Changes between Version 41 and Version 42 of PublicPages/MayallZbandLegacy/NotesforObservers/Problems
- Timestamp:
- Feb 10, 2016 11:40:17 PM (8 years ago)
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PublicPages/MayallZbandLegacy/NotesforObservers/Problems
v41 v42 5 5 === 0. No images being written === 6 6 7 '''Symptom''': No new images are showing up on disk or in the obsbot display . The control system and readout timer,7 '''Symptom''': No new images are showing up on disk or in the obsbot display, and the real time display does not update. The control system and readout timer, 8 8 however, had no indication that data wasn't being written. 9 9 … … 33 33 - restart the observing script by following the instructions here 34 34 35 === 1. Detector timeouts === 35 === 1. Images appear on the real time display, but are not written immediately to the data directory === 36 37 '''Symptom''': The real time display shows updated images, but files are very slow to appear in the data directory. The MOSSTAT and copilot displays are slow to update; copilot may eventually flag the image with a "readtime" failure. 38 39 '''Frequency:''' Frequent as of early February 2016. 40 41 '''Fix:''' 42 - In the Data Handling System window in the mosaic3:1 VNC session 43 {{{ 44 - select the Shared Memory Cache tab 45 - Click Process All 46 - Click Update Status 47 48 }}} 49 - the image should then appear in the data directory. 50 51 52 === 2. Detector timeouts === 36 53 37 54 '''Symptom''': Count-down timer in NMSL GUI turns red keeps counting down negative numbers (to -105 or so), and no new images are read. … … 52 69 53 70 54 === 2. Images show bad amp ===71 === 3. Images show bad amp === 55 72 56 73 '''Symptom:''' One amp has extremely large noise, looks awful the display of the image with "mcsdisplay" with a noise > 1000 ADU/pix from the "mscstat" command. … … 69 86 - Re-start the observing script 70 87 71 === 3. 4MAPS primary mirror support goes “OFF AIR” during observing ===88 === 4. 4MAPS primary mirror support goes “OFF AIR” during observing === 72 89 73 90 '''Symptom:''' The OA should notice when this happens, but you can also see if the mirror support is listed as "OFF AIR" on the 4MAPS GUI. … … 87 104 - Once the OA has reset 4MAPS, re-start the observing script 88 105 89 === 4. Shifted images ===106 === 5. Shifted images === 90 107 91 108 '''Symptom:''' Sub-blocks of an image have been shifted in the readout, and is obvious on the display as the overscan region being in a different place. … … 107 124 - And add a note to the logs 108 125 109 === 5. Repeat images ===126 === 6. Repeat images === 110 127 111 128 '''Symptom:''' The image data is an exact duplicate of a previous image, usually the one from 6 images prior. … … 137 154 138 155 139 === 6. Focus drifting ===156 === 7. Focus drifting === 140 157 141 158 If you lose track of the focus and don’t know whether you are below or above the focus value, wait for the readout countdown to start … … 165 182 - Restart observing 166 183 167 === 7. Images of stars on the guider are bouncing around ===184 === 8. Images of stars on the guider are bouncing around === 168 185 169 186 '''Symptoms:''' Guider images are visibly bouncing around on the TV guider image, and the seeing is poor, with the image extension being … … 178 195 '''Fix 2:''' If accounting for the wind does not fix the problem, it may be related to an issue of telescope tracking, as was the case in February 8-9 2016. You can try a test of moving to a different part of the sky and taking a 60-second exposure. If the stars are round, but are elongated when you move back to the field, there may not be much you can do other than report the problem and continuing to observe. The problem seen in February 8-9 2016 was traced to the RA axis encoder tape. Shelby Gott cleaned the tape, which fixed the problem. 179 196 180 === 8. Bad telescope pointing ===197 === 9. Bad telescope pointing === 181 198 182 199 '''Symptoms:''' The reported telescope offsets from the python "obsbot" or the IDL "mosstat" show … … 200 217 }}} 201 218 will print out a summary of all the frames from 10001 to the present in a nice tabular form (widen the window). This is useful for checking how the seeing and sky brightness have varied since frame 10001, and whether one should create and upload a new JSON observing script. The /noprint just prevents the decstat output for every frame; if you want to see that, then don't use the /noprint keyword. 202
