摘要:

A method to derive evapotranspiration from a combination of satellite and conventional data is investigated. For this purpose NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) infrared images on clear days of various seasons are used to derive surface temperatures over France. These temperatures are then compared to the shelter-height temperatures collected at the WMO (World Meteorological Organization) standard meteorological stations at the time of satellite overpass. The difference between the two temperatures varies both with season and latitude. To analyse those results we use a model of the soil-vegetation interface, forced by a reconstruction of the surface fluxes derived from the WMO data. The model simulates reasonably well the diurnal and seasonal variations in the difference between satellite surface temperature and surface-air temperature. The corresponding latitudinal variations which occur in summer may be interpreted in terms of evapotranspiration. The limitations of this method are determined by a model sensitivity study; in particular they are due to the role played by tall vegetation.

ISSN:0143-1161    

DOI:10.1080/01431168708954796

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

An atmospheric correction scheme using Landsat Thematic Mapper (TM) bands 1, 2 and 4 was developed and the data corrected for atmospheric effects due to Rayleigh scattering and aerosols. Secondly phytoplankton pigment mapping was achieved through substitution of corrected radiances in TM bands 1 and 2 into a bio-optical algorithm developed for the study area off Azhikal in the Arabian Sea. A C map showing near-surface concentrations of phytoplankton pigments (mgm−3)and a K map showing the pigment distribution (m−1) in one attenuation length were generated.

ISSN:0143-1161    

DOI:10.1080/01431168708954797

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Image data recorded from SPOT-1 were correlated with five forest stand parameters: mean percentage canopy cover, tree density, mean tree diameter at breast height (DBH), mean tree height and sub-compartment age. With the exception of percentage canopy cover, the correlation coefficients for the near-infrared waveband (S3) were all significant at the 99 per cent confidence level. The correlation coefficients for the red (S2) and green (S1) wavebands were lower and this may be due to the low dynamic range of the data for forest canopies in these wavebands.

ISSN:0143-1161    

DOI:10.1080/01431168708954798

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor