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Ticket Resolution Summary Owner Reporter
#106 invalid Hawk data very noisy in some bands benj benj
Description

Some Hawk bands are noisy to the point of uselessness. For example band 71 (1403nm), raw data from Nigg Bay line 3 (attached)

Also see over-water spectrum produced in level 3 image:

Hawk 8-pixel average spectrum over water in Nigg Bay

Spectrum cannot really be used for anything much - there is no means of quality controlling the data

Data issue occurs over more than one flight, possibly there are sensor problems with some Hawk bands. See eg. Latera band 71, similar to Nigg Bay:

Hawk band 71 (line 1) raw data from Latera

#107 invalid Eagle/Hawk spectrums misaligned benj benj
Description

If you plot Eagle and Hawk processed output on the same graph (see attachment) there's about a 30nm overlap for the spectral range, and the instruments don't seem to agree in this overlap. Even if the instruments don't give the same magnitude, the absorption features shown should align (and they don't). This suggests that the spectral calibration of one or both instruments may be out by up to 100nm, which appears to be the displacement needed to make the two graphs align.

Eagle/Hawk spectra from level 1 data (Nigg Bay line 3). Top lines are over land, bottom over water (with possible sun glint).

#110 fixed Azspec processed Hawk data has spectral spikes mggr benj
Description

Azspec-processed level 1b hawk data does not appear to be correct - it contains large anomalous spikes in some bands, seemingly correlated to very low data values. Eg from Nigg Bay line 3:

Hawk spectrum from azspec-processed level 1b file over water (8px average)

Compared to Caligeo spectrum from same pixel:

Hawk spectrum from caligeo-processed level 1b file over water (8px average), same place as azspec example

Could be underflowing, but would expect a much higher value for the spikes (~65k) in this case. Might still be underflowing and then changed by maths in azspec though.

Note extended from ticket #106, but separate to Hawk noise issue

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