Sensors
This section is intended to provide a basic knowledge and understanding about the various sensors used for remote sensing. For simplicity, the following discussions are broken into the two types of sensors systems (active and passive) used in remote sensing.A passive imaging system senses the reflected or emitted radiation of a target (which occurs naturally when the target reflects sunlight or emits thermal energy). These types of sensors are multispectral scanners, radiometers, and spectrometers. The majority of passive systems that are used for remote sensing applications operate in the optical, infrared, and thermal infrared portions of the electromagnetic spectrum.
An active sensing is one in which the sensor emits an energy source to illuminate the target. The most common active remote sensing system is radar imagery but also include microwave radiometry, altimetry and scatterometry. Most active systems operate in the microwave portion of the electromagnetic spectrum which makes them capable of penetrating the atmosphere under virtually all conditions.
Active Sensors
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Airborne Synthetic Aperture Radar (AIRSAR)
Topographic Synthetic Aperture Radar (TOPSAR)
Airborne Light Detection and Ranging (LIDAR)
Earth Resources Satellite (ERS-1 / ERS-2)
Japanese Earth Resources Satellite (JERS)
Shuttle Imaging Radar (SIR-C / X-SAR)
RadarSAT
Passive Sensors
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Landsat Thematic Mapper (TM)
Landsat Multispectral Scanner (MSS)
Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)
Calibrated Airborne Multispectral Scanner (CAMS)
Advanced Very High Resolution Radiometer (AVHRR/HRPT)
SeaWiFS
CSR's Receiving Station
The Center for Space Research maintains an ever increasing archive of High Resolution Picture Transmission (HRPT) data from the National Oceanic and Atmospheric Administration (NOAA) polar orbiting spacecraft dating back to February 1989. The data is collected through a Seaspace Incorporated Terascan 1.2 meter antenna system.In addition to the raw HRPT data stored on over 1,300 8-mm and 4-mm tapes, subsets of the Advanced Very High Resolution Radiometer (AVHRR) data over the Gulf of Mexico and over Texas dating back to January 1991 have been extracted for easier access and are stored on approximately 750 1/2 inch 9-track reels.
CSR is also an official receiving site for the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on board the Seastar spacecraft which launched in March of 1997. Observing the Earth in 8 bands from 402nm to 885 nm, this instrument will allow improved examination of oceanic factors that affect the global environment.
On-line CSR HRPT Data Archive
On-line CSR SeaWiFS Data Archive
Last Modified: Fri June 11, 1999
CSR/TSGC Team Web