Launched by NASA in 1978, the Seasat satellite’s primary mission was to observe oceans using NASA’s first synthetic aperture radar (SAR) sensor. SAR bounces a microwave radar signal off the surface of Earth to detect physical properties. Unlike optical photo technology, SAR can see through darkness, clouds, and rain.
Through the use of SAR, the Seasat satellite collected an enormous amount of data for its time. This data has been processed by the Alaska Satellite Facility, a NASA Distributed Active Archive Center (DAAC), into digital imagery that allows scientists to measure features of the planet’s surface over time.
| Parameter | Value |
|---|---|
| Temporal Coverage | June – October 1978 |
| Spatial Coverage | Oceans, sea ice |
| Center Frequency | 1.275 GHz (L-Band) |
| Polarization | Horizontal transmit, horizontal receive (HH) |
| Spatial Resolution | 25 m azimuth x 25 m range |
| Swath Width | 100 km |
| Off-Nadir Angle | 108° |
| File Format | Geotiff or HDF5 |
| Date Published | 2013 |
| System Bandwidth | 19 MHz (linear FM) |
| Satellite Altitude | 800 km |
| Pulse duration | 33.4 us |
| Antenna Dimensions | 10.74 m x 2.16 m |
| Ground incidence angle | 23°± 3° cross track |
| No. of looks | 4 |
| Data recorder bit rate (on the ground) | 110 Mbits/s (5 bits/word) |
| Radar Wavelength | 23.5 cm |
| Pulse Repetition Frequency (PRF) | 1463-1640 Hz |
| Antenna Look Angle | 20° from vertical (fixed) |
| Antenna type | 1024-element passive micro-strip based arrays antenna, linearly polarized |
| Transmitted peak power | 1 kW |
Seasat set a Landmark in Remote-Sensing History in 1978. On June 27 GMT, 1978, NASA undertook a momentous task: launching the Seasat satellite in order to demonstrate the feasibility of orbital remote sensing for ocean observation. On board was the first NASA synthetic aperture radar sensor ever deployed.
This mission supplied the decades-old data that the Alaska Satellite Facility, a NASA Distributed Active Archive Center (DAAC), has processed into a treasure trove of digital images. The new imagery enables scientists to travel back in time for research on oceans, sea ice, volcanoes, forest land cover, glaciers, and more. Before now, only a small percentage of Seasat data was processed digitally.
Although Seasat suffered a catastrophic power failure on October 10, 1978, in 106 days the satellite collected more synthetic aperture radar information about the ocean surface — its primary mission — than had been acquired in the previous 100 years of shipboard research.
Synthetic aperture radar, also known as SAR, bounces a microwave radar signal off the surface of Earth to detect physical properties. Unlike optical photo technology, SAR can see through darkness, clouds, and rain.
The scientific value of Seasat’s SAR is extensive, providing unique and unexpected views of the dynamic ocean surface and sea ice cover, as well as the vegetated, exposed, populated, and cold regions of Earth’s surface. ASF’s new suite of Seasat products are likely to be valuable in a range of scientific disciplines, particularly for studies that measure features of the planet’s surface over time. Examples include the following:
In addition to SAR, Seasat satellite instruments included a radar altimeter, a scatterometer, a scanning multichannel microwave radiometer, and a visible/infrared radiometer.
Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use Policy.
Through the use of SAR, the Seasat satellite collected an enormous amount of data for its time. This data has been processed by the Alaska Satellite Facility, a NASA Distributed Active Archive Center (DAAC), into digital imagery that allows scientists to measure features of the planet’s surface over time
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