| WHEN | WHO | WHAT | |
| 1 | 04.12.00
2044 |
RZ
AJB |
Problem: position-dependent "spikes"
which may be related to wobbler
This scan was a map of M31 with 65" wobbler throw. The MOPSI plot of the rms in each channel vs. the rms in channel 1 revealed that certain channels (8,9,11,18,20,30,31,35?,36?) had "spikes" which were a fixed amplitude above the main correlation, while others (14,15,16,17,33?) had spikes which were the same fixed amplitude below the main correlation. Other properties of these spikes: (a) they are only seen in Plane 2 (i.e., for one of the two wobbler positions); (b) they are smaller in amplitude than the sky noise; (c) the MOPSI sky noise routine can eliminate them. The channels with "positive" spikes are clustered at one edge of the array, while those with "negative" spikes are clustered at the opposite edge. The line connecting these two edges was parallel to the chop direction for the orientation of the array on M31 at the time. The same behavior is seen in other scans on M31. Solution: None yet, but it would be nice to see if this phenomenon goes away for smaller wobbler throws, as we might expect if there is some optical problem related to the wobbler... |
| 2 | 04.12.00
2020 ff. |
AJB | Problem: heterodyne-to-bolometer switch
problems
After switching from heterodyne to bolometer mode, the RED window kept crashing and various scans (P, BT) kept hanging. Solution: Exit OBS, and after re-entering make sure that you begin by invoking @WSTART and @WBOLO (@LAST alone is not enough). |
| 3 | 04.12.00
2007 ff. |
FB
AJB |
Problem: bolometer-to-heterodyne switch problems
After switching from bolometer mode to heterodyne mode, a pointing scan on Mercury produced complete garbage on the screen. Also, the frontend process got lost with the beginning of every scan! Solution: Raw data were coming in correctly, but display and output in RED window were screwed up. OBS code fixed by AS concerning the display, but not yet for the front end process? To restart front end process, on the vax STOP MRT_FE and then FEP -- but let the operator do this. |
| 4 | 02.12.00
1202 |
FB | Problem: VAX/BOGLE conflict
VAX crashed due to conflict with BOGLE after test of ABBA. Solution: Be careful always to restart BOGLE when the VAX crashes or the backend is changed. |
| 5 | 02.12.00
1688 |
FB | Problem: long slews cause loss of initial
data in next scans
Initial data points were missing for this point scan (point had to be repeated). This happened after a long slew, which is also the case for similar glitches at scans 1764, 1766, etc. Solution: None yet. |
| 6 | 02.12.00
1763, 2086-2089 |
AJB
RZ, FB |
Problem: same LST assigned to different subscans
The fifth subscan of 1764 was assigned to the same LST as the fourth subscan. This produced an error message in the RED window: "W-REDBOLOTIP, Warning: Fit may be bad, IFAIL = 5" . A similar (silent) error is seen in numerous scans of other types... E.g. in pointing 2086-2089 the first subscans get messed up. Solution: None yet. The skydip error message at least showed up again on 04.12 scan 1941. |
| 7 | 30.11.00
1349 |
FB | Problem: elevation jump
Elevation jump in data during a map of Venus. Possibly related to problem 6. Solution: None yet? |
| 8 | 03.12.00
1884 |
FB | Problem: missing subscan which wasn't even
written to VAX
Focus scan was not reduced because a subscan was missing; no data existed for this subscan on the VAX, either! Solution: None yet. |
| 04.12.00 | FB | Problem:
160; 1 MSX2
SIO(5-4) IRAM-30M-B34 0.0
0.0 Eq 2249
Solution:
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| N | 30.02.01
ln(2) |
XYZ | Problem: example
You can use this entry (with its own associated plot) as a template: ALT-C to copy it, ALT-V to paste it. Solution: If this example problem were unsolved it would have been highlighted in red. |
Key to initials:
AJB = Andrew Baker
AS = Albrecht Sievers
FB = Frank Bertoldi
RZ = Robert Zylka