This section contains information on terms, phrases and abbreviations used by the NOAA CoastWatch. It's purpose is to aid the general public in better understanding CoastWatch data products.
ACSPO Clear Sky Mask
Advanced Clear Sky Processing for Oceans (Processing system for NOAA Sea Surface Temperature products)
Tiny droplets or particles in the atmosphere
Series of calculations following a set of rules
Instrument used to measure the altitude of an object above sea level.
Advanced Microwave Sounding Unit
Difference or variability from a defined reference point
Aerosol Optical Depth
Aerosol Optical Thickness
Application program interface
The point in a satellite's orbit furthest away from Earth.
Proprietary global information system mapping software
Advanced SCATterometer - a real aperture radar instrument aboard EUMETSAT’s Metop series of three polar orbiting meteorological satellites
American Standard Code for Information Interchange, a computer format
Advanced TIROS Operational Vertical Sounder (suite of sounding instruments including AMSU-A, AMSU-B and HIRS/3).
Advanced Very High Resolution Radiometer, on NOAA polar orbiting satellites for measuring sea surface temperature and other parameters
An arc of the horizon measured between a fixed point (as true north) and the vertical circle passing through the center of an object.
The portion of power scattered back in the incident direction.
Range of wavelengths
A hypothetic body that completely absorbs all wavelengths of thermal radiation incident on it. Such bodies do not reflect light, and therefore appear black if their temperatures are low enough so as not to be self-luminous.
Indicates a mix of satellite and in situ observations
Bi-directional Reflection Distribution Function
Binary Universal Form for the Representation of meteorological data.
Structure anchored at the bottom, floating (moves, but chained) at the surface, sometimes used as a platform from which to deploy oceanographic instruments.
The portion of the electromagnetic spectrum ranging from 4-8 GHz.
Calibration and Validation
CoastWatch Data Analysis Tool
Committee on Earth Observation Satellites (an international body)
Clouds and Earth's Radiant Energy System
The pigment in plants and phytoplankton that is responsible for photosynthesis
Comprehensive Large Array-data Stewardship System, NOAA’s data archive
Monitoring changes in climate trends in satellite data.
Coordinated Universal Time (UTC)
By international agreement, the local time at the prime meridian, which passes through Greenwich, England (previously know as GMT). The time used by EUMETSAT on data/products and satellite operational events.
Large, long term European Commission program for environmental Earth observations, including observations from remote sensing satellites and in situ observations
A plant, animal and mineral assemblage living together which functions as a colonial "organism"
Data occurring over a 10-year period.
A day night cycle
Special sensor microwave/imager (SSM/I) on board the United States Air Force Defense Meteorological Satellite Program (DMSP)
Digital object identifier
The study of the relationships among organisms and environment
Unit of interacting living resources and environment
The study of effects of harmful substances on organisms and ecosystems
Swirl of water counter to the predominant current
Based on observations rather than theory
European Space Agency
Company that make ArcGIS software
EUMETSAT's Data Distribution System, which broadcasts data to users.
European Organisation for the Exploitation of Meteorological Satellites
Food and Agriculture Organization of the United Nations; Publishes an annual report on the state of world fisheries and aquaculture
Frequently Asked Questions
Prediction or estimation; at NOAA, a forecast indicates that human judgment is involved in the analytical process whereas a prediction could be simply the output of a computer model, for example
A computer transfer protocol
Global Area Coverage
General Circulation Model, a numerical model that represents physical processes in the ocean and atmosphere (or other fluid environments)
Graphic Database System; a computer file format
Indicates a blend of data from geostationary orbiting and polar orbiting satellites
A geo-synchronous orbit such that the satellite appears to be stationary above the primary (e.g., Earth)
Global Forecast System; a weather forecast model at NOAA
Group for High Resolution Sea Surface Temperature; international professional group which sets standards for SST
A packet of data of a standardized size/coverage area (for example, a set number of scans rows (which also relates to time) along a set swath width) from a satellite sensor. For example, A VIIRS SNPP granule is 48 scans (approximately 85 seconds, which is approximately 570 km) x approximately 3,040 km
Harmful Algal Bloom; a fast growing accumulation of toxic algae
Hierarchical Data Format
High Resolution Infra Red Radiation Sounder
The scientific study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water on or below the land surface.
Instantaneous Field Of View
In plane maneuver
Operation implementing, by activation of thrusters, a change of the orbital velocity of a satellite in the in-flight direction (and consequently a change of the semi-major-axis of the orbit). These maneuvers are used to compensate for the orbital perturbations caused by the drag (for Low Earth Orbit satellites, leading to orbital decay) or the gravity field asymmetry (for geostationary satellites, leading to longitude drift); as the eccentricity of the orbit is also modified at the same time, these maneuver can be used to compensate for the orbital perturbations caused by the solar radiation pressure (leading to a change of the orbital eccentricity).
Angle between orbital plane of satellite and equatorial plane of reference (e.g., Earth)
Infrared radiation (IR) and Infrasatellite imagery
IR is the region of the electromagnetic spectrum adjacent to that of visible light, but with longer wavelengths (0.65-10 micrometers, typically). IR satellite imagery senses surface and cloud top temperatures by measuring the wavelength of electromagnetic radiation emitted from these objects.
Quality monitoring system for in situ sea surface temperature observations
National Remote Sensing Centre Indian Space Research Organisation
International, multi-agency satellite missions for ocean altimetry. Named for Greek mythological Jason and the Argonauts
Jet Propulsion Laboratory (NASA)
Joint Polar Satellite System
Joint Research Centre (European Commission)
Diffuse attenuation coefficient at the 490 nm wavelength
The portion of the electromagnetic spectrum ranging from 12-18 GHz.
L0, L1, L2, L2P, L3, L4
Levels of data processing involved in making satellite "products". These are not fixed definitions but here is an idea of what they might indicate: beginning from raw computer bits and bytes (L0), to calibrated instrument measurement (L1), to environmentally relevant geophysical parameters of interest (L2), to parameters from a single sensor that have been spatially or temporally binned or mapped or gridded for example (L3) and products derived from a combination of multiple sensors or a combination of satellite and in situ observations. GHRSST uses additional qualifiers to indicate other processing level details. L2p, L2u, L3p and others have specific meanings for GHRSST sea surface temperature. See the GHRSST product site (https://www.ghrsst.org/ghrsst-data-services/products/) for details.
The amount of time delay between satellite observation and when a satellite product is available to be used for an application
Lower Earth Orbit
Look up tables
Multi-channel sea surface temperature
cylindrical map projection
line of longitude
MEdium Resolution Imaging Spectrometer (ESA's Envisat platform)
explanatory information about a given data set
Series of polar orbiting meteorological operational satellites (Metop-A, Metop-B, Metop-C; developed by ESA; operated by EUMETSAT)
electromagnetic energy at wavelengths ranging from one meter to one millimeter
Microwave Imaging Radiometer using Aperture Synthesis aboard SMOS satellite (soil moisture and ocean salinity)
Marine Optical BuoY
Moderate Resolution Imaging Spectroradiometer
MODerate resolution Imaging Spectroradiometer aboard the Aqua satellite (NASA)
When target scene is directly below the satellite (lowest viewing angle)
National Aeronautics and Space Administration
National Centers for Environmental Information (NOAA/NESDIS)
National Center for Environmental Predictions (NOAA/NWS)
In the satellite remote sensing context, refers to very low data latencies (e.g., data product is available as soon as possible after the remote observation)
National Environmental Satellite, Data, and Information Service (NOAA)
Network Common Data Form
Non-Linear Sea Surface Temperature
normalized water-leaving radiance
National Marine Fisheries Service (NOAA)
National Oceanic and Atmospheric Administration (US Department of Commerce)
Point of connection; information about the NOAA CoastWatch Nodes can be found at here
National Ocean Service (NOAA)
National Polar-orbiting Operational Environmental Satellite System (NOAA)
National Polar-orbiting Operational Environmental Satellite System Preparatory Project (satellite renamed to Suomi-NPP)
National Research Council
Near Real Time
Office of Oceanic and Atmospheric Research (NOAA)
Ocean and Land Color Instrument (aboard Sentinel-3; Copernicus Program)
The path of a body in space, generally under the influence of gravity.
Office of Satellite and Product Operations
Operation implementing, by activation of thrusters, a change of the orbital velocity of a satellite in the direction normal to the orbital plane (and consequently a change of the inclination of the orbit). These maneuvers are used to compensate for the orbital perturbations caused by the sun and moon gravity (leading to a change of the orbital inclination). For LEO satellites, as the rate of drift of the mean local solar time of the orbit is linked with the orbital inclination, these maneuver can also be used to implement a change of that rate.
The carrying capacity of a spacecraft, including cargo, scientific instruments or fuel.
The point in the orbit of the moon or a satellite at which it is nearest to the earth
Datum unit in a grid
Identification of an individual satellite which may carry several instruments or sensors
NOAA’s Polar Operational Environmental Satellites
A NOAA data portal specializing in ocean and ice remote sensing satellite data and images in mapped projections useful to high latitude regions (Arctic and Antarctic): see: polarwatch.noaa.gov
Radar altimeter onboard Jason-3
Using radio waves to detect (and characterize) a target object
Radar satellite mission operated in a partnership between a commercial company and the Canadian Space Agency
Measure of electromagnetic energy (e.g., light or heat energy)
Electromagnetic energy in the form of waves
Instrument that measures radiance
Abbreviation for systematic reanalysis or reprocessing of satellite data products, in this context
Data in rows and columns
Red Green Blue
Root Mean Square
Synthetic Aperture Radar, a remote sensing technique measures surface variability ("roughness")
Radar systems that infer wind speed by measuring the backscattering cross section. Scatterometers can measure the received power of surface backscattering reflected from the surface of objects.
The radius of an orbit at its widest point
The "business" part of an instrument that makes the observation
The long term multi-satellite mission for remotely sensed Earth observations in the European Copernicus program. Satellites are named by number and letter (e.g., Sentinel-1B, which primarily makes SAR observations and Sentinel-3A, which has instruments for ocean color, sea surface temperature and ocean altimetry)
Spinning Enhanced Visible and Infrared Imager onboard ESA’s Meteosat Second Generation (MSG) satellite mission
Sea and Land Surface Temperature Radiometer onboard Sentinel-3 of the EU Copernicus mission
Soil Moisture and Ocean Salinity, an ESA satellite mission
Water contained in the upper part of the soil mantle.
Instrument that makes profile or "vertical" observations (e.g., of the atmosphere)
Instruments that acquire multispectral measurements from which vertical profiles of atmospheric temperature and humidity can be derived to produce particular measurements of depth of water below an instrument (at the surface or at some moored depth), which is computed from the travel time of the acoustic pulse emitted by this sounder.
Observation in profile (e.g., of a column of atmosphere)
Instrument that make observations across a range of wavelengths
spectrum, spectra, spectral
Spectrum is a set of observations across a range of wavelengths, spectra is plural of spectrum, spectral is adjective form
The method of stabilizing a satellite by means of spin.
NOAA/STAR Sea Surface Temperature Quality Monitor
Synthetic Aperture Radar Altimeter onboard Sentinel-3 of the EU Copernicus mission
Single Senor Error Statistic used by GHRSST
Special Sensor Microwave/Imager onboard the DMSP
Sea Surface Salinity
Sea Surface Temperature
Center for Satellite Applications and Research
Layer of atmosphere above the troposphere. The troposphere is closest to Earth
Extra rays of light hitting SEVIRI's optical path and degrading images.
In a sun-synchronous orbit, though, the satellite passes over the same part of the Earth at roughly the same local time each day.
The path width of remote sensing instrument observation
Thematic Real-time Environmental Distributed Data Services
Satellite platform type. Involves the use of three gyroscopes - one for each axis - to keep satellites correctly oriented in space.
Tagged Image File Format
Television Infrared Observation Satellite (NASA), first experimental satellite for Earth/weather observations
Top of atmosphere
Observation from satellite instrument at the point of the instrument, no adjustments have been made to remove signals contributed by constituents not of primary interest
The shape of the ocean and land. It is used in the context of Jason-2 service.
Layer of atmosphere closest to Earth
Electromagnetic energy at ~10 nm to 400 nm wavelengths (shorter than the visible spectrum which is about 400 nm to 700 nm)
Dynamic property of ocean physics whereby relatively warm surface waters are forced away allowing deeper ocean water (usually relatively colder and more nutrient-rich) to fill in or replace the disturbed surface water
US Environmental Protection Agency
US Geological Survey
Universal Time Constant (equivalent to Greenwich Mean Time)
In this context, refers to comparing satellite observations against another earth observation (e.g., in situ or another satellite) to evaluate the performance of a sensor/instrument
Visible Infrared Imaging Radiometer Suite
Electromagnetic energy at visible (to human eyes) wavelengths (about 400 nm to 700 nm)
World Geodetic System 1984, the reference coordinate system for the Global Positioning System (GPS)
World Ocean Circulation Experiment, long term program/dataset of physical oceanographic measurements