absorption band: the wavelength range over which electromagnetic energy is absorbed by a material (e.g., a mineral, rock, or atmosphere) and has an emissivity less than 1.0
aerobraking: the process of reducing the initial elliptical orbit of a spacecraft around a planet to a nearly circular orbit by dipping the spacecraft into the uppermost atmosphere at the closest approach to the planet (periapsis). The drag created on the spacecraft during each pass progressively reduces the distance between the spacecraft and the planet at the farthest point in the orbit (apoapsis) until the orbit becomes nearly circular.
albedo: ratio of the amount of electromagnetic energy reflected by a surface to the amount of energy incident upon it
anhydrite: a sulfate mineral with the chemical formula of CaSO4
apatite: a phospate mineral with the chemical formula of Ca5(PO4)3(F,Cl,OH)
blackbody: an ideal material that absorbs all radiant energy incident upon it and emits radiant energy at the maximum possible rate per unit area at each wavelength for any given temperature. A blackbody has unit emissivity (emissivity of 1.0 across the entire spectrum).
calcite: a carbonate mineral with the chemical formula of CaCO3
chromite: an oxide mineral with the chemical formula of FeCr2O4
detector: a component within the instrument (e.g., TES, mini-TES, or THEMIS) that converts electromagnetic radiation into a recorded signal
diurnal: daily
dolomite: a carbonate mineral with the chemical formula of CaMg(CO3)2
electromagnetic radiation: energy propagated in the form of an advancing interaction between electric and magnetic fields, always moving at the speed of light
electromagnetic spectrum: continuous sequence of electomagnetic energy arranged according to wavelength or frequency
emission: the process by which a body radiates electromagnetic energy
emissivity: the ratio of radiant energy from a material to that from a blackbody at the same kinetic temperature. Materials may have wavelength-dependent emissivities between 0 and 1.0. (approximately the inverse of reflectance)
extended mission: a period of continued data acquisition following the end of the nominal, or mapping, mission
franklinite: an oxide mineral with the chemical formula of (Zn,Fe,Mn)(Fe,Mn)2O4
frequency: the number of wave oscillations per unit time or the number of wavelengths that pass a point per unit time
full spatial resolution: data returned from all six TES detectors
full spectral resolution: data returned from TES that include all 143 spectral data points (at 10 cm-1 sampling)
goethite: an oxide mineral with the chemical formula of alpha-FeO*OH
gypsum: a sulfate mineral with the chemical formula of CaSO4*2H2O
halite: a chloride mineral with the chemical formula of NaCl. Halite is commonly known as table salt.
hematite: an oxide mineral with the chemical formula of Fe2O3
ilmenite: an oxide mineral with the chemical formula of FeTiO3
incident energy: electromagnetic radiation impinging on a surface
infrared: region of the electromagnetic spectrum that includes wavelengths from 0.7 to 1000 microns
kinetic temperature: internal temperature of an object determined by random molecular motion; measured with a contact thermometer
kutnahorite: a carbonate mineral with the chemical formula of CaMn(CO3)2
magnesite: a carbonate mineral with the chemical formula of MgCO3
magnetite: an oxide mineral with the chemical formula of Fe3O4
mapping mission: the phase of the mission after aerobraking (or after orbit insertion if aerobraking doesn't take place) during which the spacecraft acquires the data planned for the mission (also sometimes called the "nominal mission")
mosaic: composite image made by piecing together individual images covering adjacent areas
near infrared: electromagnetic radiation ranging from 0.7 to ~3 microns in wavelength
nominal: as expected or planned; normal
orbit: path of a satellite around a body (e.g., Mars), under the influence of gravity
photon: minimum discrete quantity of radiant energy
picture element (pixel): in a digital image, the area on the ground represented by each digital number
pixel: see picture element
reflectance: ratio of the radiant energy reflected by a body to the energy incident on it (approximately the inverse of emissivity)
reflectivity: the ability of a surface to reflect incident energy (e.g., light-colored surfaces tend to have greater reflectivity than dark-colored surfaces)
resolution: ability to separate closely spaced objects in an image or phtograph
reststrahlen band: in the thermal infrared region, refers to absorption of energy as a function of (e.g.,) silica content
rhodochrosite: a carbonate mineral with the chemical formula of MnCO3
rutile: an oxide mineral with the chemical formula of TiO2
siderite: a carbonate mineral with the chemical formula of FeCO3
smithsonite: a carbonate mineral with the chemical formula of ZnCO3
solid solution: a single crystalline mineral phase which may range in composition anywhere between two endmember compositions. For example an Mg-Fe solid solution carbonate must contain both Mg and Fe, but the composition may range in chemistry anywhere between (but not including) magnesite and siderite
spatial mask: reduction of data returned from TES in which 1) two or more detectors have been averaged together, 2) not all six detectors were collected, or 3) a combination of 1) and 2). Spatial (and spectral) masks are used to reduce the amount of data returned to Earth.
spatial resolution: see resolution
spectral mask: reduction of data returned from TES in which not all 143 spectral data points (at 10 cm-1 sampling) are collected. This may be accomplished by 1) rejection of a data point from collection, or 2) averaging of adjacent spectral data points.
spectrometer: a device for measuring the intensity of radiation absorbed, reflected, or emitted by a material as a function of wavelength
spectrum: a plot of energy versus frequency or wavelength of light
sylvite: a chloride mineral with the chemical formula of KCl
thermal inertia: measure of the response of a material to temperature changes within a substance
thermal infrared: electromagnetic radiation ranging from ~3 - 50 microns in wavelength
visible light: electromagnetic radiation ranging from 0.4 to 0.7 microns in wavelength that is detectable by the human eye
wavelength: distance between successive wave crests (or other equivalent points) in a harmonic wave
reference: Remote Sensing by F. F. Sabins, Jr., 1987.
