|Aug 20, 2009
||GATS publishes the paper "High precision refraction measurements by solar imaging during occultation: results from SOFIE" in Applied Optics. This paper describes the extraordinary refraction angle measurements obtained from the Solar Occultation For Ice Experiment (SOFIE) that permit determination of refraction angles with a remarkable precision of +/- 0.02 arcsec. The technique, which is free of instrument attitude uncertainty, allows temperature sounding up to the lower mesosphere.
|Jan 22, 2009
||GATS wins NASA SBIR contract to develop new trace gas detection system. This work, being carried out in collaboration with the Space Dynamics Lab, could result in the most sensitive device ever for remote detection and measurement of trace gases near the Earth's surface. Applications include monitoring greenhouse gas concentrations from space, detection of natural gas or other emissions using ground based sensors, and even mapping methane distributions on Mars, a possible signature of biological activity.
|May 24, 2008
||SOFIE's first PMC measurement of the season! A PMC was detected at latitude 68.7N, longitude 278.7 thus beginning the second season of northern hemispheric measurements. As the season progresses, comparisons will be made to previous seasons to help determine cloud morphology and how the clouds are impacted by global climate change.
|April 25, 2008
||HALOE V20 - Work has begun on the final improvements to the HALOE Level 1/2 algorithms. These improvements will constitute the last processing of the HALOE data and will include tropospheric water measurements, upgrades in spectral line parameters, altitude registration refinements, and other code advances that will update the HALOE data set for more meaningful comparisons to newer measurements.
|March 25, 2008
||SOFIE data validation and release of data to the public begins. The SOFIE data collected since launch covering both northern and southern hemispheric PMC seasons was reviewed and released to the public; this data is available at the SOFIE web site. SOFIE measurements will provide new insights into atmospheric processes at upper mesospheric/lower thermospheric altitudes.
GATS was granted a patent for a technique that can be used to determine refraction using two celestial light sources. Various methods, both passive and active, can be used to capture an image of the two sources as the line-of-sight vertically transverses though a refractive portion of the atmosphere. Each image sample provides the apparent angular distance between the two light sources. This angular separation as a function of time can be used to determine refraction angle profiles. The technique is unaffected by sensor platform motion and does not require knowledge of atmospheric extinction (absorbing gases, etc.). This system has a range of applications including the use of satellites to obtain precise refraction angle measurements on a global scale. These profiles can be used in deriving/retrieving atmospheric temperature and pressure profiles.
This technique is protected under patent #: US 7,265,820 B1
|July 16, 2007
||SOFIE was placed in autonomy mode.
Because of uplink communication issues, the GATS team outlined
a software algorithm that would enable the instrument to automatically
perform certain tasks
critical to continuing the mission. This software was coded
by SDL, loaded into the instrument, and is now used to calculate
event execution times thus eliminating the need for regular
|May 14, 2007
||SOFIE cover deployed.
The protective door which shielded SOFIE during launch has
been successfully removed. The instrument is now ready for
science measurements! Over the weeks ahead, the GATS team
will use the initial measurements to characterize and calibrate
the instrument, and begin applying the algorithms to produce
the science data products.
|April 25, 2007
Successful launch of the AIM
Satellite! The AIM spacecraft was inserted perfectly
into low-Earth orbit by a Pegasus-XL rocket, dropped from
an L-1011 aircraft out of Vandenberg AFB. Checkout procedures
are underway and all systems appear nominal. Science measurements
will commence in two weeks. GATS designed and operates the SOFIE instrument,
and will process and analyze the important science data
from this experiment.
View the NASA
AIM Press Kit
||Spectral Calculator given a new
home at www.spectralcalc.com.
This is an extremely useful tool for researchers, teachers
and students. Capabilities have increased steadily since the
spectral calculator was first released last year. New options
include a multi-cell setup, a solar position calculator, GEISA
databases, an atmosphere browser, a blackbody calculator and
a unit converter.
||HALOE V19 software archive concluded.
This is a major step in the close out of the HALOE
mission. A complete "snapshot" of the HALOE
processing system has been archived and contains the software,
files, runstreams and other pertinent information. This information
was delivered to the HALOE Project Scientist and to Goddard
||Beta version of the spectral calculator
released at www.gats-inc.com.
This site offers a user-friendly tool for fundamental spectral
calculations. With a simple user-friendly interface, LINEPAK
quickly and accurately calculates spectra and provides a graphical
presentation as well as the actual data.
||At approximately 6:02 a.m. EDT,
the Delta II rocket carrying the CALIPSO and CloudSat satellites
was launched from Vandenberg Air Force Base, California. The
two satellites will circle approximately 705 kilometers above
Earth in a sun-synchronous polar orbit. Their technologies
will enable scientists to study how clouds and aerosols form,
evolve and interact. The GATS flight operations team and flight
software developers are monitoring and controlling CALIPSO,
and providing support during the commissioning phase. More
information can be found at http://www.nasa.gov/mission_pages/calipso/main/index.html.
||The Halogen Occultation Experiment
(HALOE) has now ended its mission after 14 years of flawless
operation. Due to battery failure, the UARS (Upper Atmosphere
Research Satellite) was turned off. In the weeks prior to
the termination of the mission, we conducted a suite of carefully
planned tests to benchmark instrument performance. These tests
will be analyzed to determine if there are any changes in
instrument characteristics since launch.
||SABER version 1.06 software processing
began. The new software includes a large number of improvements
over version 1.05, including interleave averaging, correction
for detector memory effect, correction of off-axis solar scatter,
CO2 line mixing, improved pressure registration, updated Tvib
models, improved Tk resolution, further use of MSIS, updated
O2 Airglow, improved Photolysis Rates, and new O models.
GATS patents include a calibration technique for infrared sensors that provides for long-term calibration of response (signal/radiance) without the need for an onboard reference source. Infrared sensing devises such as orbiting instruments must be calibrated throughout their mission lifetime to permit the determination of critical long-term trends in the quantities that they measure. Typically, an onboard calibrated reference emission source must be used along with special optical viewing paths; this source must exhibit long-term stability from the time that it is built, through launch, and on through a long term mission. GATS has developed a technique to calibrate certain types of these instruments without the need for such an onboard reference.
The basic requirement for this technique is that the device be in orbit about a celestial body (for example, the earth, mars, etc.) having an atmosphere and a known gravitational field. The device must view the limb region of the atmosphere with a plurality of spectral bandpass regions. The radiance emissions in each bandpass are due primarily to the gases in the atmosphere limb region. These gases must have a known mixing ratios as a function of atmospheric pressure, cause spectral opacity to be different in each bandpass, and, for at least one bandpass, the spectral opacity must be non-linearly proportional to the concentrations of the gases in the atmosphere limb region over some portion of the signal profile. The temperature/pressure profile is first determined using a differential technique that is insensitive to calibration constant errors. This temperature profile is then indicative of the absolute radiance emission from the limb and can be used as a calibrated external source for calibrating the instrument response.
In summary, this technique permits accurate calibration without the need for any onboard reference and without the need for the time or equipment required to develop and install the reference in the instrument. There are no requirements for the instrument to look in special viewing configurations and the calibration can be done during the instrument's normal viewing.
This technique is protected under patent #: US 6,294,785 B1