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ArduPilot / MissionPlanner

Mission Planner Ground Control Station for ArduPilot (c# .net)
http://ardupilot.org/planner/
GNU General Public License v3.0
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Command coordinates precision vs. ArduPilot log #1393

Open ThomDietrich opened 7 years ago

ThomDietrich commented 7 years ago

I'm not sure where to file this issue.

MissionPlanner stores waypoints/commands with coordinates in the following way (example):

7   0   3   16  0.000000    0.000000    0.000000    0.000000    51.077282   10.988579   20.000000   1

ArduPilot later creates logfiles with the following content:

CMD, 42187994, 9, 7, 16, 0, 0, 0, 0, 51.07728, 10.98858, 20

As you can see, the precision differs by one decimal place. One could argue if this is a bug or not but it for sure confused me while doing a custom analysis. The additional MP decimal suggests more than ArduPilot can handle. Would you consider removing it?

magicrub commented 7 years ago

Mission Planner uses Double Precision. MAVLink usually uses float (although integer is available and better). Ardupilot logs are float. This is a side effect of a float to integer transition on Ardupilot for improved RTK accuracy.

ThomDietrich commented 7 years ago

Thanks for the explanation. What's your opinion on that matter?

meee1 commented 7 years ago

Please check this link https://en.m.wikipedia.org/wiki/Decimal_degrees

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On Fri, Oct 21, 2016 at 10:54 PM +0530, "Thomas Dietrich" notifications@github.com wrote:

Thanks for the explanation. What's your opinion on that matter?

You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/ArduPilot/MissionPlanner/issues/1393#issuecomment-255429891

magicrub commented 7 years ago

Mission Planner uses Double Precision. MAVLink usually uses float (athough integer is available and better). Ardupilot logs are float. This is a side effect of a float to integer transition on Ardupilot for improved RTK accuracy.

On Fri, Oct 21, 2016 at 8:48 AM, Thomas Dietrich notifications@github.com wrote:

I'm not sure where to file this issue.

MissionPlanner stores waypoints/commands with coordinates in the following way (example):

7 0 3 16 0.000000 0.000000 0.000000 0.000000 51.077282 10.988579 20.000000 1

ArduPilot later creates logfiles with the following content:

CMD, 42187994, 9, 7, 16, 0, 0, 0, 0, 51.07728, 10.98858, 20

As you can see, the precision differs by one decimal place. One could argue if this is a bug or not but it for sure confused me while doing a custom analysis. The additional MP decimal suggests more than ArduPilot can handle. Would you consider removing it?

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/ArduPilot/MissionPlanner/issues/1393, or mute the thread https://github.com/notifications/unsubscribe-auth/AEj7G7JWdEwWS57Bog6dQGVQNf4HJZuTks5q2N7RgaJpZM4KdXz- .

magicrub commented 7 years ago

The sooner we can convert to double natively on Ardupilot, the better. However, that eats up lots of ram and slows down computation as well as increases demand on external flash memory and its bus. This would be a more natural progression to a Linux only benefit due to limited external flash memory on pixhawk.

On Oct 21, 2016 10:24 AM, "Thomas Dietrich" notifications@github.com wrote:

Thanks for the explanation. What's your opinion on that matter?

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/ArduPilot/MissionPlanner/issues/1393#issuecomment-255429891, or mute the thread https://github.com/notifications/unsubscribe-auth/AEj7G5403-kCQTffBXpp8XqwaMxr77A7ks5q2PVVgaJpZM4KdXz- .