It seems like if a WC team used GPS logging for analyzing their flights after the fact, they might gain an advantage over others that don't. The weight of a DLG is low enough now that putting a 11 gram GPS unit (1.5" x 0.79" x 0.35") in it wouldn't make that much of a difference and might actually help with weight. It could probably be reduced even more by removing the thick heat shrink and using a much thinner material.

For practice it is not an issue of course except the need to disable or remove it for competitions which would kinda be problematic. That is unless it only logs locally on the DLG itself but that would require more weight for more processing.

From what I gather from the rules, GPS would only be allowed in a competition if it didn't transmit the data back to the transmitter. If it only logged the data internally on the DLG somehow, it would not go against the rules. I hope they eventually change that so that the rules state that they must be ignored for flight input, display, and announcement on the transmitter. This would allow you to log the data on the transmitter but not call it out or display it. OpenTX has a feature called fai mode that ignores all incoming data telemtry data except battery voltage and RSSI from the sensors when in that mode but I would want it to still be able to be logged for analysis after a competition. A feature request to change that is possible I bet to have a mode that logged but does not allow the data for display/announcement.

Whatever the solution, ideally you would want the GPS unit allowed by either conforming to the existing rules by logging locally and not transmitting it back the the Rx which would require more weight and size for the processing and storage of the data in the plane or the much better solution of getting the rules changed so that it allowed logging of GPS to the Tx but not allow announcement or display of the GPS data. Maybe eventually that might be lifted and actually allow display of GPS (not that you would look at the display while flying ) and announcement of it as I doubt the top competitors would change in position even if that were allowed.

If designers thought about GPS as part of the design of DLGs, A tiny bit more room could be made into the design for the GPS unit to go at the top maybe even in a specially designed area for it.

An example of viewing the flight in 3d on a map with playback controls.
https://ayvri.com/scene/1q5roem453/9kd0q67w52

How I got the data into ayvri.com...
- Export the logfile as kmz or kml from OpenTX Companion Log viewer. (Google earth must be installed and path to google earth exe setup in the OpenTX settings.
- Convert the kml or kmz to gpx format using GPS Visualizer: https://www.gpsvisualizer.com/convert_input
- Import gpx file into ayvri.com

11g is not a lot, but it's enough to affect cg. I have room in my snipes for it, but up in the nose it can really through the balance off if you don't need the weight

I don't quite see the advantage to knowing where you flew.
The air for that flight will never be exactly the same again.
You won't have any idea of the air you are flying in after the fact, so what is there to learn?
Help me out here as to how this would be of any value to the competition pilot.

Unless the logger had an accelerometer that could accurately log flight times if you wanted to dispute an official timer's reading.

Mickey, Where I found it interesting was after the flight going over it and seeing where I went left when I should have gone right and trying to think back to that time. In the example that I gave I made some mistakes going the wrong way and it is very clear looking at it where I made the mistakes. Looking at the 3d track, It seemed to remind me of the flight where I would have normally forgot all about it. My memory is not the greatest . If you can not recall the flight at all to know what you were doing at the time, maybe it wouldn't be as useful for that. At a minimum, It can sometimes show how often you are coring well and when you are not based on going faster and slower when going up over the same thermal and what direction you were compared to the thermal (again based on the altitude track). Now image your entire team and everyone else showing their track at the same time on that 3d playback. Most pilots only see around what they are doing so seeing when someone else did better and where and how much better at the same time you were somewhere else might be useful. Of course nothing can be said to be 100% sure about the track vs coring because of variations of the thermal itself, but I think it would still overall be useful.

I am just a middle of the pack guy at the regular f3k competitions (not f3k world stuff ) so I am the first to admit that my idea of what can help is only based on my limited skill level. I have no idea if this would actually benefit a top competitor at the worlds. It seems most of the top scores come down to quick times after thermalling ability. I again... am sure my perspective is off because of my skill level so I realize any ideas I come up with should be taken with a grain of salt... maybe some pepper too.

It seems like to me that it could be useful to some extent for those where playing back in their head and seeing the 3d track might reveal something that just memory alone wouldn't.

Plus... it would be very cool to see the entire competition played back. I would probably spend a lot of time just watching other competitions for the fun of it. I could see a few people getting together to reminisce over previous competitions.

Another plus is that the technology might attract some of the kids that see some cool 3d playbacks of flights .

Adam, I think your perspective is skewed by your long flight times.
Contest flying is a whole bunch of 1, 2, 3 and 4 minute flights where the emphasis is on reading the air before throwing or while coming back in to relaunch. We dont fly 20 or 30 minute flights to need to go back and replay a thermal that far back in time.
Most comp pilots are more worried about finding air rather than precisely coring one thermal for 10 minutes, though most are good at it anyway.
Try flying the tasks for practice to see if gps tracking would benefit your improvement.

I do understand where you are coming from and i do mainly look for long flights when I am playing around (which is most of the time ). I don't do 20 or 30 minute flights all the time though as I am not that good to find the thermals all the time. The example flight was 5 minutes and I brought it back down. I will post the altimeter graphs of my flights today to get an idea of my durations. It was a little windy today.

Do you not think playing back your entire days flights and seeing where you caught the best part of the thermal would not helpful at all?

That is a good idea. I will set up the GPS on my Binary IV (easier to fit and tape the canopy) and do a mini solo competition and see how that goes this weekend or next. I guess I will find out how helpful it is to me. Maybe an expert looking at the track might be able to make some observations that I wouldn't too even without knowing the conditions as they will see how fast the DLG drifts in the thermal and get an idea about wind speed, etc.

100% what Mickey said, what makes a great contest pilot is knowing where to go before you even throw the plane. Reading and making large course adjustments once already in the air should be plan B, but it should also be based mostly on information gathered from ground signs. The 3d mapping would be a cool feature maybe in determining where the thermals are generating that day or how they are behaving, but that data would be only useful for a short period of time because as the day develops, the way the thermals behave will change.

I'm not really sure I see the point. How are you going to tell you should have gone right instead of left? Thermals shift, break-up, surge, etc., which no GPS trace is going to tell you anything about.

But if you really want, Aerobtec makes a 9g logging GPS with a built in barometric altimeter too, so you can log climb rates and GPS to your hearts content. Tiny little telemetry adapters are also available for sending the GPS, vario, and altimeter data to your Tx for practice as well.

http://aerobtec.com/altis-gps/

Kevin

Originally Posted by xStatiCa

Do you not think playing back your entire days flights and seeing where you caught the best part of the thermal would not helpful at all?
.

Not in the least, because it would be worthless in tellling where the next thermal is 3 minutes from now, which is all I want to know.
You talk like thermals are some correlated to fixed coordinates, when in fact they are only correlated to the current air mass around you at that instant.

I certainly realize that you can not look at a previous thermal and know where a new one is. The purpose of looking at previous flight tracks is mainly just to see how well you were coring them. In the example 3d track, I flew out of it's core and then corrected to go back in.

Originally Posted by xStatiCa

I certainly realize that you can not look at a previous thermal and know where a new one is. The purpose of looking at previous flight tracks is mainly just to see how well you were coring them. In the example 3d track, I flew out of it's core and then corrected to go back in.

Its cool, but how does it help you fly better?

Originally Posted by Wave Glider

100% what Mickey said, what makes a great contest pilot is knowing where to go before you even throw the plane. Reading and making large course adjustments once already in the air should be plan B, but it should also be based mostly on information gathered from ground signs. The 3d mapping would be a cool feature maybe in determining where the thermals are generating that day or how they are behaving, but that data would be only useful for a short period of time because as the day develops, the way the thermals behave will change.

I definitely see the logic in all your arguments and I did not intend for that data to be used to predict future thermals. As I mentioned to Mickey, the idea is for looking back at the flights and seeing how well you cored the thermal. Sometimes I veer off and then come back to it which is shown in the example 3d flight. That information cannot be used for future flights. It might show that I need focus on that more though if it becomes obvious I am slightly missing the thermals often. It might help if I analyze this later that night so that I might remember what I was thinking when I made the decision to veer off. That is the idea anyway. I have no idea if it will help me or not. Maybe just the immediate feedback when you are flying is all that is needed and any flight analysis later could only give general info like showing how often I am coring well or not. Even if it does turn out to be helpful to me though I assume the top pilot's coring skills are already honed so it might be completely useless for them.

I still like the idea of being able to play back previous competitions. I realize that getting to that point is not in the foreseeable future though. It is unlikely to get everyone to put a GPS receiver in their competition DLGs . I can dream anyway that one day I might be able to play back the full competition in 3D showing all the pilots and seeing who is winning like I was there again.

Originally Posted by kcaldwel

I'm not really sure I see the point. How are you going to tell you should have gone right instead of left? Thermals shift, break-up, surge, etc., which no GPS trace is going to tell you anything about.

But if you really want, Aerobtec makes a 9g logging GPS with a built in barometric altimeter too, so you can log climb rates and GPS to your hearts content. Tiny little telemetry adapters are also available for sending the GPS, vario, and altimeter data to your Tx for practice as well.

http://aerobtec.com/altis-gps/

Kevin

I do realize it is not useful for foreseeing the future as mentioned above.

Thanks for that link. I was not aware of that device. It really looks like a nice unit and has quite a few features. It is bigger though than the FrSky GPS receiver which would make it harder to get to fit in my DLGs at least.

Originally Posted by xStatiCa

Thanks for that link. I was not aware of that device. It really looks like a nice unit and has quite a few features. It is bigger though than the FrSky GPS receiver which would make it harder to get to fit in my DLGs at least.

The Aerobtec GPS is actually smaller than the FrSky GPS ( 29x22x11 = 7018 mm^3 Aerobtec; vs. 40x20x9mm = 7200 mm^3 FrSky). It runs at a 10Hz sampling rate, rather than the 1Hz of the FrSky GPS. It does barometric pressure altitude, and logs all the data.

I also find the FrSky GPS takes a very long time to get a lock compared to my oXs GPS. I suspect the Aerobtec uses a better GPS sensor as well.

Kevin

I started to type that it was wider but just said it was bigger instead. I should have left the original text . It is wider by 2mm and 2mm can make a difference in tight spaces (and it would in my setups) as it has to lay down flat for the antennae position. Is is nice that it is shorter.