Description


Page : 813

Sondrestrom Lidar Operation Log


Operator(s) : E.Guðmundsson
Purpose : Installation of light tight box arroundn daystar and validation of receiver. Routine data collection if possible.
Date(s) : 010610 - 010611
File(s) : L106100 - L106102
Comments : Because of work on the rayleigh and the sodium paths some alignment was done
prior to this run. The light tightening arround the daystar was also finalized prior
to the run.

The light tightening does not seem to improve on the S/N when using the daystar
so we should consider using the 532nm filter to improve the SNR and live with
the 30-40% loss in signal..

On the temperature front I have this to report. The temperature in the Harris
room was elavated but manageble as the outside tempertarure went up to 20 deg C.
increasing the flow by ~500cfm should do the trick in keeping the temp under
control during hot days.

The temperature in the Laser room was elevated to max ~28 deg C and therfore
rose above the setpoint of the Rayleigh HG causing it to drift. This rise in
temperature caused a slow drift on the wavelength of the dye laser as well, during
the warmup periode. From the looks of things, the heat problem in the laser
room
is not due to external heating but rather from the small amount of heat generated
in the room not being able to dissipate as the temperature differential between the
inside and outside is small. The actual heat generated by equipment in the room
room is perhaps in the order of 1-2kW. A small capacity AC unit should be able
to
pump the heat out of the room, maybe into the highbay.
Logfile : l0106100.log

Setup:0


Page : 814
[Variables]
Dye Power=83mJ
Rayleigh Power=530mJ

[0]
Iris=min_opening
Rayleigh System=On
Dye System=On
Etalon=Out
Daystar=In
Polarizer=Out
HalfWave Plates=Tracking
Rayleigh Filter=none
Rayleigh seeding=off

Logsheet:0


Page : 815

Sondrestrom Lidar Operation Log


Log Sheet 1 of 2
Operators : E.Guðmundsson
Date(s) : 010610 - 010610
File(s) : L106100 - L106101
FilesTime [UT]CommentsCntSOpe
L10610019:25:00Start of experiment48720
L10610019:40:42Light tight box has been installed arround the daystar46620EG
L10610019:41:13SZA=58.8 S=4767 N=67846620EG
L10610019:43:13UPS! Forgot to change Recs per scan to 600, corrected and 48030EG
incremented
L10610119:43:43Counts48030EG
L10610120:09:02No sodium layer has been observed. The wavelength from the44590EG
wavemeter had drifted to 589.161nm so I tuned it to 589.157nm
to see if the layer starts showing up.
L10610120:12:17A patch of thin clouds above now43890EG
L10610120:30:27Clouds have gone away for the time beeing41670EG
L10610120:54:03Rayleigh Convergence mirror adjusted35690EG
L10610120:57:41Sodium Convergence mirror adjusted35440EG
L10610121:07:40Rayleigh counts have been falling gradually since the detection31890EG
of the clouds above. Bkgnd. noise levels do not seem to be falling
L10610121:17:47The rizing temperature in the laser room caused the HG 31140EG
temperature to rize above the setpoint. tweeked HG to
correct.
L10610122:03:57I'm seeing the sodium signal on the integrated profile and41040EG
it appears as if the Reyleigh equvivalent is ~41km.
L10610122:36:07SZA=75.6 S=4000 N=329 SN~12 Note- there is a slight41050EG
cirrus layer present that is probably degrating the SNR slightly
It looks like the light tightening arround the daystar does not
improve the noise performance. The conclution must be that

Logsheet:1


Page : 816

Sondrestrom Lidar Operation Log


Log Sheet 2 of 2
Operators : E.Guðmundsson
Date(s) : 010610 - 010611
File(s) : L106101 - L106102
FilesTime [UT]CommentsCntSOpe
L10610122:40:16background noise is comming trough the daystar. It might 0EG
improve things if we ran with the 532nm filter cuncurrently
with the daystar.
L10610123:00:42heawy cloud bank approaching34740EG
L10610123:53:47Incremented0EG
L10610123:54:01Rayleigh HG adjusted15470EG
L10610200:03:01Loss of signal due to clouds0EG
L10610200:11:27End of experiment15110EG