European Facility For Airborne Research April 4, 2025, 16:57
LAI: Leaf Area Index. Ratio of green leaf area per unit soil area.
level 0 (processing level): Data transcription from system file format to a standardized, readable and generic data format to be archived as raw data.
level 1 (processing level): Level 1 is instrument data, either in digital counts or in units of at-sensor radiance, appended with ancillary information like calibration coefficients and geolocation information per pixel. Sub-levels (L1a, L1b, L1c...) are open to specific definitions per provider.
level 2 (processing level): Geometric, radiometric and atmospheric corrected surface data. Reflectance, temperature and emissivity, although not directly measured, are considered level 2. Sub-levels (L2a, L2b, L2c...) are open to specific definitions per provider.
level 2 atm (processing level): Derived from the Level 1 product, the data converted to ground surface reflectance values after atmospheric correction.
level 2 geo (processing level): Derived from the Level 1 product and geometrically corrected (orthorectified) and re-sampled to a specified grid.
level 3 (processing level): Level 3 is any image that contains a geophysical variable not directly measured by the instrument, but are derived from its measurements (except for reflectance, temperature and emissivity, which are considered Level 2). Level 3 products contain thematic information extracted from hyperspectral data, ready to interpret.
line scanner: A scanning radiometer which by use of a rotating or oscillating plane mirror can scan a path normal to the movement of the radiometer. The mirror directs incoming radiation to a detector, which converts it into an electric signal.
line spread function (LSF): A measure of the geometrical performance of an optical system which defines the apparent shape of a target as it appears in the output image. A plot of illuminance of the image as a function of distance in the image plane.
LUT: A Look-Up Table (LUT) is a data structure often used to replace a runtime computation with a simpler array indexing operation.