In a joint effort, the Naval
Research Laboratory (NRL), the USAF Phillips Laboratory, and
NASA have established a new Satellite Laser Ranging (SLR) station
at the USAF Starfire Optical Range (SOR) in Albuquerque, New
Mexico. Returns have been obtained from satellites as low as
370 km and as high as 20,200 km overhead (NAVSTAR GPS).
Dr. G. Charmaine Gilbreath, NRL's
SLR Project Manager and Principal Investigator says, "The
new capability has been developed for precise determination of
satellites and for onboard spacecraft system performance verification.
This is an experimental facility and runs in a `campaign' mode.
Specifically, data on geodetic satellites will be obtained at
intermittent times of the year coincident with special
experiments."
NRL designed, integrated, and
operates the transmit/receive system at SOR. This powerful new
system presents an energy/receiver aperture-to-area Figure-of-Merit
of 2886 mJ-m2. The USAF designed the optical train through the
3.5-meter telescope and provides tracking and acquisition for
the effort. The processing and analysis of scientific data are
performed by NRL. NASA provides technical assistance as
required.
The system comprises a 10 Hz,
300 mJ doubled Nd-YAG laser, with a 250 ps pulse width. The beam
divergence is on the order of 70 to 100 microradians through
the 3.5-meter telescope.
"Non-terminator assisted
and daytime ranging can be performed; however, we are limited
to ranging 1.5 hours before sunset to 1.5 hours after sunrise
at this time due to direct sunlight restrictions on the telescope
itself," says Dr. Gilbreath.
The 3.5-meter telescope combined
with the Micro-Channel Plate-enhanced photomultiplier tube used
for photon detection, and 300 mJ of energy enables the system
to obtain returns from enhanced spacecraft at 22,000 km or
higher.
The receiver subsystem also has
1 GHz and 4 GHz oscilloscopes for waveform detection and signature
analysis. A GPS-steered rubidium clock serves as the master
clock for the telescope and the
Tx/Rx system, which includes externally triggering the laser.
Officially, the site has been
assigned 7884 for a pad marker, 66 for the SLR station ID, occupation
01. The reference point on the 3.5 Meter telescope is: x: 1483442.808
(m); y: -5019625,640 (m); z: 3635692.076 (m). This position was
derived from range data obtained from LAGEOS-1 and is in ITRF-95
epoched 49875.
Dr. Gilbreath adds, "During
May and June 1995, NRL conducted SLR operations at SOR on the
satellites LAGEOS-1, LAGEOS-2, TOPEX, GPS-36, ETALON-1, ETALON-2
and GFZ-1 from the facility. Data for these satellites have been
released to the international network. The data are available
via anon.ftp on cddis.gsfc.nasa.gov."
The U.S. Naval Research Laboratory is the Navy's full-spectrum corporate laboratory, conducting a broadly based multidisciplinary program of scientific research and advanced technological development. The Laboratory, with a total complement of nearly 2,500 personnel, is located in southwest Washington, D.C., with other major sites at the Stennis Space Center, Miss., and Monterey, Calif. NRL has served the Navy and the nation for over 85 years and continues to meet the complex technological challenges of today's world. For more information, visit the NRL homepage or join the conversation on Twitter, Facebook, and YouTube.
Comment policy: We hope to receive submissions from all viewpoints, but we ask that all participants agree to the Department of Defense Social Media User Agreement. All comments are reviewed before being posted.