There appears to be a few knickers in a twist over this issue. We should be pleased, although in my case sometimes confused, when the GPS-TC technical committee is prepared to publicly discuss their deliberations on the efficacy of various GPS units. It's disappointing that this openness has lead to some bitterness and recrimination. It might be worthwhile looking at the context of how the current rules regarding GPS units have been established.
GPSTC (based in Australia) and GP3S (based in Europe) are volunteer organisations and web sites that were established to facilitate the downloading, analysis and comparison of GPS tracks across a number of divisions (2sec, 5X10, hour, alpha, Nm, distance). These web sites provide a means to compare results of different windsurfers from different locations at different times. In order to create a level playing field, both organisations have developed rules for GPS devices that are approved for posting result. The rules from both organisations are copied below. They are the result of testing and analysis by the volunteer technical committees of both organisations. Its not surprising they are remarkably similar which would suggest a consistent approach by both organisations.
GPS Team Challenge (GPS-TC) The following GPS's are considered valid for the purposes of the challenge (most preferable at the top, least preferable at the bottom):
- Thingsee One GPS3 edition
- GW-52NAVI GT-31 (uses 1 sec recording intervals)
- NAVI GT-11 (uses 1 sec recording intervals)
- Canmore GP-102
Check out discussions on Seabreeze for more information or to get help from the GPSTC community. Other GPS units can be approved by the technical advisers of the challenge. All software should be set to "Doppler if available" for all categories.
Approved GPS devices for posting on GPS-TC:
We have some concerns about the accuracy, and therefore fairness of the use of the GPS-Logit app for posting in the GPS-TC using current model Android Phones. Hence so much testing and comparison as you can see in other Seabreeze threads.
The current policy of GPS-TC is that GT-31 should be used for posting Doppler based data (D) by individuals and team members vying for the top positions.
The GW-52 is also approved for use in the same way using 5hz logging*.
GPS-TC also allows the legacy pre GT-31 GPS (mainly Garmin) that only produced speed results from positional data (T), but only for those sailors not in the category mentioned above.
The Canmore has been approved for use as it sits somewhere in between those already mentioned. It has the potential accuracy of the GT-31 as it is a Doppler based device, but it has very limited verifiability. If you are posting results that are counted in the team challenge in a competitive team you should inspect the results closely in a stand alone analysis program (GPS-Results/GPSAR-Pro/RealSpeed) for unusual results and errors. Preferably, team captains to the team 'tech guru' should help with this, and if there is any doubt the files should be sent to one of the GPS-TC technical advisors for a second or third opinion.
* The best mode for accuracy in the GW-52 is setting it to 5hz logging. The 1hz setting should be avoided as it can introduce aliasing issues as the data does not appear to be processed in the same way as in the GT-31. 'Smart logging' should not be used for posting. (based on recommendation by Manfred Fuchs as a result of his testing). Some issues with processing Alphas from 5hz GW-52 data have also been observed with the current version of RealSpeed only. GPSAR-Pro, GPS-Results and KA-72 seem to produce accurate results.
Sessions for the teams will be submitted by either the team captain, or the individual user. Session results need to be supplied monthly, though every session in a month can be submitted, and the computer data base will calculate which is the best speed to be recorded for the month.. Each team score will be rank ordered against other teams and a score awarded in each category from lowest to highest. eg. if there are 16 teams in a given category that have submitted a time these will be awarded points according to rank ordering. from a 1 for best time/speed, to 16 for worst. This is done in each category, with the team having the lowest points for the month, being the leading team for the month.
GPS-Speedsurfing (GP3S) Since the introduction of GPS-Speedsurfing.com we have used several approved GPS-Devices, in recent years we switched over to Doppler supported devices, first introduced with the GT-11 and later the GT-31. Sadly the production of the GT-31 has reached the “End of Life” status, so the availability will be very limited in the next months.
Our Technology team has been working on other GPS-Devices in the last months, and we have been working on several parallel tracks. The first track is focused on the development of a new High-End GPS Devices, capable to measure with Doppler GPS functionality. This High-End Device will is based on the ThingSee, and is equipped with our own custom software, making it fully equipped for our special features like the 10 seconds run, the Nautical Mile, Alpha speeds, etc etc.
It's available for pre-sale rigjht now on
http://shop.gps-speedsurfing.com/p/67/thingsee-one-gp3s-edition-v1 The second track that we working on is the use of other GPS Devices, most import device that will be on the market will be the Locosystech GX-52. This device already has been approved and we are very happy that Locosystech again produces a custom products with special GPS-Speedsurfing.com firmware on it out of the box. You can buy the device at several online & offline stores.
Besides that we have worked on standard devices, we realize that this standard devices will never reach the high-end specifications of Doppler GPS, but for normal day-to-day use, and the average surf-sessions this devices could be a nice alternative for some windsurfers. We are exploring the possibilities of enhancing the software of “standard” GPS-Devices. Target is to reach the current standards of GPS logging at GPS-Speedsurfing.com, so making it possible to measure at a 1 per second rate, and log the number of satellites.
In general we allow any GPS Devices that’s is capable of logging GPS Data with a sample rate of 1 per second and support the .GPX data format. Please notice that the use of .GPX format is
not allowed for records, and is more suited for normal day-to-day surf sessions. The only fully approved format at this stage are the .SBN, .SBP & .UBX format.
For speedfreaks that already own a Android phone a good alternative good be the App GPS Logit,
www.gps-speed.com/gpslogit.html , this App is still under development by Manfred Fuchs, and could be a good alternative for starting speedsurfers. The App produces doppler speeds, at the same quality level of the old GT-11.
YAWN 
