Plot occulter radius difference

[mgalloy]

Over mission and daily time scales.

For filenames, use:

• YYYYMMDD.ucomp.WWWW.mission.radius-diff.gif
• YYYYMMDD.ucomp.WWWW.daily.radius-diff.gif

A range of -2 to 2 pixels seems reasonable.

[!NOTE] Time estimate: The issue, as stated, is completed.

[mgalloy]

Here is an example of the mission plot.

[mgalloy]

Here is the daily plot:

[bberkeyU]

This seems very odd. I can't think of why the apparent sizes of the occulters should change over the day. Do we have a similar plot for RCAM and TCAM individually? I would like to understand if the change is in both or an apparent change in just one camera.

[mgalloy]

Here is them daily centering plot with RCAM and TCAM separate:

[bberkeyU]

Thanks. It is not obvious what is changing at this y scale. I will try to do some digging when 8 get home.

[jburkepile]

Mike are these occulter measurements made after distortion correction?

[jburkepile]

Regarding the 20220901 plot ... the dramatic change in apparent radius of the occulter in both cameras after local noon may indicate the occulter is moving due to the change in gravity vector in the afternoon. That vector is in a different direction in the afternoon. Is it causing the occulter to move or tilt? If tilted we would also see the apparent eccentricity increase.

Is this visible on other days where we have data late in the day or is this peculiar to Sept 1?

[mgalloy]

These measurements are distortion corrected. Here is the eccentricity:

[bberkeyU]

Hi Joan,

I dont have a good explanation for the problem, but my gut says that since we are seeing a relative drift between the two beams, this problem is happening after the beam splitter and probably instead coming in at the occulter station. If it was a change in the occulter, we would actually have two problems: the physical shift in the occulter and the center finding code working differently per camera.

I think the more likely problem is some sort of shift in the camera position or the camera optics for one of the two beams.

The eccentricity plots are interesting in that they aren't identical for the waves program, but at least to first order, both cameras seem to follow the same curve.

Mike, where does the occulter radii live in the database? It looks like these should be in ucomp_eng. But when I run select * from ucomp_eng where file_name like '%20220901%'; All of the camera fitting values are null.

[jburkepile]

I have looked at a couple of level 0 images for this day. It is clear that there is a large x-pixel shift happening in the afternoon. Also, the pointing is worse in the afternoon. There is much larger asymmetry in the brightness around the occulter. This may make it difficult to measure the occulter diameter. Here are 2 level 0 images from Sept 1: the first is at 22:29:19 and the second is at 02:45:45

[mgalloy]

The database query is:

$ ucomp db -f production 'select file_name, rcam_radius, tcam_radius from MLSO.ucomp_eng where obsday_id=9473 and wave_region="1074";'
20220901.174648.65.ucomp.1074.l0.fts  None      None
20220901.200225.22.ucomp.1074.l0.fts  None      None
20220901.200859.51.ucomp.1074.l0.fts  None      None
20220901.211735.62.ucomp.1074.l0.fts  None      None
20220901.225458.57.ucomp.1074.l0.fts  None      None
20220902.011415.71.ucomp.1074.l0.fts  None      None
20220902.034702.73.ucomp.1074.l0.fts  None      None
20220901.182014.02.ucomp.1074.l0.fts  333.1343  333.2561
20220901.182246.38.ucomp.1074.l0.fts  333.1588  333.2752
20220901.185824.56.ucomp.1074.l0.fts  333.187   333.3203
20220901.190056.97.ucomp.1074.l0.fts  333.1729  333.3407
20220901.193635.96.ucomp.1074.l0.fts  333.2363  333.4121
20220901.193908.31.ucomp.1074.l0.fts  333.4893  333.415
20220901.200958.98.ucomp.1074.l0.fts  332.7243  332.8669
20220901.201032.55.ucomp.1074.l0.fts  332.813   332.9654
20220901.201106.15.ucomp.1074.l0.fts  332.8975  333.0643
20220901.201139.80.ucomp.1074.l0.fts  332.9583  333.0678
20220901.201213.38.ucomp.1074.l0.fts  333.0382  333.1932
20220901.201246.96.ucomp.1074.l0.fts  333.04    333.191
20220901.201320.55.ucomp.1074.l0.fts  333.0631  333.2443
20220901.201354.16.ucomp.1074.l0.fts  333.062   333.242
20220901.201427.76.ucomp.1074.l0.fts  333.0659  333.2177
20220901.201501.34.ucomp.1074.l0.fts  333.1305  333.2897
20220901.201534.96.ucomp.1074.l0.fts  333.1505  333.3297
20220901.201608.55.ucomp.1074.l0.fts  333.1795  333.2944
20220901.201642.13.ucomp.1074.l0.fts  333.2127  333.375
20220901.201715.71.ucomp.1074.l0.fts  333.2576  333.4198
20220901.201749.30.ucomp.1074.l0.fts  333.239   333.4299
20220901.201822.89.ucomp.1074.l0.fts  333.2705  333.3424
20220901.201856.49.ucomp.1074.l0.fts  333.2547  333.4141
20220901.201930.06.ucomp.1074.l0.fts  333.2562  333.4029
20220901.202003.65.ucomp.1074.l0.fts  333.2355  333.4048
20220901.202037.24.ucomp.1074.l0.fts  333.2749  333.4509
20220901.202110.82.ucomp.1074.l0.fts  333.2603  333.398
20220901.202144.45.ucomp.1074.l0.fts  333.3444  333.4233
20220901.202218.03.ucomp.1074.l0.fts  333.2732  333.4821
20220901.202251.61.ucomp.1074.l0.fts  333.2422  333.4591
20220901.202325.20.ucomp.1074.l0.fts  333.3132  333.4651
20220901.202358.79.ucomp.1074.l0.fts  333.3143  333.4503
20220901.202432.38.ucomp.1074.l0.fts  333.2936  333.5173
20220901.202505.97.ucomp.1074.l0.fts  333.2567  333.4188
20220901.202539.55.ucomp.1074.l0.fts  333.2608  333.3972
20220901.202613.15.ucomp.1074.l0.fts  333.2971  333.4132
20220901.202646.75.ucomp.1074.l0.fts  333.2935  333.5011
20220901.202720.33.ucomp.1074.l0.fts  333.2921  333.4839
20220901.202753.92.ucomp.1074.l0.fts  333.2432  333.4049
20220901.202827.52.ucomp.1074.l0.fts  333.2887  333.4056
20220901.202901.11.ucomp.1074.l0.fts  333.2806  333.431
20220901.202934.73.ucomp.1074.l0.fts  333.3126  333.4829
20220901.203008.33.ucomp.1074.l0.fts  333.3066  333.4739
20220901.203041.91.ucomp.1074.l0.fts  333.2943  333.4383
20220901.203115.49.ucomp.1074.l0.fts  333.2859  333.4946
20220901.203149.06.ucomp.1074.l0.fts  333.2516  333.3747
20220901.203222.65.ucomp.1074.l0.fts  333.3561  333.4124
20220901.203256.25.ucomp.1074.l0.fts  333.2848  333.5502
20220901.203329.83.ucomp.1074.l0.fts  333.2713  333.5085
20220901.203403.41.ucomp.1074.l0.fts  333.3237  333.5077
20220901.203436.99.ucomp.1074.l0.fts  333.3875  333.5035
20220901.203510.58.ucomp.1074.l0.fts  333.2726  333.4896
20220901.203544.21.ucomp.1074.l0.fts  333.2926  333.485
20220901.203617.80.ucomp.1074.l0.fts  333.2476  333.4578
20220901.203651.39.ucomp.1074.l0.fts  333.3513  333.488
20220901.203724.97.ucomp.1074.l0.fts  333.2104  333.4115
20220901.203758.58.ucomp.1074.l0.fts  333.2893  333.4512
20220901.203832.16.ucomp.1074.l0.fts  333.2812  333.468
20220901.203905.76.ucomp.1074.l0.fts  333.376   333.5246
20220901.203939.36.ucomp.1074.l0.fts  333.3942  333.5347
20220901.204012.95.ucomp.1074.l0.fts  333.3189  333.5723
20220901.204046.55.ucomp.1074.l0.fts  333.3073  333.5019
20220901.204120.14.ucomp.1074.l0.fts  333.2781  333.5585
20220901.204153.73.ucomp.1074.l0.fts  333.2232  333.4182
20220901.204227.33.ucomp.1074.l0.fts  333.2547  333.4544
20220901.204300.93.ucomp.1074.l0.fts  333.3252  333.4967
20220901.204334.54.ucomp.1074.l0.fts  333.2556  333.4483
20220901.204408.13.ucomp.1074.l0.fts  333.2159  333.444
20220901.204441.73.ucomp.1074.l0.fts  333.2271  333.4222
20220901.204515.32.ucomp.1074.l0.fts  333.2508  333.5167
20220901.204548.92.ucomp.1074.l0.fts  333.26    333.4677
20220901.204622.52.ucomp.1074.l0.fts  333.3025  333.4655
20220901.204656.13.ucomp.1074.l0.fts  333.339   333.4939
20220901.204729.73.ucomp.1074.l0.fts  333.3324  333.5202
20220901.204803.33.ucomp.1074.l0.fts  333.3689  333.4588
20220901.204836.92.ucomp.1074.l0.fts  333.3274  333.5365
20220901.204910.52.ucomp.1074.l0.fts  333.3716  333.4944
20220901.204944.14.ucomp.1074.l0.fts  333.2432  333.4879
20220901.205017.75.ucomp.1074.l0.fts  333.2931  333.5312
20220901.205051.35.ucomp.1074.l0.fts  333.2357  333.4131
20220901.205124.94.ucomp.1074.l0.fts  333.3686  333.5468
20220901.205158.54.ucomp.1074.l0.fts  333.3589  333.5166
20220901.205232.14.ucomp.1074.l0.fts  333.3643  333.5371
20220901.205305.73.ucomp.1074.l0.fts  333.2844  333.4765
20220901.205339.33.ucomp.1074.l0.fts  333.2723  333.494
20220901.205412.94.ucomp.1074.l0.fts  333.2163  333.4465
20220901.205446.55.ucomp.1074.l0.fts  333.3629  333.4273
20220901.205520.14.ucomp.1074.l0.fts  333.2953  333.5559
20220901.205553.74.ucomp.1074.l0.fts  333.346   333.5483
20220901.205627.34.ucomp.1074.l0.fts  333.2811  333.5605
20220901.205700.94.ucomp.1074.l0.fts  333.2147  333.397
20220901.205734.53.ucomp.1074.l0.fts  333.2639  333.4092
20220901.205808.12.ucomp.1074.l0.fts  333.3618  333.4564
20220901.205841.70.ucomp.1074.l0.fts  333.2859  333.5335
20220901.205915.29.ucomp.1074.l0.fts  333.2553  333.4444
20220901.205948.87.ucomp.1074.l0.fts  333.2667  333.4084
20220901.210022.45.ucomp.1074.l0.fts  333.3686  333.5047
20220901.210056.05.ucomp.1074.l0.fts  333.313   333.5725
20220901.210129.67.ucomp.1074.l0.fts  333.3439  333.5315
20220901.210203.26.ucomp.1074.l0.fts  333.2782  333.5212
20220901.210236.86.ucomp.1074.l0.fts  333.344   333.4285
20220901.210310.44.ucomp.1074.l0.fts  333.1861  333.473
20220901.210344.02.ucomp.1074.l0.fts  333.1594  333.3589
20220901.210417.61.ucomp.1074.l0.fts  333.2048  333.3949
20220901.210451.19.ucomp.1074.l0.fts  333.3269  333.5114
20220901.210524.77.ucomp.1074.l0.fts  333.344   333.4965
20220901.210558.36.ucomp.1074.l0.fts  333.3181  333.5795
20220901.210631.95.ucomp.1074.l0.fts  333.2945  333.5408
20220901.210705.55.ucomp.1074.l0.fts  333.2913  333.6061
20220901.210739.17.ucomp.1074.l0.fts  333.287   333.4839
20220901.210812.75.ucomp.1074.l0.fts  333.2937  333.536
20220901.210846.34.ucomp.1074.l0.fts  333.278   333.5558
20220901.210919.94.ucomp.1074.l0.fts  333.2651  333.4846
20220901.210953.53.ucomp.1074.l0.fts  333.3494  333.4418
20220901.211027.14.ucomp.1074.l0.fts  333.3383  333.534
20220901.211100.72.ucomp.1074.l0.fts  333.368   333.5871
20220901.211134.32.ucomp.1074.l0.fts  333.2691  333.5544
20220901.211207.90.ucomp.1074.l0.fts  333.2986  333.5497
20220901.211241.48.ucomp.1074.l0.fts  333.2498  333.442
20220901.211315.05.ucomp.1074.l0.fts  333.2459  333.415
20220901.211348.63.ucomp.1074.l0.fts  333.3481  333.5309
20220901.211422.20.ucomp.1074.l0.fts  333.3271  333.5162
20220901.211455.78.ucomp.1074.l0.fts  333.3947  333.5872
20220901.211529.36.ucomp.1074.l0.fts  333.2531  333.4883
20220901.211602.95.ucomp.1074.l0.fts  333.2958  333.4916
20220901.211636.53.ucomp.1074.l0.fts  333.2632  333.4864
20220901.222919.77.ucomp.1074.l0.fts  333.3089  333.5826
20220901.223152.12.ucomp.1074.l0.fts  333.3156  333.6203
20220901.232814.03.ucomp.1074.l0.fts  333.2545  333.5741
20220901.233046.38.ucomp.1074.l0.fts  333.263   333.5975
20220902.000615.08.ucomp.1074.l0.fts  None      None
20220902.000847.44.ucomp.1074.l0.fts  None      None
20220902.004837.39.ucomp.1074.l0.fts  332.6706  333.1913
20220902.005109.76.ucomp.1074.l0.fts  332.721   333.207
20220902.020509.98.ucomp.1074.l0.fts  332.5304  333.2057
20220902.020742.34.ucomp.1074.l0.fts  332.4765  333.2
20220902.024313.36.ucomp.1074.l0.fts  332.4832  333.2203
20220902.024545.71.ucomp.1074.l0.fts  332.5527  333.2444
20220902.032124.05.ucomp.1074.l0.fts  332.7362  333.4848
20220902.032356.48.ucomp.1074.l0.fts  332.6819  333.46
20220901.213815.00.ucomp.1074.l0.fts  None      None

[bberkeyU]

It looks like whatever is happening, it is happening more to RCAM. It is crude but I think I see a parabola or some other curve from sunrise to sunset in both cameras, with the largest radius at noon and a slightly smaller radius as the spar points toward the horizons. But afternoon RCAM seems to have a sharper drop-off in radii where TCAM stays flatter.  

I think we need to look at some more days to see how this behavior holds over time. If no one beats me to it I will take a look tomorrow.

[bberkeyU]

I have produced zoomed-in plots of the rcam and tcam radii and the rcam-tcam across the whole mission.

For the most part, on short days, the plots look noisy. But on longer days, we see the waves program a quick rise in occulter diameter, seen in green and red dots. And the differential change of occulter diameter between the two over the day, with the blue dots (rcam-tcam) almost always falling off with time.

UCoMP occulter radius vs time print version.pdf

[StevenTomczyk]

If the occulter radius is increasing by 0.3 pixels out of a radius of 340 pixels, then delta R / R = 8.8e-4. The expansion coefficient of aluminum is 21e-6 / C. 8.8e-4 / 21e-6 = 42C temperature change required to cause this.

Please check my math, but this sounds entirely plausible. The occulter gets very hot.

[mgalloy]

@bberkeyU Can you make a new issue with the specifics of what needs to be done for the above discussion now?

[mgalloy]

New issue to continue analysis is #216.