SEASAT 1978

Overview

Seasat was the first Earth-orbiting satellite designed for remote sensing of the Earth's oceans and had onboard the first spaceborne synthetic aperture radar (SAR). Seasat was managed by JPL and was launched on June 28, 1978 into a nearly circular 800 km orbit with an inclination of 108 degrees. Fourteen Earth orbits were completed each day.

Five complementary experiments designed to return the maximum information from ocean surfaces were onboard:

Radar altimeter to measure spacecraft height above the ocean surface
Microwave scatterometer to measure wind speed and direction
Scanning multichannel micrwave radiometer to measure sea surface temperature
Visible and infrared radiometer to identify cloud, land and water features
Synthetic Aperture Radar (SAR) L-band, HH polarization, fixed look angle to monitor the global surface wave field and polar sea ice conditions.

The Seasat SAR operated for 105 days until October 10, 1978, when a massive short circuit in the satellite electrical system ended the mission. During Seasat operations, approximately 42 hours of data were collected.

Seasat Mission Parameters

Satellite Altitude	800 km
Radar Frequency	1.275 GHz (L-band)
Radar Wavelength	23.5 cm
System Bandwidth	19 MHz
Theoretical Resolution on the Surface	25 m (azimuth) x 25 m (range)
Number of Looks	4
Swath Width	100 km
Antenna Dimensions	10.74 m x 2.16 m
Antenna Look Angle	20 degrees from vertical
Incidence angle on the surface	23 degrees +/- 3 degrees across the swath
Polarization	Horizontal transmit, Horizontal receive (HH)
Transmitted Pulse Length	33.4 microseconds
Pulse repetition frequency (PRF)	1463-1640 Hz
Transmitted peak power	1.0 kW
Data recorder bit rate (on the ground)	110 Mbits/s (5 bits/word)

Coverage Map

Additional Seasat Information/References Can Be Found...

JPL Public Information Office - The Seasat Mission

How to Get Seasat Imaging Radar Data

All the Seasat data were acquired digitally and most of the data were optically processed to survey data products. These products are available on 70 mm film. The Seasat swath width of 100 km was processed into four 25 km wide products at JPL. Only a small percentage of the data were digitally processed; these products contain the complete 100 km wide swath of data.

The Seasat digital processor operated at JPL from 1978 to 1982. Approximately 10% of the total Seasat data set were processed to precision data before the processor was turned off. JPL currently has no capability to process additional Seasat data.

All of the data that were processed are archived at JPL. Digital data are available as byte products on 9 track 6250 bpi CCT or as 8 x 10 black and white prints, positive transparencies, or duplicate negatives. The photo products are approximately 1:500,000 scale.

For more information contact the JPL Radar Outreach Program

Selected portions of the Seasat data set were processed at the facilities listed below.

NOAA/NESDIS
Satellite Data Services Division
Princeton Executive Square, Rm. 100
5627 Allentown Road
Camp Springs, MD 20746
301-763-8402

Seasat SAR signal data collected over Europe and received at the station at Oakhanger, United Kingdom (UKO) were also processed in Europe and are available there. Inquiries can be directed to:

ESRIN - Earthnet Program Office
Via Galileo Galilei
00044 Frascati
Italy
Ph. 39-6-941-80-600
Fax 39-6-941-80-510

Approximately 70 images of 40 x 40 km Seasat scenes collected over Canada were also processed by MacDonald Dettweiler and Associates of Richmond, British Columbia, Canada. These scenes are archived at, and questions should be directed to:

Canada Centre for Remote Sensing
Satellite Acquisition Services Order Desk
588 Booth Street
Ottawa, Ontario CANADA K1A 0Y7
Tel: (613) 995-4057
Fax: (613) 992-0285
Email: orderdesk@ccrs.nrcan.gc.ca

Imaging Radar Home Page

Last updated: February 10, 1998
ellen.oleary@jpl.nasa.gov
annie.richardson@jpl.nasa.gov
bruce.chapman@jpl.nasa.gov
al.wong@jpl.nasa.gov