SwathS, flight day 200/2021, Alconbury (Boresight)

[dac]

Data location: /users/rsg/arsf/arsf_data/2021/flight_data/SwathS-2021_200_Alconbury_boresight

Data arrived from Kings College London via FTP on July 20th 2021

Scientific objective: Joint NASA and ESA campaign flying JPL’s HyTES thermal instrument over sites in Europe with a focus on crops and soil.

PI: Martin Wooster

[wja]

Navigation Processing

SBET file produced with POSPac.

Following OS basestations used:

• SNEO
• NEWR
• STEE
• WELL
• PETE

Will need to convert from UTC to GPS time for use in CaliGeo (18 leap seconds difference).

[wja]

SCT Values

Line 1 is missing bad pixel mask and has been skipped.

Lines 2 - 6 seemingly have the wrong FPS in the raw header. SCT error values that work on one end of the flihgtline do not on the opposite end of the flightline. SCT error offsets are between -0.6 and 0.0 for these lines.

Line	SCT Error
7	0.00
8	0.00
9	0.00
10	0.00
11	0.00
12	0.00
13	0.06
14	0.06
15	0.00

Will work on the boresight values using these line. SCT values may be further refined in the future.

[wja]

Nav Processing

Have reran the SBET generation with lever arms for GNSS to reference as 0. lever arms for reference to IMU are the values previously used (distance from GNSS to IMU).

RMS of SBET looks good. Z between 0.012 - 0.023 m. X & Y less than 0.013.

[wja]

Fenix Boresight

Have revised the SCT error values since applying the 2 frame delay reported by manufactorer. I was hopeing this would account for the small SCTs previously reported but it seems the frame delay has added to the timeing error rather than cancelling it out.

Line	SCT
7	0.04
8	0.05
9	0.04
10	0.04
11	0.06
12	0.06
13	0.13
14	0.13
15	0.12

[wja]

New build of aplnav is now applying 2 frame delay correctly.

SCT errors are 0.00. Have made minor tweaks to lines 8 and 14.

Line	SCT
7	0.00
8	0.01
9	0.00
10	0.00
11	0.00
12	0.00
13	0.00
14	0.01
15	0.00

There is still some distortion effects, have used lines 8 & 9 and 13 & 14 which are pairs of line in opposite directions for pitch and roll. Have used flight 2021 203b lines 4 & 5 for calculating heading as they are parallel in the same direction but overlap.

These values are not perfect, but I have reduced the amount of consistent offsets I have judged as boresight distortions as possible. There are still distortions with overlapping lines ~0-2 pixel offsets, but they are not in consistent directions.

Boresight values

Pitch	Roll	Heading
+0.67	-0.04	0.70