Plots for trends in metadata for occulter radius and plate scale

[detoma]

Make a plot of IMAGESCL over the mission to test the nominal plate scale. Compute median, mean, and sigma.

Make a plot of RSTWVL over the mission and consider how to fit data with a spline. It may require adjustment for the wavelength shift when the filter was retuned to put data on the same scale. Joan and I notice that RSTWVL seems to become smaller on cloudy days or late in the day when clouds gets in and would like to correct for that.

Tasks

• color code points in IMAGESCL plot by occulter ID in ucomp_mission_image_scale_plot.pro
• create text file corresponding to IMAGESCL plot with columns date/time, image scale, plate scale, occulter ID
• tighten scale on TCAM/RCAM radius on the centering plot to about 320 to 360

[mgalloy]

Below is the IMAGESCL plot. It is in the engineering directory:

It plots the plate scale, by epoch, in the red with an error band.

[detoma]

We discussed this plot and changes happen when the observers change occulter. This point to an error in the measured occulter radius in the lab. The plan is to bring back the occult's and have them measured again with high accuracy. We should measure the diameter at different position angle, i.e. 0, 45,90,135deg, to verify that they are round but all the data we have from CoMP and UCoMP point to the ocular being nearly perfectly round. It seems the problem is that we do not know the diameter accurately enough.

[detoma]

It would be useful to do the following:

• Plot eccentricity data over the mission (my recollection is that eccentricity is negligible and this was also true for CoMP except for one time period when we thought the occulter was inserted with a tilt). Eccentricity over a certain value could be a flag to check that the occulter in the correct position

• Plot the average radius for all wavelengths. I suspect this get noisier for the fainter lines. If so, and if we convince ourselves we know the platescale well for 1074, can we derive a platescale for those wavelengths from the 1074 one?

• Plot the radius of the occulter for camera 0 and camera 1 over the mission. It seems there are times when the difference between the two cameras is quite large, e.g. the difference is over a pixel for 1074 in March 2022. This should not happen if the images are properly corrected for distortion and our algorithm to find the radius is robust.

[mgalloy]

I have plots the contain the more recent data, but they look weird because of the big gap.

[mgalloy]

The other wave regions look fairly similar:

[mgalloy]

Eccentricity of the mission for 1074 nm (I have plots for the other wave regions if you want them):

[mgalloy]

I am not sure what you mean by "Plot the average radius for all wavelengths.", but I do have the radius per camera by wave region, e.g., for 1074 nm:

[detoma]

Thank you Mike! For average radius I meant the average of camera 0 and camera 1 that we use for the plate scale, but what you plotted is perfectly fine. Can you please make additional plots where you change the scale so we can see better how stable it is? let's try 330 to 360.

[detoma]

When looking at the difference between the two cameras, is larger early on. RCAM is systematically smaller at all wavelength. I found some notes from Steve saying this difference could be a focus problem.