The (very) beta version of the KA72 SpeedReader is online at www.ka72.com/

So far, the application can parse your (GT-11 or GT-31 SBN) GPS file and tell you information from the file header and your 2 second peak speed.

Feel free to try it out and send me any feedback on odd/inconclusive behaviour.

So far I have noticed that files uploaded from a very early firmware release of the GT-11 do not get parsed correctly. Otherwise, the results have all been checked against Realspeed and are in line.

The purpose of the service is to give beginner speed sailors an opportunity to get running with their new GPS without having to learn about the software straight away. It is planned to provide the basic results back needed to use with the GPS Team Challenge competition, and to encourage more people to enter the competition that might otherwise have been put off by the complexity of using their GPS.

If there are further updates in the next week or so I will post back to this thread. (I'm planning on adding some more divisions, starting with the 5x10.)

Dylan.

That's so cool Dylan, it gave me the exact same speed as RealSpeed did for my latest session

I can't wait till it's been integrated into the GTC

That is very clever Dylan -is certainly the future and great for new players.
Not wanting to sound like a whinger but i'm interested in what the calculation/algorithm is. My recent file through your tool gave xx.04 vs xx.16 on GPSAR pro [doppler].

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25 said...

That is very clever Dylan -is certainly the future and great for new players.
Not wanting to sound like a whinger but i'm interested in what the calculation/algorithm is. My recent file through your tool gave xx.04 vs xx.16 on GPSAR pro [doppler].

That's similar to the decrepancy you can get between GsarPro and Real Speed.
So I guess Dylan's doing the same thing as Mal and using 3 doppler samples to get the 2 sec average.
Unlike GpsarPro that (I think ) uses only 2 samples.
There's been a discussion about the pros and cons of this before, from memory it goes along these lines.
The doppler result is an instantaneous reading, the gap between 2 results is only 1 sec, to get 2 secs you need 3 readings.

Very Nice Dylan it gave the same result as Realspeed.

Thanks for the input so far.

Yes, basically it is using three consecutive readings to determine the 2 second peak.

Something I've observed from the submitted files this evening, is that not everyone is using the latest firmware revision for their GPS.

IMO:
For the GT-31 the ideal revision is V1.2(B1106T)
For the GT-11 the ideal revision is V1.62(B1115)

When you submit a file, it will report on the firmware revision you have installed, and if yours doesn't match, you should consider upgrading.

I've added two new divisions, the 5x10 and the 1hr, plus firmware detection.

The 5x10 is spot on with RealSpeed in my test files, except where there is an odd record involved in the calculation (specifically, I have one where there is a 15 second pause, which the two systems calculate differently.)

The 1hr is spot on about 50% of the time, and very close (<1kt outside) the rest of the time. Still ironing out the bugs in that one.

The firmware detection will tell you where to get the latest firmware if it detects you are using an old one. I must admit, I'm not certain about the GT-31 firmware, so if anyone has one that is upgraded to the latest version and could upload a file to see if it is properly recognised as the latest, that would be great.

Dylan.

Dylan has implemented the slightly better method of calculation that takes the average of the doppler speeds that span each second to determine the speed over that period.

I am told by Yann that GPS AR Pro also provides this as an option and is called the Trapezoidal method. Manfred doesn't implement this method yet in GPS-Results (that I know of).

As this is a better method when working with sample data, it should be the preferred method of calculation.