Description


Page : 1071

Sondrestrom Lidar Operation Log


Operator(s) : E.Guðmundsson
Purpose : Test data aq for caracterizing Rayleigh channel PMT afterpulsing.
Date(s) : 021017 - 021017
File(s) : L20021017_000 - L20021017_001
Comments : Taking test data as requested. This is to try and analyse and caracterize the PMT
afterpulsing that has been observed lately.

Dye laser off line due to maintenance.

A problem started to appear arround 03:12. Did not recover from that. Problem
traced to SR430 BNC signal input. Test eneded prematurely due to this.
Logfile : l0210170.log

Setup:0


Page : 1072
[Variables]
Dye Power=95mJ
Rayleigh Power=480mJ

[0]
Iris=1mm
Rayleigh System=On
Dye System=Off
Etalon=Out
Daystar=Out
Polarizer=In
HalfWave Plates=Tracking
Rayleigh Filter=2:532(.5nm)
Rayleigh seeding=off

Logsheet:0


Page : 1073

Sondrestrom Lidar Operation Log


Log Sheet 1 of 1
Operators : E.Guðmundsson
Date(s) : 021017 - 021017
File(s) : L20021017_000 - L20021017_001
FilesTime [UT]CommentsCntSOpe
L20021017_00000:35:51Start of experiment0
Taking data with the 35km chopper setting before moving
chopper up to ~75km
00:53:53Stopping data aq to move chopper up to 75km0
00:58:59taking data aqaing with chopper at 75km0
01:48:29Bad record, looks like the sr430 has triggered at a wrong 0
time or there is a phase problem with the chopper?
01:53:18there is is again, same symptom??0
02:01:20Bad record again!0
02:24:02pausing data aq to change convergence. Simulating 0
the normal 35km countrates at a lower altitude for
extraction of afterpulsing error contribution to counts.
02:45:02Have had difficulties in converging......data up to now now0
good (from 02:24)
02:52:57Doing better now....taking data with the current setting0
03:12:46Counts starting to drift...checked outside...the sky is clear.0
L20021017_00103:22:50There is something wrong. Signal has fallen a lot and noise0
is starting to creap in. The sky is not at fault.
03:37:26Now the signal is all but gone....data no good. 0
03:38:33trouble shooting0
03:55:01Looks like a problem with the SR430 BNC input again..0
03:59:12Ending test prematurely due to the fault.0
04:00:24End of experiment0