2000-09-18 (Flight #1768)
Aircraft Flight Summary
Flight Track Map
Satellite Images from goes-09
The CV-580 flew to SHEBA on this flight. During this flight, the CAR performed downward imaging of sea ice and a BRDF of sea ice arond SHEBA under diffuse lighting conditions. The CAR filterwheel channel was alternated between the 1.6 and 2.2 µm channels. At the end of the flight, the CAR door was closed, and dark scans were done with all filter wheel channels at all gain settings. A second data tape was started in the latter half of this mission.
19:08 UTC take-off; filter wheel set to 1.6 µm channel
200 approximate first recorded scan
522 shift from upward imaging position to BRDF mode
599 initial IR channel noise has settled down
741 shift from BRDF mode to downward imaging mode
870 carpet of white clouds, albedo is 0.61, altitude is 14,208 ft.
1298 switch filter wheel to 2.2 µm channel
1850 sea ice with some cirrus above the aircraft, albedo is 0.5, altitude is 18,500 ft.
2479 We are flying through sparse pockets of ice crystals.
2614 scattered clouds with shadows over sea ice, some cirrus above us. Albedo is 0.59 and GPS altitude is 19,000 ft.
2729 switch filterwheel to 1.6 µm channel, clouds filling in below us more
4910 sea ice with a few scattered clouds below. Albedo is 0.52 and GPS altitude is 19,100 ft.
5900 thick altocumulus on port side , scattered, very thin clouds (can see ground very clearly) . We are flying along a line of discontinuity in cloud cover. Albedo is 0.54 and GPS altitude is 18,900 ft.
9000 Attempted to rotate CAR to BRDF mode but was unsuccessful. Plane is moving too fast (118 m/s). The locked-in indicator light still lights up from both directions, so it's likely this is not a mechanical jamming problem, but an air loading problem overwhelming the motor (If the light fails to light up in either direction, there is likely a mehcanical jamming problem that will have to be fixed on the ground).
10300 During a bank turn of the plane, the CAR was successfully rotated to BRDF mode. Begin BRDF measurements, trying to avoid shadows from cirrus above, as well as brown haze layer. Altitude is 16,500 ft.
10994 Beginning of turn 1. Filterwheel set to 1.6 µm channel. Unstable altocumulus.
11240 Beginning of turn 2. Cirrocumulus just under us.
11435 BRDF scene, haze layer is above us . Albedos varying from 0.8 to 1.50. Albedo measurements are not to be trusted, they must be corrected for angle.
11506 Beginning of turn 3.
11768 Beginning of turn 4.
12014 Beginning of turn 5.
12260 Beginning of turn 6, switch filterwheel to 2.2 µm channel.
12495 Beginning of turn 7.
12798 End of turn 7 (too much cloud-shadow contamination now-BRDF measurements halted. Now descending towards SHEBA).
13943 sea ice around SHEBA , sea ice at 500 ft., more sea ice .
15947 Switch CAR to downward imaging mode
16390 Switch CAR to BRDF mode
20311 Main computer crash. RESTARTED NEW TAPE. (Note from flight engineer Don Spurgeon: This was not necessary, but no real harm done.)
10 (new scan number) at 22:36 UTC, starting of the second tape.
6500 (new scan number) CAR door closed. Went to filter wheel channel 1, and increased and decreased gain settings with door shut at all filterwheel channels.