Can 'calibrate reflectance' function work on customised panels?

[dobedobedo]

Hi,
I tried the calibrate reflectance function on my old data which was taken by Sequoia on 2 Feb 2017. We didn't have a micasense panel at that time so we deployed multiple known reflectance customized panels on the ground. I used the black panel (4.2% reflectance) as reference in the calibrate reflectance dialogue. However, no matter how I tried by selecting panels only or both panels and sun sensor check, I always get a very weird result in green band as attached. I can send you the panel images I used, though the usable area is only several pixels.
Another question is how to convert the reflectance calibrated image to reflectance (0 to 1) for Sequoia images? There are two sayings I've heard: 1) divide the DN value by 32767, and 2) divide the DN value by maximum DN (65535?). Which is the correct answer?
My PhotoScan Pro version is 1.4.1 build 5929 64-bit if it helps.

[Alexey Pasumansky]

Hello dobedobedo,

Can you please clarify, if you have used calibration by panel option in your project? If so, then have you used only one ground panel (and applied the masks to the corresponding images) and which values you have used for the panel reflectance values?

Also do the old Sequoia images contain the following tag: Sensor Model?

As for the normalized reflectance values, PhotoScan is following MicaSense recommendations, where 100% reflectance corresponds to the 32768 value:
https://support.micasense.com/hc/en-us/articles/215460518-What-are-the-units-of-the-Atlas-GeoTIFF-output-

[dobedobedo]

Hi Alexey,
Yes I check 'calibration by panel' option, as well as both 'by panel' and 'sun sensor'. I followed the manual instruction to set primary channel to each band and mask every except the black panel (as attached image), and set the reflectance to Green: 0.0416, Red: 0.0416, Red edge: 0.042, NIR: 0.042. I ran 'calibrate reflectance' twice since I've heard there's a bug at the moment.

I check the metadata and there are 'Sensor Model' tag under XMP.