A transfer from the original Astrodiscuss forum (from Compater)
For my current project I am using ISIS to calculate the subsolar and subspacecraft points for all pixels in map projected WAC images. Sato et al.,  describe the wide angle camera in detail and mention that the emission angle also depends on the band in question, i.e., the 415nm band in the visible file is up to 7.5 degree in along track direction while the 643nm band on the other hand is approximately 0 degree in along track direction. However, if I call the campt command for ground pixels to output the angles and subspacecraft point I only get one value. Which wavelength channel does this output represent? From my understanding when the images are map projected all channels are
“georeferenced” in between bands. So one pixel in the image cube all channels represent the same ground pixel. Therefore, a certain position on the ground would be captured from slightly different spacecraft positions and each channel should have a different subspacecraft point. The smallest emission angle, which is calculated based on the subspacecraft points and a vector [0,0,1] for the surface normal, in the entire image is usually approximately 6 - 7.5 degree. Am I, therefore, right if I assume that ISIS is calculating the values for the 415nm wavelength channel? I couldn’t find any information about which channel ISIS is using. Thank you for your help in advance.