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CAL-REGRESS Error Not Enough Valid Points
20-Dec-2022, 05:22 PM, (This post was last modified: 20-Dec-2022, 05:23 PM by FCarotenuto.)
#1
CAL-REGRESS Error Not Enough Valid Points
I'm trying to run a 3-targets inflight calibration on some CASI/SASI hyperspectral data. Targets are a black tarp, an asphalt and a bright gray tarp. 
I have airborne at-sensor radiance (1-10000 range) and ground target reflectance (0-1 range). Target reflectance has been spectrally resampled to the airborne sensor.
I've run the c1 inflight calibration over the 3 targets obtaining the various *.cal, *.adj and *.rdn files that have been renamed sequentially (calib1, calib2, etc.).

Still, when I try to run the CAL-REGRESS module it stops with the following error: "PLOT: Not enough valid and unique points".
I've checked the various files and they seem to have been written normally. My only guess, by checking the *.adj files, is that there's a rounding problem. 
In the *.adj file, target reflectance is converted to percentage with precision 1 only and this yield bands with the same reflectance value within the same target. For example, the black tarp has all reflectance values equal to 4.5% between 550 and 830 nm. 
The original spectrally resampled reflectance, though, had 7 digits precision and the values were not at all identical between the various bands.

Could this be the problem? What can I do to address this?
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21-Dec-2022, 09:19 AM,
#2
RE: CAL-REGRESS Error Not Enough Valid Points
We need to analyze the situation based on your data. Please forward the outputs for the three panels to support@rese-apps.com such that we can check what happens.
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22-Dec-2022, 04:38 PM,
#3
RE: CAL-REGRESS Error Not Enough Valid Points
(21-Dec-2022, 09:19 AM)reseadmin Wrote: We need to analyze the situation based on your data. Please forward the outputs for the three panels to support@rese-apps.com such that we can check what happens.

Thank you for your support! I've just forwarded the files.
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24-Dec-2022, 12:31 PM,
#4
RE: CAL-REGRESS Error Not Enough Valid Points
The problem was caused by zero radiance in some bands which could not be calibrated. The issue is cought in the cal_Regress code now and included in the latest build of ATCOR4.
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