Post by deniseund on Aug 11, 2017 5:51:22 GMT -7
Hello all,
We have had several issues with the antenna tracking software- specifically, it will not point in the right direction. After practicing a bit, we have come up with some reliable methods of working around this issue that you can try if you experience the same problems. We are not sure if the problem is with the IMU or the arduino with possible RFD involvement; we have tried calibrating the IMU, mounting it in different configurations, and mounting it off of the arm, but once we power everything up (with Iridium and RFD both selected under AutoTracks) and start getting local data, the ground station will point at funny angles that do not match up to real directions. The offset angle is not consistent, for example, will power up and move to center, it will read 60 degrees bearing from north when it is actually pointing at 180 degrees. We will re- calibrate the IMU and update, but nothing happens. We will click "point at most recent balloon location" (which will be 60 degrees), the antenna will move to 309 degrees but read that it is pointing at 60. We will then tell it to move to center once again, but instead of going back to 180 degrees and reading 0, it will move to 40 degrees and read 30. We have not re- zeroed our servos, as the servo zeroing program will not initiate on either of our ground station laptops, but it does not appear to be a problem, as we are getting consistent tracking with our workaround. This is not a mounting or calibration issue, so it's not like we mounted the IMU backwards and are consistently 180 degrees off.
To get accurate tracking, we set the AutoTrack to "North facing" and manually enter our lat/long and elevation, then power up the servos and move antenna to center. It will not move to 0 degrees, but will read that it is pointing at 0 degrees in the Ground Station data box. We then use a compass to determine true north and physically lift the dish and point it at that direction so the actual bearing matches the reading, being sure to not jostle the servos. Under AutoTracker, we only select Iridium- when we select both Iridium and RFD, our angles are off (albeit less so than when using the arduino data). Once we do these steps, it accurately points at the Iridium payload and tracks it correctly.
Hope this helps, and if anyone has any insight into why the IMU/arduino/RFD are acting so strangely we would appreciate it!
We have had several issues with the antenna tracking software- specifically, it will not point in the right direction. After practicing a bit, we have come up with some reliable methods of working around this issue that you can try if you experience the same problems. We are not sure if the problem is with the IMU or the arduino with possible RFD involvement; we have tried calibrating the IMU, mounting it in different configurations, and mounting it off of the arm, but once we power everything up (with Iridium and RFD both selected under AutoTracks) and start getting local data, the ground station will point at funny angles that do not match up to real directions. The offset angle is not consistent, for example, will power up and move to center, it will read 60 degrees bearing from north when it is actually pointing at 180 degrees. We will re- calibrate the IMU and update, but nothing happens. We will click "point at most recent balloon location" (which will be 60 degrees), the antenna will move to 309 degrees but read that it is pointing at 60. We will then tell it to move to center once again, but instead of going back to 180 degrees and reading 0, it will move to 40 degrees and read 30. We have not re- zeroed our servos, as the servo zeroing program will not initiate on either of our ground station laptops, but it does not appear to be a problem, as we are getting consistent tracking with our workaround. This is not a mounting or calibration issue, so it's not like we mounted the IMU backwards and are consistently 180 degrees off.
To get accurate tracking, we set the AutoTrack to "North facing" and manually enter our lat/long and elevation, then power up the servos and move antenna to center. It will not move to 0 degrees, but will read that it is pointing at 0 degrees in the Ground Station data box. We then use a compass to determine true north and physically lift the dish and point it at that direction so the actual bearing matches the reading, being sure to not jostle the servos. Under AutoTracker, we only select Iridium- when we select both Iridium and RFD, our angles are off (albeit less so than when using the arduino data). Once we do these steps, it accurately points at the Iridium payload and tracks it correctly.
Hope this helps, and if anyone has any insight into why the IMU/arduino/RFD are acting so strangely we would appreciate it!
