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

ACSM
ACSPO Clear Sky Mask
ACSPO
Advanced Clear Sky Processing for Oceans (Processing system for NOAA Sea Surface Temperature products)
aerosol
Tiny droplets or particles in the atmosphere
algorithm
Series of calculations following a set of rules
Altimeter
Instrument used to measure the altitude of an object above sea level.
AMSU
Advanced Microwave Sounding Unit
anomaly
Difference or variability from a defined reference point
AOD
Aerosol Optical Depth
AOT
Aerosol Optical Thickness
API
Application program interface
apogee
The point in a satellite's orbit furthest away from Earth.
ArcGIS
Proprietary global information system mapping software
ASCAT
Advanced SCATterometer - a real aperture radar instrument aboard EUMETSAT’s Metop series of three polar orbiting meteorological satellites
ASCII
American Standard Code for Information Interchange, a computer format
ATOVS
Advanced TIROS Operational Vertical Sounder (suite of sounding instruments including AMSU-A, AMSU-B and HIRS/3).
AVHRR
Advanced Very High Resolution Radiometer, on NOAA polar orbiting satellites for measuring sea surface temperature and other parameters
azimuth
An arc of the horizon measured between a fixed point (as true north) and the vertical circle passing through the center of an object.
backscatter
The portion of power scattered back in the incident direction.
band
Range of wavelengths
blackbody
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.
blended
Indicates a mix of satellite and in situ observations
BRDF
Bi-directional Reflection Distribution Function
BUFR
Binary Universal Form for the Representation of meteorological data.
buoy
Structure anchored at the bottom, floating (moves, but chained) at the surface, sometimes used as a platform from which to deploy oceanographic instruments.
C-band
The portion of the electromagnetic spectrum ranging from 4-8 GHz.
Cal/Val
Calibration and Validation
CDAT
CoastWatch Data Analysis Tool
CEOS
Committee on Earth Observation Satellites (an international body)
CERES
Clouds and Earth's Radiant Energy System
chlorophyll-a
The pigment in plants and phytoplankton that is responsible for photosynthesis
CLASS
Comprehensive Large Array-data Stewardship System, NOAA’s data archive
Climate Monitoring
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.
Copernicus
Large, long term European Commission program for environmental Earth observations, including observations from remote sensing satellites and in situ observations
coral
A plant, animal and mineral assemblage living together which functions as a colonial "organism"
decadal
Data occurring over a 10-year period.
diurnal
A day night cycle
DMSP/SSMI
Special sensor microwave/imager (SSM/I) on board the United States Air Force Defense Meteorological Satellite Program (DMSP)
DOI
Digital object identifier
ecology
The study of the relationships among organisms and environment
ecosystem
Unit of interacting living resources and environment
ecotoxicology
The study of effects of harmful substances on organisms and ecosystems
eddy, eddies
Swirl of water counter to the predominant current
empirical
Based on observations rather than theory
ESA
European Space Agency
ESRI
Company that make ArcGIS software
EUMETCast
EUMETSAT's Data Distribution System, which broadcasts data to users.
EUMETSAT
European Organisation for the Exploitation of Meteorological Satellites
FAO
Food and Agriculture Organization of the United Nations; Publishes an annual report on the state of world fisheries and aquaculture
FAQ
Frequently Asked Questions
flux
Continuous exchange
forecast
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
FTP
A computer transfer protocol
GAC
Global Area Coverage
GCM
General Circulation Model, a numerical model that represents physical processes in the ocean and atmosphere (or other fluid environments)
GDS2
Graphic Database System; a computer file format
GEO-POLAR
Indicates a blend of data from geostationary orbiting and polar orbiting satellites
geostationary orbit
A geo-synchronous orbit such that the satellite appears to be stationary above the primary (e.g., Earth)
GFS
Global Forecast System; a weather forecast model at NOAA
GHRSST
Group for High Resolution Sea Surface Temperature; international professional group which sets standards for SST
granule
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
HAB
Harmful Algal Bloom; a fast growing accumulation of toxic algae
HDF
Hierarchical Data Format
HIRS/3
High Resolution Infra Red Radiation Sounder
hydrology
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.
IFOV
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).
inclination
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.
iQuam
Quality monitoring system for in situ sea surface temperature observations
IR
Infrared
ISRO
National Remote Sensing Centre Indian Space Research Organisation
Jason-2, Jason-3
International, multi-agency satellite missions for ocean altimetry. Named for Greek mythological Jason and the Argonauts
JPL
Jet Propulsion Laboratory (NASA)
JPSS
Joint Polar Satellite System
JRC
Joint Research Centre (European Commission)
Kd490
Diffuse attenuation coefficient at the 490 nm wavelength
Ku-Band
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.
latency
The amount of time delay between satellite observation and when a satellite product is available to be used for an application
LEO
Lower Earth Orbit
LUT
Look up tables
MCSST
Multi-channel sea surface temperature
mercator
cylindrical map projection
meridian
line of longitude
MERIS
MEdium Resolution Imaging Spectrometer (ESA's Envisat platform)
metadata
explanatory information about a given data set
METOP
Series of polar orbiting meteorological operational satellites (Metop-A, Metop-B, Metop-C; developed by ESA; operated by EUMETSAT)
microwave
electromagnetic energy at wavelengths ranging from one meter to one millimeter
MIRAS
Microwave Imaging Radiometer using Aperture Synthesis aboard SMOS satellite (soil moisture and ocean salinity)
MOBY
Marine Optical BuoY
MODIS
Moderate Resolution Imaging Spectroradiometer
MODIS/Aqua
MODerate resolution Imaging Spectroradiometer aboard the Aqua satellite (NASA)
nadir
When target scene is directly below the satellite (lowest viewing angle)
NASA
National Aeronautics and Space Administration
NCEI
National Centers for Environmental Information (NOAA/NESDIS)
NCEP
National Center for Environmental Predictions (NOAA/NWS)
near real-time
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)
NESDIS
National Environmental Satellite, Data, and Information Service (NOAA)
NetCDF
Network Common Data Form
NIR
Near Infrared
NLSST
Non-Linear Sea Surface Temperature
nLw
normalized water-leaving radiance
NMFS
National Marine Fisheries Service (NOAA)
NOAA
National Oceanic and Atmospheric Administration (US Department of Commerce)
node
Point of connection; information about the NOAA CoastWatch Nodes can be found at here
NOS
National Ocean Service (NOAA)
NPOESS
National Polar-orbiting Operational Environmental Satellite System (NOAA)
NPP
National Polar-orbiting Operational Environmental Satellite System Preparatory Project (satellite renamed to Suomi-NPP)
NRC
National Research Council
NRT
Near Real Time
OAR
Office of Oceanic and Atmospheric Research (NOAA)
OC
Ocean Color
OLCI
Ocean and Land Color Instrument (aboard Sentinel-3; Copernicus Program)
orbit
The path of a body in space, generally under the influence of gravity.
OSPO
Office of Satellite and Product Operations
out-of-plane maneuver
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.
payload
The carrying capacity of a spacecraft, including cargo, scientific instruments or fuel.
perigee
The point in the orbit of the moon or a satellite at which it is nearest to the earth
pixel
Datum unit in a grid
platform
Identification of an individual satellite which may carry several instruments or sensors
POES
NOAA’s Polar Operational Environmental Satellites
PolarWatch
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
Poseidon-3B
Radar altimeter onboard Jason-3
QA
Quality Assurance
QC
Quality Control
radar
Using radio waves to detect (and characterize) a target object
RADARSAT-2
Radar satellite mission operated in a partnership between a commercial company and the Canadian Space Agency
radiance
Measure of electromagnetic energy (e.g., light or heat energy)
radiation
Electromagnetic energy in the form of waves
radiometer
Instrument that measures radiance
RAN
Abbreviation for systematic reanalysis or reprocessing of satellite data products, in this context
raster
Data in rows and columns
RGB
Red Green Blue
RMS
Root Mean Square
S-NPP
Suomi-NPP
SAR
Synthetic Aperture Radar, a remote sensing technique measures surface variability ("roughness")
Scatterometer
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.
semi-major-axis
The radius of an orbit at its widest point
Sensor
The "business" part of an instrument that makes the observation
Sentinel
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)
SEVIRI
Spinning Enhanced Visible and Infrared Imager onboard ESA’s Meteosat Second Generation (MSG) satellite mission
SLSTR
Sea and Land Surface Temperature Radiometer onboard Sentinel-3 of the EU Copernicus mission
SMOS
Soil Moisture and Ocean Salinity, an ESA satellite mission
Soil Moisture
Water contained in the upper part of the soil mantle.
sounder
Instrument that makes profile or "vertical" observations (e.g., of the atmosphere)
sounders
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.
sounding
Observation in profile (e.g., of a column of atmosphere)
spectrometer
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
Spin-stabilized
The method of stabilizing a satellite by means of spin.
SQUAM
NOAA/STAR Sea Surface Temperature Quality Monitor
SRAL
Synthetic Aperture Radar Altimeter onboard Sentinel-3 of the EU Copernicus mission
SSES
Single Sensor Error Statistic used by GHRSST
SSM/I
Special Sensor Microwave/Imager onboard the DMSP
SSS
Sea Surface Salinity
SST
Sea Surface Temperature
STAR
Center for Satellite Applications and Research
stratosphere
Layer of atmosphere above the troposphere. The troposphere is closest to Earth
straylight
Extra rays of light hitting SEVIRI's optical path and degrading images.
sun-synchronous
In a sun-synchronous orbit, though, the satellite passes over the same part of the Earth at roughly the same local time each day.
swath
The path width of remote sensing instrument observation
telemetry
Remote observation
THREDDS
Thematic Real-time Environmental Distributed Data Services
three-axis stabilized
Satellite platform type. Involves the use of three gyroscopes - one for each axis - to keep satellites correctly oriented in space.
TIFF
Tagged Image File Format
TIROS
Television Infrared Observation Satellite (NASA), first experimental satellite for Earth/weather observations
TOA
Top of atmosphere
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
topography
The shape of the ocean and land. It is used in the context of Jason-2 service.
troposphere
Layer of atmosphere closest to Earth
ultraviolet
Electromagnetic energy at ~10 nm to 400 nm wavelengths (shorter than the visible spectrum which is about 400 nm to 700 nm)
upwelling
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
USEPA
US Environmental Protection Agency
USGS
US Geological Survey
UTC
Universal Time Constant (equivalent to Greenwich Mean Time)
UV
Ultraviolet
validation
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
VIIRS
Visible Infrared Imaging Radiometer Suite
VIS
Electromagnetic energy at visible (to human eyes) wavelengths (about 400 nm to 700 nm)
VIS/IR
Visible/Infrared
WGS84
World Geodetic System 1984, the reference coordinate system for the Global Positioning System (GPS)
WOCE
World Ocean Circulation Experiment, long term program/dataset of physical oceanographic measurements
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