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5
April 2007: New “red”
higher-bandwidth detector/amplifier modules installed at CHATS.
17 March 2007: CHATS begins
7 March 2007: REAL arrives in Dixon CA for CHATS
5 January 2007: 16"
optics received from Nu-Tek for laboratory
telescope.
Autumn - Winter 2006:
Striving for continuous & unattended operation of REAL v1 from FL-1
parking lot to improve transmitter stability, beam-steering unit
reliability, and develop remote controls. Systematic polarization errors
being reduced.
Summer 2006:
REAL v3 linewidth of < 500 MHz achieved.
Journal article forthcoming.
Summer 2006:
New lidar seatainer and
dedicated air-ride trailer refurbishment begins. These projects funded by
EOL TDF.
March & April 2006:
Deployment in T-REX in Independence
CA. This is its first NSF funded field
deployment.
September 2005:
Deployment in Albuquerque NM
for intercomparison with REAL v2.
18 July 2005: Generated 350
mJ/pulse at 50 Hz at 1.54 microns in the lab.
14 July 2005: Higher 1.5-micron wavelength
power levels achieved in lab: 325 mJ/pulse - 350 mJ/pulse at rep rates between 10
and 25 Hz.
June 2005:
Carpet removed from lidar labs and tile
installed.
June 2005:
Deployment at Dugway Proving Ground, UT, to test
new depolarization capability on aerosol plumes.
5 May 2005:
First backscatter depolarization ratio measurements.
April 2005:
Continuum Powerlite 9050 laser arrives.
Winter & spring 2005
- REAL back inside FL-1 lidar lab. BSU on
roof. Preparing for major system upgrades.
4-22 October 2004
- Deployment of REAL at Dugway Proving Grounds, Utah.
Summer 2004 -
REAL operates from seatainer located east of FL-1
in Boulder.
2-9 May 2004 -
REAL's first field deployment: Washington, D. C.
22 April 2004 - REAL makes it first
scans with BSU from seatainer located east of
FL-1.
Early April 2004:
Currently moving the entire system to the lidar seatainer and completing beam steering unit. Preparing for May field experiment.
March 2004:
Manuscript on REAL accepted to Applied Optics. To appear in print summer
2004.
March 2004:
1" thick Zerodur beam steering unit mirrors
acquired.
14 January 2004: Pump laser repaired. Pockels cell heater was broken.
early January 2004: Beam-steering
unit almost finished. Searching for new source of flat mirrors.
mid-December 2003 - present: Surelite III pump laser problem (free-lasing) stopped
project. Currently working with laser vendor to correct problem.
Early Dec. 2003:
Determined experimental composite mirrors not sufficiently flat.
20 November 2003: Experimental composite mirrors for beam-steering unit have been
glued up.
Early November 2003:
4'x4'x4" optics table received for seatainer. Will begin consolidating prototype for
compact configuration.
October 2003:
17" diameter beam steering unit being
designed and constructed to enable scanning. Planning to move the system
into the lidar seatainer for mobile operation.
8-12 Sept 03: New custom telescope installed. First data
collected with new telescope on September
17.
28 Aug. 03:
New custom telescope arrived from OMI. 16"
parabolic primary and flat
secondary have gold coated optics for high reflectivity in the NIR.
Aug 14: Wheel
fan in gas cell replaced with series of 8 box fans. Much better circulation
of methane results in very steady beam profile. Resume collecting data each
day at 10 Hz.
Aug 03: We
collected over 77 hours of observations at 1.5
microns over 15 different days between July 10 and August 5. On August 5 we
burned a mirror and window in the Raman cell. We are currently
investigating the cause or the burn and
replacing the Raman cell squirrel
cage fan with an aray of 8 box fans for better methane
circulation. We think that better circulation will allow us to operate at
higher pulse repetition rates. Our best operation is at 5 Hz now and we
hope to get better performance at 10 Hz. Our long term goal is 100 Hz.
July 03: Laboartory prototype system successfully developed.
Initial project goals demonstrated. We collect data now from the lab
whenever possible and are working on design/development of a fieldable system with beam steering unit.
16 July 03:
Received erbium fiber amplifier to increase
power of diode injection seed of Raman cell.
11 July 03:
First horizontal pointing test. Detected returns from 6 km. See results on eye-safe lidar observations
webpage.
2 July 03:
First attempt to use the 200 micron InGaAs APD in
1543 channel. See results on observations page. Now waiting for new
telescope and software upgrades.
23 June 03:
Waiting to install InGaAs APD and linear amp for
1543 channel. Also working on faster data acquisition computer and energy
normalization.
11 June 03:
Raman cell back up and running with (1) new mirror, (2) all fan bearings
replaced with non-lubricated ones, (3) one new window, and (4) all fan
shrouding removed for better mixing.
28 May 03:
Burned internal Raman cell mirror.
22 May 03:
First transmit & receive at 1064 & 1543 simultaneously using InGaAs PIN (1543) and LiCEL
Si APD (1064). Transmitted about 250 mJ/pulse
in both channels.
16 May 03:
Ready to test entire transmit & receive system. NewFocus
PIN detector died. Waiting for replacment.
14 May 03: Surelite III returned and working again.
8 May 03: Surelite III shipped back to factory for overhaul.
1 May 03: Surelite III Pockels cell
replaced this week. Dual-channel receiver in place. Able to transmit 175 mJ/pulse at 10 Hz of 1543.7 nm.
2 April 03:
Raman cell windows replaced (solid windows), leaks fixed, pressure tested
and on the table with 200 PSI of methane. First 1.5 micron light observed
today.
Early Feb. 03:
A beam-expander has been constructed and all the transmit optics are in place.
The Raman scattering gas cell was delivered on 13 Jan. 2003. Unfortunately, we burned an
exit window with the YAG and don't have a replacement on hand. The cell
windows are made from two optically contacted pieces and therefore are
expensive and require about one month to deliver. We are considering using
windows made only from one piece.
In addition to transmitter work, we have ordered a 16" diameter
gold-coated primary as the first piece for a new telescope. We continue to
work with the 16" Meade.
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