ISSN:0143-1161    

DOI:10.1080/01431169308904378

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Landsat TM images were analysed to assess the scope and limitations of their use for inland water quality detection. The spectral information in the six visible to middle infrared bands is discussed. The relatively wide spectral bands, 1 to 4, of the TM, in the optical wavelength domain contain a mixture of spectrally opposing features of absorption and scattering

ISSN:0143-1161    

DOI:10.1080/01431169308904379

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

With fluorescence lidar operated from aircraft a nearly synoptic investigation of hydrographic conditions in the surface layer of the sea is achieved. Raman and fluorescence spectroscopy allow a registration of spectral attenuation coefficients as well as concentrations of chlorophyll-^ and gelbstoff (DOM, Dissolved Organic Matter). In particular gelbstoff can be used as a natural tracer for the identification of water types and frontal systems in coastal areas.

ISSN:0143-1161    

DOI:10.1080/01431169308904380

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Sea surface temperatures (SSTs) have been derived operationally at the National Remote Sensing Agency using NOAA AVHRR data since early 1991. The channel 4 temperature variations in the sunglint area and its surroundings are presented. The SSTs derived using satellite data with those of ship observations are compared in the sunglint area. The errors in sea surface temperature estimations using satellite data in an area of sunglint are described.

ISSN:0143-1161    

DOI:10.1080/01431169308904381

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper investigates radar cross-section (RCS) characteristics of rain- and wind-roughened sea-surfaces. We conducted experiments in laboratory wind-wave tanks using artificial rain. The study includes light rain rates, light wind speeds, and combinations of these. A 36 Ghz scatterometer was operated at 30° incidence angle and with vertical polarization. RCS data were obtained not only with the scatterometer pointing up-wind but also as a function of azimuthal angle. We use a scatterometer rain and wind model SRWM-1, which relates the total average RCS in storms to the sum of the average RCS due to rain plus the average RCS due to wind. Implications of the study for operational monitoring of wind in rainy oceanic areas by satellite-borne instruments is discussed.

ISSN:0143-1161    

DOI:10.1080/01431169308904382

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

During the last six years we have carried out a series of ground-based microwave measurements on agricultural fields. Bare soils, corn (maize), wheat, sugar-beet, potatoes, grass, canola (rape), oat, and rye were observed under various conditions and phenological stages. Our calibrated radiometer-scatterometer system, RASAM, operates at frequencies between 3 and 11 GHz. The brightness temperature was measured at horizontal and vertical polarization, and the back scattering coefficient at HH, W, HV, and VH polarization, all at incidence angles from 0° to 70°. In addition we measured soil and vegetation parameters. The data are stored in our signature data base.

ISSN:0143-1161    

DOI:10.1080/01431169308904383

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Oceanographic data (Ecofer, Givapa and Gastel cruises) and satellite images evidence that the channels 1 and 2 (visible and near infra-red regions) of AVHRR/NOAA-11 can be used to estimate the total concentration of suspended sediments on the sea surface, with a daily frequency when under cloudless skies. The near infra-red channel is used for atmospheric corrections. The fit function obtained between the concentrations determined by filtration and the corrected satellite data is linear between 0-5mgl -1 and lOmgl-1. The satellite data are also compared to ship data scattering measurements. The results match.

ISSN:0143-1161    

DOI:10.1080/01431169308904384

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The normalized difference vegetation indices (NDVIs) deduced from multi-date NOAA-11 AVHRR/2 Local Area Coverage data have been used to generate growth profiles of 1989-90 Rabi (winter) sorghum in the tehsils of the three major sorghum growing districts, Ahmadnagar, Pune and Solapur, in Central Maharashtra, India. Spatially large and contiguous sorghum cultivation sites have been used to characterize sorghum. The crop growth equation suggested by Badhwar was used to model profiles. The tehsil average yields were regressed on the growth parameters, including senescence rate in early post-anthesis period for enabling pre-harvest forecasting (in model-1), and area under the complete growth profile (in model-2). The model-1 enables issuing of pre-harvest forecast of yields at least 45 days in advance.

ISSN:0143-1161    

DOI:10.1080/01431169308904385

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simple physically-based method for estimating the daily surface outgoing longwave radiative flux during cloudless days is presented. The proposed algorithm is well-suited for remote sensing purposes, in the framework of surface net radiation and evapotranspiration studies: it only requires the NOAA-AVHRR derived surface temperature acquired in the early afternoon, the minimum air temperature easily obtainable from the meteorological network, and the day-length computed from the site coordinates and the date. The algorithm features one single empirical coefficient, adjusted statistically on a large data set generated by a coupled heat and mass transfer model between the soil and the atmosphere. The method is then validated against ten different experimental data sets, covering a wide range of surface, climate and weather conditions. The validation is performed at the daily and five-day scales and is shown to lead to a good precision. The sources of errors are then discussed and a map of the surface outgoing longwave radiation flux established from a NOAA-AVHRR image is finally presented.

ISSN:0143-1161    

DOI:10.1080/01431169308904386

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Image processing of Thematic Mapper data in the Schist-Greywacke Complex (Central Iberian Hesperian Massif, Spain) suggests effects connected to both thermal metamorphism and shear-zone related dynamic metamorphism. Fabric analysis on thin section of rock samples define more intensive deformation in areas with distinct spectral features in the imagery. This is confirmed by ground structural data and laboratory spectra of soil samples. Laboratory spectra in the visible and near-infrared on different surfaces of the same sample, referring to its fabric elements, offer differences in reflectance. Dark rocks present a more favourable response to weak dynamic metamorphic effects on reflectance. The quantity and quality of organic matter content in rocks is believed to be responsible for changes in reflectance corresponding to effects produced by thermal metamorphism and dynamic metamorphism. Thus, reflectance shown by imagery and laboratory data proves to be a useful tool for mapping areas with different deformation intensity and variable attitude in space of structural elements as a guide line in exploration of structural variations for geological mapping.

ISSN:0143-1161    

DOI:10.1080/01431169308904387

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor