Rules (it's raining)
Team leader meetings at these big comps are always interesting, today (day 2) was up there - since GPS timing of tasks have been accepted there has been a problem using them for races. Apparently some GPS keep time differently to others. It has been proposed that one particular model can have a time 10 seconds in advance of others - that could mean that two pilots could race over the finish line absolutely together, however the pilot with GPS A could be recorded as being up to 10 seconds ahead of the pilot with GPS B. Ten seconds using RACE and GAP 2000 for scoring can add up to significant points when the pilots really should get the same points.
For this reason senior competitions prefer to have a physical goal line staffed by observers who manually time the first 15 pilots over the line. The pilot's manual time takes precedence to their GPS time.
Sounds good, a couple more staff to handle the timings but hey, this is a senior comp and money is not a problem. But, hang on a mo, what about safety. By making a physical line the end of the task and the race then we are asking the pilots to speed into goal as quickly as they dare, on a paraglider this means using speed bar and trimmers, often when the pilots are low, close to the ground. This is a significant safety issue as a comp wing collapsing on full speed close to the ground could be very dangerous.
Ok, one solution could be to have an end of speed section perhaps 1km before the goal - pilots would race through that 1km ring but would also need to have the height to keep on going to the goal, the idea here is that the racing would still be done but with much more height, the last 1km to goal would not be a part of the speed section but would need to be covered to for the pilots to win all their points.
Good solution, safety, safety - unfortunately we are back to the race section being timed by GPS and the the pilot with GPS A is smiling, consequently many senior comps stay with the dangerous race across a physical goal line.
The issue is known to the FAI and CIVL and apparently they have been looking into the problem. Perhaps time for them to stop looking and start acting. How about standardised GPS equipment confined to GPS which are known to have correct times or a list of excluded GPS which are known to have incorrect times. That then means no more unfair GPS time advantage so that then means everybody is happy with 1km end of speed section and no more dumb full speed into goal low to the ground (which can hurt).
One could also ask why aren't we using RACE and GAP 2002 as it handles this all much better (although not perfectly), so why are we using GAP 2000 - perhaps more tomorrow....
webby
For this reason senior competitions prefer to have a physical goal line staffed by observers who manually time the first 15 pilots over the line. The pilot's manual time takes precedence to their GPS time.
Sounds good, a couple more staff to handle the timings but hey, this is a senior comp and money is not a problem. But, hang on a mo, what about safety. By making a physical line the end of the task and the race then we are asking the pilots to speed into goal as quickly as they dare, on a paraglider this means using speed bar and trimmers, often when the pilots are low, close to the ground. This is a significant safety issue as a comp wing collapsing on full speed close to the ground could be very dangerous.
Ok, one solution could be to have an end of speed section perhaps 1km before the goal - pilots would race through that 1km ring but would also need to have the height to keep on going to the goal, the idea here is that the racing would still be done but with much more height, the last 1km to goal would not be a part of the speed section but would need to be covered to for the pilots to win all their points.
Good solution, safety, safety - unfortunately we are back to the race section being timed by GPS and the the pilot with GPS A is smiling, consequently many senior comps stay with the dangerous race across a physical goal line.
The issue is known to the FAI and CIVL and apparently they have been looking into the problem. Perhaps time for them to stop looking and start acting. How about standardised GPS equipment confined to GPS which are known to have correct times or a list of excluded GPS which are known to have incorrect times. That then means no more unfair GPS time advantage so that then means everybody is happy with 1km end of speed section and no more dumb full speed into goal low to the ground (which can hurt).
One could also ask why aren't we using RACE and GAP 2002 as it handles this all much better (although not perfectly), so why are we using GAP 2000 - perhaps more tomorrow....
webby
posted by Unknown at 4:37 pm
10 Comments:
Is this just the 14 sec gps time error or something new
The 14 sec error only effects older gps units.
http://en.wikipedia.org/wiki/Gps
Perhaps mount a high definition video camera at the end of the speed section pointing vertically upwards, have number stickers or ordered, multi-color patches (or a big bar code, - easer to see?) on the wing. The top of the frame would be aligned at right angles to the course line. Finish time taken at midline of the frame. Some sailplane tasks have min/max height limits on goal arrival. Make it more than 1500ft? Has this been tried? How high is still visible? (hence big coloured patches might be better than numbers.)
How about a video camera located on the course at the end of speed section, pointing stright up and aligned so that the course line runs top to bottom. Implement a minimum goal crossing height of 500m for safety, perhaps 1000m maximum? Should be pretty easy and quick to review the tape as long as the camera clock is synchronised with a (known calibration) GPS.
Thanks for the updates. Hope you get less time for doing them (more time flying) soon though.
I can recall at comps having to register my GPS serial number and get a sticker put on it. How hard would it be to check the time on the unit when this is done?
I guess registration is a fairly busy and annoying part of the comp already and this would make it worse.
On my old Garmin 12 XL ver 3.53 I get about a 14 sec difference between my tracklog and the recording from my NMEA output.
So if I want to get to goal slightly earlier I would need to download my tracklog recorded by my vario from the NMEA output of the Garmin 12
Typical, U Aussies; still arguing about Rules (day 2) of Comp.!
& U call us The Wingeing Pommes!
Which reminds me, You used to be a Yorkshireman, Brian.
How come the Aussies had to borrow TWO team members from abroad ?
(1x KIWI, 1x Pomme.)
Hope the rain stops so you all go flying.
GO High, Go Far, PhilB
I presume the error is consistent throughout the flight - eg GPS A will always be reading 10 seconds ahead? If so, doesn't this mean the person with GPS A will leave the start 10 seconds earlier as well? That potentially opens up a whole new can of worms.
If the time to complete the race is taken purely from the GPS - ie the early 10 second start and the early second finish, then duration would at least be accurate. And in a short period of time, those with GPS A would be buying GPS B, because who wants to have to lead by more than 10 seconds to win a task?
You would have to watch that you didn't cross the start line too early, but if you were in a close race to goal the 14 seconds could make a difference to which tracklog I submitted
Plenty of other GPS problems exist too. Garmin units do predictive track logging (cover your GPS and turn early at turnpoints .. or if you're about to drop short of goal) .. etc. I believe the scoring software for the PWC actually does corrections for these problems, perhaps the worlds should be using that software to download tracks?
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