On your Garmin, multiply your current calibration factor by one of the new scaling factors. So if your scale is currently 990 and the calibration factor is 0.94255403, the new scale will be 933.
==Consistency=Example Output=The utility looks at how consist the footpod and the GPS are (standard deviation). This is to give you a sense of how useful the scaling factor change would be. This consistency rating is provisional, and is based on the following scale.* stddev < 0.02 = "very good"* stddev < 0.05 = "good"* stddev < 0.075 = "okay"* stddev < 0.1 = "poor"* stddev < 0.2 = "very poor"* stddev >= 0.2 = "appalling"Let me know if you have a better suggestion for the scale. ==Example Output=====All Ant Agent Files====
<pre>
Version 2.02011-0102-1303-083545063813.TCX calibration factor adjustment 0.9998, Consistency is appalling (stddev 0.2378)Looks like data from cycling not running2011-0102-1404-085610071012.TCX filtered calibration factor adjustment 0.9909, Consistency is very poor 9807 (stddev 0.13220964)2011-0102-1504-090651071012.TCX raw calibration factor adjustment 0.7886, Consistency is appalling 8722 (stddev 0.26362023)2011-0102-1605-072027075131.TCX filtered calibration factor adjustment 0.9816, Consistency is okay 9856 (stddev 0.06710945)2011-0102-1705-083519075131.TCX raw calibration factor adjustment 0.9642, Consistency is poor 9811 (stddev 0.09921393)2011-0102-1806-080330115537.TCX No usable Looks like data was found infrom cycling not running2011-0102-1907-075748065800.TCX filtered calibration factor adjustment 0.8927, Consistency is appalling 9855 (stddev 0.2764067)2011-0102-2007-083432065800.TCX No usable data was found inraw calibration factor adjustment 0.983 (stddev 0.0907)Press return to continePress return to contine
</pre>
====Single File====
<pre>
Version 2.0
Per Lap Scaling
===============
lap average scale 0.99779755lap average scale 0.99549924lap average scale 0.98539866lap average scale 0.98369797lap average scale 0.98929755lap average scale 0.9976lap average scale 0.9974lap average scale 0.9877lap average scale 1.0025lap average scale 0.99lap average scale 0.9705lap average scale 0.983lap average scale 0.9553lap average scale 0.9778lap average scale 0.9967lap average scale 1.002lap average scale 0.9606lap average scale 0.9907lap average scale 0.9837lap average scale 0.9929lap average scale 0.9972lap average scale 0.9843
Details
=======
Filtered Average scale 0.99099855, 9998.08575455%Consistency very poor Standard Deviation scale 0.1322067, 136.22096979% Scale+stddev 1.12310524, 112105.3124% Scale-stddev 0.85879185, 91.85%Raw Average scale 0.983, 98.873044%Average Standard Deviation scale (per lap) 0.99020907, 9.0679% Scale+stddev 1.0737, 107.37% Scale-stddev 0.8924, 9989.023424%
Calibration Instructions
========================
Multiply your current calibration factor by 0.9909983
Press return to continecontinue
</pre>
==Support==
==Change log==
* V2.0
** Major refactoring and the creation of a GUI version
* V1.2
** Fix a crash on TCX files that had a lap with no track points
** Add more defensive coding
** Many thanks to Dan M. for finding this bug!
** Documentation for 1.2 can be found at http://fellrnr.com/mediawiki/index.php?title=Garmin_Foot_Pod_Calibration&oldid=765
* V1.1
** Fix bug in XML parsing (Use of XML node name rather than local name)