000			03194nam a22003737a 4500
999			_c150610 _d150610
003			CR-SiIICA
005			20230430065900.0
007			ta
008			220316t2023 ||||| |||| 00| 0 eng d
040			_aCR-SiIICA _bspa
041			_aeng
100			_aMaurent, Eliott _eautor _9349416
245			_aMulti-sensor airborne lidar requires intercalibration for consistent estimation of light attenuation and plant area density
260			_bElsevier _c2022
270			_aSan José, C.R.
300			_a1 recurso en línea (14 páginas) _bpdf
362			_a1 de Marzo, 2023
520			_aLeaf area is a key structural characteristic of forest canopies because of the role of leaves in controlling many biological and physical processes occurring at the biosphere-atmosphere transition. High pulse density Airborne Laser Scanning (ALS) holds promise to provide spatially resolved and accurate estimates of plant area density (PAD) in forested landscapes, a key step in understanding forest functioning: phenology, carbon uptake, transpiration, radiative balance etc. Inconsistencies between different ALS sensors is a barrier to generating globally harmonised PAD estimates. The basic assumption on which PAD estimation is based is that light attenuation is proportional to vegetation area density. This study shows that the recorded extinction strongly depends on target detectability which is influenced by laser characteristics (power, sensitivity, wavelength). Three different airborne laser scanners were flown over a wet tropical forest at the Paracou research station in French Guiana. Different sensors, flight heights and transmitted power levels were compared. Light attenuation was retrieved with an open source ray-tracing code (http://amapvox.org). Direct comparison revealed marked differences (up-to 25% difference in profile-averaged light attenuation rate and 50% difference at particular heights) that could only be explained by differences in scanner characteristics. We show how bias which may occur under various acquisition conditions can generally be mitigated by a sensor intercalibration. Alignment of light weight lidar attenuation profiles to ALS reference attenuation profiles is not always satisfactory and we discuss what are the likely sources of discrepancies. Neglecting the dependency of apparent light attenuation on scanner properties may lead to biases in estimated vegetation density commensurate to those affecting light attenuation estimates. Applying intercalibration procedures supports estimation of plant area density independent of acquisition characteristics.
650		0	_aAGRICULTURA _94
650		0	_9148332 _aFORESTS
690			_9351276 _aAIRBORNE LASER SCANNING
690			_9351277 _aESCANEO LÁSER AEROTRANSPORTADO
690			_9351278 _aALS
690			_9351279 _aPLANT AREA DENSITY
690			_9351280 _aDENSIDAD DEL ÁREA DE LA PLANTA
690			_9157067 _aPAD
690			_9351281 _aLAD
700			_ay siete autores más
773			_aRemote Sensing of Environment
856			_qpdf _yeng _fBCO23019191 _uhttps://repositorio.catie.ac.cr/handle/11554/12229
942			_2z _cART
942			_2z _cDIG