SSM/I - TMI
Boeing's Satellite Development Center (SDC) is committed to ongoing technological discovery in the field of space/science exploration. Sophisticated instruments play a key role in today's scientific and environmental space missions. The company has played important roles in meeting science objectives by: 1) providing reliable space systems, 2) integrating instruments, sensors, and subsystems provided by government agencies and industry (partners) onto a series of selected SDC spacecraft and 3) integrating SDC-built instruments and subsystems onto customers' spacecraft.
MISSION: The ability to provide timely and accurate meteorological information about ocean systems, storms, and the effects of tropical and polar weather patterns on the rest of the world is enhanced by the work of space-based microwave imagers. These instruments detect microwave energy in the form of brightness temperatures from Earth's surface and atmosphere. The temperature and atmospheric information is received by sensors and transmitted to agencies such as the Department of Defense (with primary interface with the Air Force and Navy), NASA, and National Oceanic and Atmospheric Administration (NOAA) to observe, detect, and understand meteorological phenomena.
The company's first imager, the Special Sensor Microwave/Imager, was launched in June 1987. The line was expanded to include an instrument for use on the Tropical Rainfall Measuring Mission spacecraft, launched November 27, 1997. The SDC is also under contract to build a Conical Scanning Microwave Imager/Sounder.
From predicting the ensuing "El Niño" phenomenon to saving countless lives by monitoring approaching storms, instruments such as these have become an integral tool used by meteorologists.
SSM/I: In 1979, the first Special Sensor Microwave Imager (SSM/I) contract was awarded to SDC by the U.S. Air Force. The company's challenge was to design, develop, and build a space instrument that would complement the capabilities of traditional weather sensing devices.
Special Sensor Microwave/Imager (SSM/I)
Launched on a Defense Meteorological Satellite Program (DMSP) Block 5D-2 satellite on June 19, 1987, the SSM/I is able to "see" weather images that are out of view for visible and infrared sensors on meteorological spacecraft. By detecting microwave energy emitted from Earth, SSM/I peers "into and through" the clouds. SSM/I data can be used to measure the speed of the wind at the ocean's surface; the presence, extent, and age (thickness) of ice covering the sea; the approximate amount of water in clouds; areas and intensity of precipitation; and ground moisture.
SSM/I provides data used by the military for tropical storm reconnaissance, ship routing in polar regions, agricultural weather reports, aircraft routing and refueling, and communications management.
Stowed at launch, the sensor deploys in orbit and spins at a rate of 31 revolutions per minute. With each turn, the sensor maps a swath of the Earth that is 830 miles wide. The scans overlap each other to provide a continuous image. SSM/I operates at frequencies ranging from 19 to 85 GHz.
TMI: Building on the knowledge gained from development of the SSM/I, the National Space Development Agency of Japan (NASDA) and NASA launched the SDC-built Tropical Rainfall Measuring Mission Microwave Imager, or TMI. With capabilities similar to those of SSM/I, the TMI instrument measures tropical rainfall characteristics from space by detecting microwave energy in the form of brightness temperatures from Earth's surface and atmosphere.
TMI was designed to work in conjunction with a precipitation radar built by NASDA, as well as visible and infrared sensors, and a lightning imaging sensor. The data supplied by the system provides insight into tropical storm formations and their likely paths.
TMI was launched November 27, 1997, aboard the Tropical Rainfall Measuring Mission spacecraft, built by NASA's Goddard Space Flight Center. The spacecraft operates from a circular low inclination (35¡) orbit approximately 220 miles above Earth. From this position, TMI transmits rainfall data from the tropical regions of the world bordering the equator.
The data provided by TMI gives space and weather agencies valuable insight into meteorological phenomena and their influence over unusual ocean patterns, such as the "El Niño" system. Additionally, TMI is capable of supplying information useful for tropical storm tracking, cloud and soil moisture levels, land and sea surface temperatures, wave height, and sea surface wind speeds.
Boeing Satellite Systems is the world's leading manufacturer of commercial communications satellites and a major provider of space systems, satellites, and payloads for national defense, science, and environmental applications.