NWA logo Glossary of Satellite Acronyms

National Weather Association (NWA) Remote Sensing Committee

The following terms and acronyms are used in descriptions of meteorological satellite systems, instruments, data, or their display via the Internet.

ABI - Advanced Baseline Imager. Instrument on the advanced GOES-R spacecraft series (scheduled launch in 2015) that will provide the bulk of imagery for realtime monitoring of the earth within the satellite field of view. ABI will have 16 spectral bands, six of which will be visible and near-IR. Maximum resolution will be 0.5 km for the primary visible channel, 1 km for near-IR and 2 km for longwave IR bands.

AMSU - Advanced Microwave Sounder Unit. Microwave instrument onboard the NOAA-15 through NOAA-19 and European METOP spacecraft. The AMSU-A instrument consists of fifteen channels from 23.8 to 89.0 GHz with a subpoint resolution of 48 km. The AMSU-B is a five channel instrument from 89.0 to 183.0 GHz with a subpoint resolution of 16 km.

APT - Automatic Picture Transmission. Mode of transmitting images from the NOAA AVHRR. Provides low resolution (4 km) Infrared (IR) and Visible data.

ASOS - Automated Surface Observing System. A network of automatic weather observation stations operated by the U.S. National Weather Service or Dept. of Defense.

ATMS - Advanced Technology Microwave Sounder. A cross-track microwave sounder with 22 channels that combines the capabilities of the previous AMSU-A and AMSU-B instruments to provide all-weather global soundings of temperature, pressure and moisture. ATMS is currently onboard the NPP and is also planned to be on the future JPSS.

AVHRR - Advanced Very High Resolution Radiometer. Imaging instrument onboard the NOAA polar orbiting satellites. Produces infrared (IR) and visible images with a sub-point resolution of 1 km at the earth's surface.

CONUS - CONtinental United States.

CrIS - Cross-track Infrared Sounder. A Michelson interferometer that uses 1305 spectral channels to obtain vertical profiles of temperature, pressure and moisture over a 2200 km wide swath at a resolution of about 14 km. CrIS is onboard the NPP and is also planned to be on the future JPSS.

DMSP - Defense Meteorological Satellite Program. A series of low altitude (550km), polar orbiting satellites operated by the Department of Defense. Provides high resolution (0.5 km) visible and IR, plus passive microwave imagery (25-40 km). Data is made available via the Shared Processing Network and archived at the National Geophysical Data Center, Boulder, CO.

EMWIN - Emergency Managers Weather Information Network. A direct broadcast service that provides users with weather forecasts, warnings, graphics, and other information directly from the National Weather Service (NWS) in near real time.

ENVISAT - Polar orbiting spacecraft operated by the European Space Agency possessing several instruments used to monitor the earth's environment. Parameters measured include ozone concentration, aerosols, surface stress for earthquake potential, sea level heights, and fires.

EUMETSAT - European Organisation for the Exploitation of Meteorological Satellites. Delivers weather and climate-related satellite data, images and products 24 hours a day, 365 days a year to meteorological agencies of member states.

EXIS - Extreme ultraviolet and X-ray Irradiance Sensors. A suite of instruments scheduled for launch on GOES-R in 2015 that will detect solar "soft" X-rays and extreme UV irradiance in the 5-127 nm range. Will help to warn of serious impacts on terrestrial communication, navigation, power grids, etc

GIF - Graphical Information Format. Common image format used on the Internet, developed by Compuserve. Main advantage of using the GIF format is that it occupies relatively little file space.

GLM - Geostationary Lightning Mapper. Will obtain realtime observations of total lightning (in-cloud and cloud-to-ground) from space, beginning with the GOES-R series, to be launched in 2015. Detection rate is expected to be 70-90% day and night. GLM uses a single spectral band at 777nm wavelength. Spatial resolution will be 10 km at satellite sub-point.

GMS - (Himiwari) geostationary satellite operated by the Japanese Meteorological Agency. Views the western Pacific Ocean, eastern Asia, the Indian Ocean, and Australia and New Zealand. Provides images in visible and three IR channels at resolutions of 2.5 km and 5 km, respectively.

GOMS - Geostationary Operational Meteorological Satellite. The first GOMS was launched by the Russian government on October 31, 1994 and has not provided images since 1998. GOMS is located above the Indian Ocean on the Equator at 76 degrees East. To date, no new GOMS spacecraft have been placed in orbit.

GOES - Geostationary Operational Environmental Satellite. A U.S. satellites operated by NOAA. Positioned in a nearly stationary orbit over the Equator at an altitude of about 22,500 miles. GOES-12 is currently the operational east spacecraft at 75 degrees West, while GOES-11 is the west spacecraft located at 135 degrees West. GOES-10 is situated at 60W and is providing images of South America.

GPS - Global Positioning System. Constellation of polar-orbiting satellites that provides accurate earth position data for commerce. Refraction (occultation) of the GPS radio signals caused by atmospheric density and moisture can be used to derive Total Precipitable Water for weather forecast applications.

HRPT - High Resolution Picture Transmission. High resolution imaging mode from the AVHRR on the NOAA satellites. Data is produced in five channels with a resolution of 1km at the satellite subpoint (nadir).

INDOEX - Indian Ocean Experiment. Images (Visible, IR, Water Vapor) obtained from a METEOSAT spacecraft centered over the Indian Ocean.

INSAT - Indian Satellite operated by Indian Space Agency. This geostationary satellite is located at 74 degrees East, providing three-hourly visible and infrared coverage of Asia, east Africa, and the Indian Ocean region.

IR - Infrared. Type of satellite image that shows earth-emitted radiance in various wavelengths, usually near 4, 6-7, and 10-12 micrometers. Advantage of IR is that it can be used to monitor weather and oceanographic conditions 24 hours a day.

JPEG - Joint Photographic Expert Group. Image format that uses data compression techniques to reduce the size of the image file. Supports 8 or 24 bits-per-pixel.

JPSS - Joint Polar Satellite System. Program that will merge the legacy NOAA POES, NASA and DMSP polar satellite capabilities, with initial launch planned later this decade.

LAC - Local Area Coverage. High resolution (1km) image data from AVHRR that is obtained over remote areas, saved via onboard data recorder, then later transmitted to a ground station.

LI - Lifted Index. Difference in temperature between an air parcel lifted adiabatically from the surface to 500 mb (about 18,000ft) and the environmental temperature at that level. A product that can be derived from GOES imager or sounder data, as well as radiosonde or numerical model data.

METEOSAT - Series of geostationary satellites operated by the European Space Agency. Meteosat Second Generation (MSG) now provides imagery in visible, plus eleven IR bands, including longwave IR (10.5 micrometer) and water vapor (6.5 micrometer) channels at 2.5 km resolution. Centered near Greenwich meridian (0 deg Longitude). METEOSAT is also providing images of the Indian subcontinent at 63 deg East (referred to as INDOEX).

METOP - Series of low earth orbit spacecraft developed by EUMETSAT that will provide observations using heritage instruments from the NOAA series such as AVHRR. The first METOP (-A) was launched in 2006.

MODIS - Moderate resolution Infrared Spectroradiometer. Instrument on NASA Aqua and Terra spacecraft that provide Visible and IR data from 36 channels at sub-point resolutions from 250m to 1 km.

MPEG - Moving Picture Experts Group. Image format used to display animated sequences (movies). Requires considerable system memory to run, depending on movie size.

MTSAT - Multi-purpose Transport SATellite (Japan). Replacement for GMS at 140E since 2005. Also supports transport navigation within Japan.

NCDC - National Climatic Data Center, Asheville, NC. Archive center for all meteorological data, including satellite imagery. Operated by NOAA/NESDIS.

NESDIS - National Environmental Satellite Data, Information Service. Government agency that operates the U.S. civilian weather satellites and provides the data to users. Also operates the environmental data centers such as NGDC and the National Climatic Data Center (NCDC) in Asheville, NC.

NGDC - National Geophysical Data Center, Boulder, Colorado. Archives most imagery from DMSP satellites (OLS, SSM/I microwave data). Also houses the Snow and Ice Data Center.

NOAA - National Oceanographic and AtmosphericAdministration. Refers to a series of low earth orbit satellites at an altitude of 530 miles, operated by the U.S. government agency of the same name. Orbits are sun-synchronous such that they pass over a given location at about the same local time each day.

NPOESS - National Polar Orbiting Environmental Satellite System. Merger of U.S. civilian and military polar orbiting satellite systems to replace the NOAA and DMSP spacecraft beginning with the launch of NPP in late 2011. Program is now known as JPSS.

NPP - NPOESS Preparatory Project. A prototype NPOESS system launched in late 2011. Has several experimental instruments (VIIRS, CrIS, ATMS, CERES, OMPS) that are expected to be the backbone of the future JPSS.

OLS - Operational Line Scanner. The imager that produces high resolution (0.5 to 2.7 km) visible and infrared imagery from DMSP satellites.

OMI - Ozone Monitoring Instrument. An instrument on board the NASA Aura spacecraft, OMI obtains measurements of solar backscatter in 740 visible and UV spectral bands to derive concentrations of ozone and other trace gases such as NO2, SO2, etc. Normal resolution is 13 x 24 km, maximum resolution is 13km x 13km to map pollution on an urban scale. Can also obtain vertical ozone profiles. OMI is a joint effort between NASA and the Netherlands's Agency for Aerospace Programs (NIVR), in collaboration with the Finnish Meteorological Institute (FMI).

OMPS - Ozone Mapper Profiler Suite. OMPS measures and maps the global distribution of the total atmospheric ozone column on a daily basis, and the vertical distribution of ozone from about 15 km to 60 km somewhat less frequently. OMPS is onboard the NPP and is also planned to be on the future JPSS.

PW - Precipitable Water. Total amount of water vapor within an atmospheric column (expressed in mm) available for precipitation. One of the products derived from the GOES/POES imager or sounder.

RAMSDIS - Regional and Mesoscale Meteorological Satellite Data and Information System. A PC-based display system developed at Colorado State University in the early 1990's to provide frequent animation of GOES imagery and derived products. Most products are now available on the CIRA Web site.

SAA - Satellite Active Archive. Digital archive of satellite imagery from the NOAA polar orbiting series. User can browse through sample images and order digital data online. Now referred to as the Comprehensive Large Array Stewardship System (CLASS).

SARSAT - Search and Rescue Satellite Aided Tracking. SARSAT detects and locates mariners, aviators, and other recreational users in distress almost anywhere in the world at anytime and in almost any condition. This system uses a network of satellites to quickly detect and locate distress signals from emergency beacons onboard aircraft, vessels, and from handheld personal locator beacons called PLBs. SARSAT web site

SeaWIFS - Sea-viewing Wide Field-of-view Sensor. The instrument has eight channels in the visible and near-IR portion of the spectrum (0.4um to 0.9um) at a subpoint resolution of 1.1 km. SeaWIFS data is used to observe ocean color features as well as other phenomena at a frequency of one overpass per day.

SEISS - Space Environment In-Situ Suite. An array of sensors scheduled for launch on GOES-R in 2015 that will monitor the proton, electron, and heavy ion fluxes at geosynchronous orbit. SEISS data is critical for assessing the radiation hazard to astronauts and satellites, and to warn of high flux events, mitigating any damage to radio communication.

SEVIRI - Spinning Enhanced Visible and Infrared Imager. Instrument on the METEOSAT Second Generation (MSG) spacecraft featuring 12 spectral bands. The four Vis and Near IR bands and the eight IR bands have resolutions of 1 km and 3 km, respectively. Available in High (15 min) and Low Rate (30 min) transmissions.

SSM/I - Special Sensor Microwave/Imager. Passive microwave instrument onboard the U.S. Dept. of Defense meteorological satellites (DMSP). Obtains data in seven channels (four wavelengths, three with vertical/horizontal polarization) at resolutions of 25 km (85 Ghz only) and 40 km.

SST - Sea Surface Temperature. Temperature slightly below the ocean surface as measured by ocean buoys and ships or on the ocean surface as measured by satellite infrared measurements.

SUVI - Solar UltraViolet Imager. A telescope onboard the GOES-R spacecraft (2015 scheduled launch) that observes the Sun in the extreme ultraviolet (EUV) wavelength range in six spectral bands. It provides full-disk solar images with approximately 5 arcsec spatial resolution at 10 second imaging intervals. SUVI will detect solar flares and coronal mass ejections that could result in disruption of utilities, communications, navigation, and damage to spacecraft.

TIFF - Tagged Image File Format. A compressed file format that is often used for high quality images.

TPW - Total Precipitable Water. The total amount of moisture available for precipitation in an atmospheric column, usually expressed in mm.

Vegetation Index (VI) - Determined using visible and near-IR channels on AVHRR. Denotes relative chlorophyll content of vegetation during daylight conditions, and is thus used to monitor drought conditions.

VIIRS - Visible/Infrared Imager Radiometer Suite. The primary imager on the NPP (launched late 2011) and future JPSS systems, VIIRS will provide high resolution (0.4-0.8 km) data in 22 spectral bands with global coverage. Includes a day/night visible channel such as that on DMSP.

Vis - Visible satellite imagery that shows reflected sunlight in the ultraviolet portion of the spectrum (0.5 to 1.0 micrometers).

WEFAX - Weather Facsimile. A type of low resolution imagery broadcast directly from a satellite to a user on the ground with proper receiving equipment.

WV - Water Vapor. Imagery available from GOES, MTSAT and METEOSAT that shows middle and upper tropospheric moisture and other significant features.

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Maintained by Gary Ellrod
Last Update: 14 January 2012