The long-term goal of this activity is to demonstrate the feasibility of a laser sounder instrument capable of measuring the surface-pressure field for the entire air column from satellite-to-ground with global coverage. The earth's surface pressure is a vital component of a variety of important scientific measurements, which are being undertaken at Goddard. Accurate knowledge of the surface pressure can enable calibration of 2-D measurements of CO2 content in the atmosphere and greatly improve the fidelity of surface water redistribution measurements from time-varying gravity fields. It is also important in weather prediction and atmospheric modeling.
The Cloud Physics Lidar (CPL) is a backscatter lidar designed to operate simultaneously at three wavelengths: 1064, 532, and 355 nm. The purpose of the CPL is to provide multi-wavelength measurements of cirrus, subvisual cirrus, and aerosols with high temporal and spatial resolution. From the fundamental measurement, various data products are derived, including: time-height cross-section images; cloud and aerosol layer boundaries; optical depth for clouds, aerosol layers, and planetary boundary layer (PBL); and extinction profiles.
The CO2 Boundary Layer Profiler is a ground-based prototype Differential Absorption Lidar. DIAL's measurement technique uses the change in signal strength between a wavelength strongly absorbed by CO2 and one not absorbed at all to make range resolved measurements of CO2.
Surface deformation is linked directly to earthquakes, volcanic eruptions, and landslides. Observations of surface deformation are used to forecast the likelihood of earthquakes occurring as a function of location, as well as predicting both the place and time that volcanic eruptions and landslides are likely. Advances in earthquake science leading to improved time-dependent probabilities would be significantly facilitated by global observations of surface deformation, and could result in significant increases in the health and safety of the public due to decreased exposure to tectonic hazards. Monitoring surface deformation is also important for improving the safety and efficiency of extraction of hydrocarbons, for managing our ground water resources, and, in the future, providing information for managing CO2 sequestration.
GLAS (the Geoscience Laser Altimeter System) is the first laser-ranging (lidar) instrument for continuous global observations of Earth. From aboard the Ice Cloud and Elevation Satellite (ICESat) spacecraft, it makes unique atmospheric observations, including measuring ice-sheet topography, cloud and atmospheric properties, and the height and thickness of radiatively important cloud layers needed for accurate short term climate and weather prediction.
Fiber lasers and fiber-amplifiers are truly an enabling technology for NASA's space flight remote sensing applications. Fiber lasers and fiber-amplifiers are light, compact and efficient, however work is still required on power-scaling and pulse-energies for NASA-specific applications, such as altimetry and atmospheric spectroscopy. Fiber lasers and amplifiers offer numerous advantages for both near-term and future deployment on instruments on Earth Science Remote Sensing orbiting satellites.
The Laser Remote Sensing Laboratory at NASA's GOddard Space flight Center is developing near-infrared photon-counting detectors for the CO2 sounders on ASCENDS and for multi-beam swath mapping laser altimeters for the Lidar Surface Topography (LIST) mission.
We are developing a laser-based sounding approach for remotely measuring the global concentration of atmospheric CO2 from a satellite. In our method, CO2 abundance is measured by using a three-channel nadir viewing lidar in a 550 km altitude dawn dusk orbit. The CO2 measurement is made utilizing the strong laser echoes from the surface as the lasers are rapidly tuned on and off a selected CO2 line in the overtone band near 1570 nm. A similar technique is used simultaneously on a second channel to measure the surface pressure by utilizing a line in the oxygen A band near 770 nm. The dry-air mixing ratio can be calculated from the ratio of CO2 to O2, that can be measured using a similar technique applied to a line in the O2 absorption band at 770 nm. A third channel operating at 1064 nm is used to detect and screen measurements influenced by cloud and aerosols in the path.
NASA's Laser Vegetation Imaging Sensor( Land, Vegetation, and Ice Sensor) or LVIS, is a scanning laser altimeter instrument that is flown, by aircraft, over target areas to collect data on surface topography and vegetation coverage. The LVIS, which also includes data from an integrated inertial navigation system (INS) and global positioning system (GPS), is designed, developed and operated by the Laser Remote Sensing Laboratory, at Goddard Space Flight Center.
The Lunar Orbiter Laser Altimeter (LOLA) will provide a precise global lunar topographic model and geodetic grid that will serve as the foundation of essential lunar understanding. This will aid future missions by providing topographical data for safe landings and enhance exploration-driven mobility on the Moon. LOLA will also contribute to decisions as to where to explore by looking at the evolution of the surface.
The objective of the Lunar Reconnaissance Orbiter (LRO) Laser Ranging (LR) system is to enable the spacecraft to achieve its precision orbit determination requirement. The LR will make one-way range measurements via laser pulse time-of-flight from Earth to LRO, and will determine the position of the spacecraft at a sub-meter level with respect to Earth and the center of mass of the Moon. Ranging will occur whenever LRO is visible in the line of sight from participating Earth ground tracking stations.
The Mars Orbiter Laser Altimeter (MOLA) is one of the major instruments that was part of the Mars Global Surveyor (MGS) spacecraft. MGS launched on November 7th, 1996 and traveled three-hundred-and-nine days to enter Mars' orbit on September 12, 1997.
MOLA studies the planet's geophysics, geology and atmospheric circulation in addition to acting as a passive radiometer (climate applications of satellite data). MOLA was able to make the most accurate global topographic map of any planet in the solar system. It also captured the seasonal variations in snow depth on the planet, its internal structure and pathways of past water flows and watersheds. MOLA's last data collection was on June 30th, 2001.
MLA is one of the primary instruments on NASA's MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) Project. MLA's function is to create topographic maps of Mercury that will help characterize the geologic history of the planet. The MESSENGER is the first spacecraft to orbit Mercury; the solar system's most unexplored planet.
The mini-LHR is a suitcase-sized instrument that measures greenhouse gases in the atmosphere. Targeted gases include carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and nitrous oxide (N2O), as well as oxygen (O2) for a measure of atmospheric pressure. These low-cost instruments will ultimately form a global network of ground sensors that can provide column concentrations as well as altitude profiles.
The MMLA is a proof-of-concept instrument designed to demonstrate the application of a patented single photoelectron level laser ranging method, developed by GSFC's SLR program, to imaging laser altimetry. This ranging method treats all photon events, both random background noise and signal, as potentially valid during the acquisition phase.
Satellite Laser Ranging (SLR) is a fundamental measurement technique used by the NASA Space Geodesy Program to support both national and international programs in Earth dynamics, ocean and ice surface altimetry, navigation and positioning, and technology development. NASA continues to maintain and operate five trailer-based Mobile Laser Ranging Stations (MOBLAS) and two compact Transportable Laser Ranging Systems (TLRS) at fixed sites.
The Next Generation Satellite Ranging System (NGSLR) network is intended to be an autonomous, eye-safe, sub-centimeter precision ranging instrument capable of tracking a wide range of cube corner equipped satellites up to twenty thousand kilometers altitude.
Satellite Laser Ranging (SLR) provides fundamental data used in establishing and updating the Terrestrial reference Frame. This Earth-centric, fixed coordinate system, and its connection to the celestial coordinate system, are essential to successful communication, operation, and navigation of a host of NASA satellites and interplanetary probes.
Simplesat was an engineering experiment in the form of a small satellite. Its goal was to try to determine whether an inexpensive satellite could be constructed from commercial parts and survive in orbit.
The Laser Remote Sensing and the Planetary and Geodynamic Laboratories are partnering on the Swath Imaging Multi-polarization Photon-counting Lidar. SIMPL is an airborne prototype that demonstrates laser altimetry measurement methods and components that enable efficient, high-resolution, swath mapping of topography and surface properties from space. SIMPLE is the most efficient way to do laser ranging. It is a push-broom laser altimeter that includes four laser beams, each having a green and near infra-red component. One of SIMPL's major functions is to advance laser altimetry measurements of the cryosphere process in the polar regions.
Haris Risis leads this effort to develop active laser instrumentation that is capable of sensitive remote measurements of atmospheric trace gases from planetary orbit. Such laser-based instrumentation can provide
unprecedented information on planetary atmospheric
composition, chemistry and evolution.
