NASA GES Satellite Data

The Earth Observing System is a major component of NASA's Earth-Sun System Missions. The mission has three components: a. a coordinated series of polar-orbiting and low inclination satellites for long-term global observations of the Earth’s biosphere, including the land surface, atmosphere, oceans; b. a data system supporting them; and c. a science component. The 2D and 3D geospatial imagery at the GES DISC are being integrated into Google Earth to augment their scientific value.

Two-dimensional flat satellite data

Currently, 2D flat satellite data from TRMM and Aqua satellites separately are integrated into Google Earth for synergistic visualization and research.

On TRMM, there are five instruments on the satellite (NASA 2007a): a Precipitation Radar device, a Microwave Imager, a Visible Infrared Scanner, a Cloud and Earth Radiant Energy measuring device, and a Lightning Imager. Data from these instruments are processed for rendering on Google Earth. The core geophysical parameters represented in the data include rain rate; rain frequency; mean surface rainfall; rain rate probability distribution; cloud liquid water; rain water, and so on. The temporal range of the data products is from December 1997 to present. The spatial range covers all longitudes but emphasis is mainly on latitudes between 40°N and 40°S (NASA 2007b).

The Aqua spacecraft detects water in all its forms -- liquid, solid, and vapor -- throughout the atmosphere and both on and near the earth’s surface. The Atmospheric Infrared Sounder (AIRS) instrument on Aqua produces global coverage data twice daily that describes atmospheric temperature and humidity, land and sea surface temperatures, clouds, and radioactive energy flux (Pagano 2003). The gridded level 3 daily and monthly standard products are processed and visualized by Google Earth. The described physical parameters include total integrated column cloud liquid water; total integrated column ozone burden; surface air temperature; surface skin temperature; mean surface pressure; outgoing long-wave radiation flux; and combined cloud top temperature.

In addition to the above, Ozone Monitoring Instrument data from Aura, MODIS data from Terra and Aqua, and Advanced Microwave Scanning Radiometer data from Aqua are analyzed, processed and served via (Giovanni 2007b) and finally visualized in Google Earth. User can specify spatial and temporal range, physical parameters, plots methods, etc.

Three-dimensional vertical satellite data

Four kinds of 3D satellite data are rendered in Google Earth for synergistic scientific research: CloudSat, CALIPSO, AIRS and MODIS-Aqua data. All data are first processed through Giovanni version 3 system (Giovanni 2007a) , then visualized as an orbit curtain in Google Earth.

The CloudSat satellite, which was launched by NASA on April 28, 2006, and which has been collecting data since June 2, 2006, records vertical profiles of clouds. The profiles provide a 3D view of the vertical structure of clouds from the top of the atmosphere to the surface and the radar observations are processed into estimates of water and ice content with 500m vertical resolution (Partain 2006). The data are made available in the format of Hierarchical Data Format for Earth Observation System (HDF-EOS).

The CALIPSO satellite employs an innovative set of instruments to explore our atmosphere and to study the aerosols and thin clouds that play a major role in regulating earth’s weather, climate, and air quality. It collects data about the vertical structure of clouds and aerosols unavailable from other earth-observing satellites. CALIPSO globally surveys the vertical distribution of aerosols and clouds in the atmosphere, and optical and physical properties of aerosols and clouds (NASA 2005). On CALIPSO, there are loaded three co-aligned, near-nadir viewing instruments: a 2-wavelength polarization-sensitive lidar, an imaging infrared radiometer, and a high-resolution wide field camera. The lidar profiles provide information on the vertical distribution of aerosols and clouds, cloud particle phase, and classification of aerosol size (NASA 2006).

AIRS and MODIS-Aqua also provides vertical profiles of quantities such as atmospheric temperature, H2O saturation, and of H2O vapor. AIRS measurements of the Earth’s atmosphere and surface allow scientists to improve weather predictions and observe changes in Earth’s climate. Much of the data from MODIS includes 3D features of the land, oceans, and atmosphere, which will improve our understanding of dynamics global processes (NASA 2007c).