Owl Boresight, flight day 174/2022, Alconbury

[wja]

First boresight with owl with adjustable roll. PhaseOne Also flown but data not received yet.

Received 24/06/2022 via FTP.

[wja]

Log from unpacking checks run on the Owl:

Running checks for OWL                                                                                                                  
Running check: arsf_check_library.checks.check_nav_timestamps                                                                           
Found timestamp rate not constant for the timestamp 120th in file /users/rsg/arsf/arsf_data/2022/flight_data/uk/owl_boresight-2022_174_Alconbury/thermal/owl/OWL174-22-4/capture/OWL174-22-4.nav                                                                                
Should be a timestamp every ~84 lines and the last timestamp was at 2606 lines                                                          
                                                                                                                                        
Will check timestamp from nav files                                                                                                     
Finished checking timestamp from nav files                                                                                              
                                                                                                                                        
Running check: arsf_check_library.checks.check_nav_last_frame                                                                           
Error in /users/rsg/arsf/usr/lib/python/site-packages/arsf_unpacking/unpacking_utilities.py : write_message: There is a timestamp for line number 9917 that does not makes sense                                                                                                
difference with the next timestamp is negative                                                                                          
                                                                                                                                        
Warning - The last timestamp in file: /users/rsg/arsf/arsf_data/2022/flight_data/uk/owl_boresight-2022_174_Alconbury/thermal/owl/OWL174-22-4/capture/OWL174-22-4.nav                                                                                                            
is for line/frame number 6220 from a total of 17306 lines                                                                               
There should be a timestamp each ~168 lines                                                                                             
                                                                                                                                        
Warning - The last timestamp in file: /users/rsg/arsf/arsf_data/2022/flight_data/uk/owl_boresight-2022_174_Alconbury/thermal/owl/OWL174-22-7/capture/OWL174-22-7.nav                                                                                                            
is for line/frame number 9917 from a total of 10262 lines                                                                               
There should be a timestamp each ~168 lines                                                                                             
Error in /users/rsg/arsf/usr/lib/python/site-packages/arsf_unpacking/unpacking_utilities.py : write_message: There is a timestamp for line number 9917 that does not makes sense                                                                                                
difference with the next timestamp is negative                                                                                          
                                                                                                                                        
Warning - The last timestamp in file: /users/rsg/arsf/arsf_data/2022/flight_data/uk/owl_boresight-2022_174_Alconbury/thermal/owl/OWL174-22-8/capture/OWL174-22-8.nav                                                                                                            
is for line/frame number 1 from a total of 10014 lines                                                                                  
There should be a timestamp each ~168 lines                                                                                             
                                                                                                                                        
Warning - The last timestamp in file: /users/rsg/arsf/arsf_data/2022/flight_data/uk/owl_boresight-2022_174_Alconbury/thermal/owl/OWL174-22-9/capture/OWL174-22-9.nav                                                                                                            
is for line/frame number 9917 from a total of 10188 lines                                                                               
There should be a timestamp each ~168 lines                                                                                             
                                                                                                                                        
Warning - The last timestamp in file: /users/rsg/arsf/arsf_data/2022/flight_data/uk/owl_boresight-2022_174_Alconbury/thermal/owl/OWL174-22-13/capture/OWL174-22-13.nav                                                                                                          
is for line/frame number 9917 from a total of 10497 lines                                                                               
There should be a timestamp each ~168 lines 

I don't think these are anything serious to worry about right now, but could be useful for troubleshooting if any issues arise with the nav data or nav sync.

[wja]

The old IPAS system is on the movable Owl mount.

IPAS data processed using SNEO basestation using old IPAS TC software. Lever arms are unknown at this point, navigation data will need processing again when these are known.

[wja]

Owl Boresight

3-band flightlines ran through the processing correctly, but pixels are in reverse order across the scanline, need to flip.

[wja]

Navigation Process

IPAS20 IMU navigation data (for use with Owl only) is completed.

Data quality looks good.

[mark1]

nadir lines: 2,3,6,7,10,11 look good with boresight: 0 0 0.2 compared to vectors. Note there are no opposing pairs in this set, so hard to judge along/across track errors due to roll and pitch.

36 degree lines: 4,5,8,9,12,13 are all opposing pairs and look to have some error along track. Unsure if can use the same boresight with these or not, and am slightly confused as to why they line up with vectors OK. Will come back to this in the new year when my cold has hopefully gone and I can think again.

[mark1]

For the 36 degree lines, boresight values -0.4 0 0 (prh) seem reasonable but with some distortions remaining in the data. These may be because the look angles are large and therefore the error component increases too (when projected towards the ground). I don't think they are "wobbles" due to navigation errors. But could be due to some other unknown reason.

[wja]

Have verified the above boresight values on flight 185.

For Owl angled at 24 degrees, the pitch as been increased slightly. Looks good for nadir and 36 degree data.

Going forward with the following boresight values for the Owl:

Angle	Pitch	Roll	Yaw
0	0	0	0.2
24	-0.2	0	0
36	-0.4	0	0