Dana, Louis
We analyzed every measurement of the sensing function taken between the start of O4 and October 27th to see if they were reliable and came up with the following, summarized in the table below:
| Report ID | GPS time [s] | Time locked prior to measurement[h] |
|---|---|---|
| 20230504T055052Z | 1367214670 | 6+ |
| 20230505T012609Z | 1367285187 | 5.2 |
| 20230505T174611Z | 1367343989 | 5.2 |
| 20230505T200419Z | 1367352277 | 0.2 |
| 20230506T182203Z | 1367432541 | 4.7 |
| 20230508T180014Z | 1367604032 | 6+ |
| 20230509T070754Z | 1367651292 | 5.8 |
| 20230510T062635Z | 1367735213 | 3.5 |
| 20230517T163625Z | 1368376603 | 6+ |
| 20230616T161654Z | 1370967432 | 3.4 |
| 20230620T234012Z | 1371339630 | 2.9 |
| 20230621T191615Z | 1371410193 | 2.1 |
| 20230621T211522Z | 1371417340 | 4.0 |
| 20230628T015112Z | 1371952290 | 4.8 |
| 20230716T034950Z | 1373514608 | 6+ |
| 20230727T162112Z | 1374510090 | 6+ |
| 20230802T000812Z | 1374970110 | 2.6 |
| 20230817T214248Z | 1376343786 | 6+ |
| 20230823T213958Z | 1376862016 | 4.3 |
| 20230830T213653Z | 1377466631 | 3.7 |
| 20230906T220850Z | 1378073348 | 3.9 |
| 20230913T183650Z | 1378665428 | 6+ |
| 20230928T193609Z | 1379964987 | 6+ |
| 20231004T190945Z | 1380481803 | 4.7 |
| 20231018T190729Z | 1381691267 | 6+ |
| 20231027T203619Z | 1382474197 | 6+ |
Ideally, the detector should be in lock state at least three hours before making a sensing function measurement to make sure the thermalization process is complete. However, there were a couple measurements that were made when the detector had only been locked for about two hours (06/21, 08/02), and there was one particularly problematic measurement that was made when the detector had only been locked for about 10 minutes (05/05). This last measurement should certainly not be included in the GPR calculation.
The code used to obtain the detector lock state and history given a report ID is attached below. Note: To run this code, you will need access to pydarm, so run the following command in the terminal before executing the file: source /ligo/groups/cal/local/bin/activate
report 20230505T200419Z changed to 'invalid' in LHO:75629.