摘要:

One month of the Advanced Very High Resolution Radiometer (AVHRR) Global Area Coverage (GAC) Land Pathfinder (AGLP) data from September 1985 are used to examine the spatial and temporal distribution of fires over four major ecosystems in South America. The Earth Radiation Budget Experiment (ERBE) scanner data are used to examine the top of atmosphere (TOA) shortwave and longwave fluxes over smoke generated from biomass burning. The relationship between the AGLP-derived Normalized Difference Vegetation Index (NDVI) and the ERBE-estimated clear sky albedos are also examined as a function of the four ecosystems. This study shows that the grassland areas in South America have the highest number of fires for September 1985, and their corresponding NDVI values are smaller than the tropical rainforest region where the number of fires were comparatively small. Clear sky statistics accumulated during the days when smoke was not present show that clear sky albedos derived from ERBE are higher for grassland areas when compared to the tropical rainforest. The results show that the AGLP can be used to determine the spatial and temporal distribution of fires along with vegetation characteristics, while ERBE data can provide necessary information on broadband albedos and regional top of atmosphere radiative impacts of biomass burning aerosols. Since the AGLP data are available from 1981 to the present day, several climate-related issues can be addressed.

ISSN:0143-1161    

DOI:10.1080/014311697217521

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Airborne videographic remote sensing is a relatively recent technology that can provide spatial data for a variety of forest management issues. This letter presents a methodology which demonstrates that videographic data can accurately predict the complexity of fauna habitat across forested landscapes at two metre resolution. This provided an excellent tool for stratifying the forest into fauna habitats to predict the composition, spatial distribution and abundance of faunal groups.

ISSN:0143-1161    

DOI:10.1080/014311697217530

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The effects of non-orthogonality of trihedral corner reflectors are significant when the reflector dimensions are large compared to the wavelength. Therefore, a high frequency approach is adopted combining geometrical and physical optics. A simple frequency dependent relationship is proposed for the maximum cross-section loss due to a given angular uncertainty. Polarization purity and phase stability are also addressed.

ISSN:0143-1161    

DOI:10.1080/014311697217549

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Indices for the non-destructive estimation of chlorophyll content were formulated using various instruments to measure reflectance and absorption spectra in visible and near-infrared ranges, as well as chlorophyll contents from several non-related species from different climatic regions. The proposed new algorithms are simple ratios between percentage reflectance at spectral regions that are highly sensitive (540 to 630nm and around 700nm) and insensitive (nearinfrared) to variations in chlorophyll content: R NIR / R 700 and R NIR / R 550. The developed algorithms predicting leaf chemistry from the leaf optics were validated for nine plant species in the range of chlorophyll content from 0.27 to 62.9mug cm -2. An error of less than 4.2 mugcm -2 in chlorophyll prediction was achieved. The use of green and red (near 700nm) channels increases the sensitivity of NDVI to chlorophyll content by about five-fold.

ISSN:0143-1161    

DOI:10.1080/014311697217558

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

An experimental procedure for the determination of suspended sediment concentration in stratified river plumes, using Thematic Mapper data, has been set up and tested by numerical computation.

ISSN:0143-1161    

DOI:10.1080/014311697217567

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/014311697217576

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor