jburkepile
commented
1 year ago I took a quick look at the eccentricity of the occulters for different UCoMP wavelengths over the mission (these plots are produced by Mike). The plots show that 1074/1079 have the lowest eccentricity over the mission - as expected. The eccentricity is larger for the 637 nm line (also not surprising). The 789 nm line had larger eccentricity than the 637 nm line ... which was surprising. Also, all wavelengths show larger eccentricities in TCAM, especially starting in summer 2022. Plots are below.
detoma
mgalloy
bberkeyU
Description: We calibrate the distortion introduced by the UCoMP optical system (from the occulter to the cameras) by measuring the deviations in an image of a distortion mask (or grid) with equally spaced dots. The grid is placed at the location of the occulter and is imaged by both beams, so this also allows us to register the two beams. We assume that any subsequent small drifts in the x-y location of the cameras can be corrected with a small offset.
Issue: Currently, we use distortion coefficients measured at 1074 nm to correct the distortion at all the wavelengths. This is because it is difficult to measure at other wavelengths.
Questions: Is the distortion a function of wavelength? We could check this by comparing distortion coefficients at different wavelengths? Can the distortion at other wavelengths be computed by scaling from the 1074 coefficients or some other simple means?
Tasks