Description

Page : 572

Sondrestrom Lidar Operation Log

Operator(s) : A.Merkel, E.Guðmundsson
Purpose : NLC detection and routine data taking
Date(s) : 000617 - 000618
File(s) : L6170 - L6171
Comments : Started the system up early today. The skies had a lot of high cirrus. Data taking
started with low count rate high background as seen on the 16th. So adjusted
halfwave plates to see if we could improve the signal. We improved it from 1000
counts to 1700 counts. The daystar still needs to be checked to see if we can
optimize the count rate again, but the clouds cover is too dense to do that today.
The maximum count rate that we have seen with the daystar in is 2500.

The clouds went away around 1:00 am GMT. There was a weak signal around 85
km from 2:00 am to around 4:00 am. It could only be seen on the integrated plot
but it definitely could have been a NLC.

The rayleigh signal looked good without clouds. It was behaving very well after
the
halfwave plates were readjusted

Good data set!
Logfile : l0006170.log

Setup:0

Page : 573
[Variables]
Dye Power=105 mJ
Rayleigh Power=510 mJ

[0]
Iris=min_opening
Rayleigh System=On
Dye System=On
Daystar=In
Polarizer=In
HalfWave Plates=In
Rayleigh Filter=2:532(.5nm)

Logsheet:0

Page : 574

Sondrestrom Lidar Operation Log

Log Sheet 1 of 1
Operators : A.Merkel, E.Guðmundsson
Date(s) : 000617 - 000618
File(s) : L6170 - L6171

Files	Time [UT]	Comments	Cnt	S	Ope
L6170	19:52:53	Start of experiment	1062	0	AM
L6170	19:53:54	starting pretty early. There are lots of high cirrus clouds	763	0	AM
L6170	19:56:58	Sodium Convergence mirror adjusted	823	0	AM
	20:00:12	The count rate of the Rayleigh channel looks very low.		0	AM
		Going to try to figure out what has changed, starting with
		halfwave plates. Background looks right for sza=60, b=300
L6170	20:13:57	adjusting halfwave plates	1258	0	AM
L6170	20:42:10	end adjustment	1553	0	AM
L6170	20:48:35	Sodium Convergence mirror adjusted	1480	0	AM
L6170	20:48:45	thick cirrus moving in	1480	0	AM
L6171	20:52:27	incremented file	1449	0	AM
L6171	20:54:52	the count rate looks better after adjustment, without clouds		0	AM
		count rate=1700 and background=300
L6171	20:56:03	sodium channel has no visible sodium layer right now		0	AM
	20:56:02			0	AM
L6171	21:28:16	Starting to see sodium on the integrated profile SZA=68.9	1491	0	EG
L6171	00:28:22	Sodium Convergence mirror adjusted	1705	0	AM
	02:10:22	the Rayleigh count rate looks good, background=21, sza=88.5	2285	0	AM
L6171	03:09:29	!!There is something very weak at 85km on the rayleigh ch.	1985	0	EG
		shows only when integrated for an hour.
L6171	03:13:50	Sodium Convergence mirror adjusted	1876	0	EG
L6171	03:14:30	Dye system tuned to 589.158 nm was at 589.156nm	1830	0	EG
L6171	08:06:54	everything still looks really good sza=75, back=87	2405	0	AM
L6171	09:42:24	End of experiment	2211	0	AM