摘要:

This paper compares nearly 3000 wind-vector estimates derived from the scatterometer on SEASAT-A with in situ observations made by ships and buoys during the JASIN experiment. The Jet Propulsion Laboratory, Pasadena, have reprocessed the satellite wind data with the latest available algorithms using a subset of the JASIN observations; this comparison uses data from 132 SEASAT passes over the whole 62 days of JASIN. For winds between 4 and 18 m/s, the satellite accuracy was 1·7 m/s in speed and 17° in direction, well within the design goal of 2 m/s and 20°. Further analysis dividing the data according to the value of various parameters, such as polarization or swath position, shows that the design criteria were met in nearly all these subcategories

ISSN:0143-1161    

DOI:10.1080/01431168408948814

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

SEASAT's ability to measure surface wind and wave fields over the area of the Joint Air-Sea Interaction experiment (JASIN) by means of its radar altimeter, microwave radiometer, scatterometer and synthetic aperture radar (SAR) has been analysed over some eight passes selected to provide a variety of surface conditions from light winds (4m/s) to moderately strong winds (16-20m/s). Comparisons were made not only with observations from research vessels and buoys but also between one SEASAT sensor and another. It is concluded that a description as accurate as surface observations but with considerably better resolution was achieved.

ISSN:0143-1161    

DOI:10.1080/01431168408948815

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Hydrological interest in mapping snow concentrates on the phase of snow depletion when at least part of the snow cover is wet. In this situation, snow has a very low backscatter coefficient, smaller than almost any land surface at X-band. Together with the independence of cloud cover and time, this unique signature of snow enables frequent and regular mapping of snow even in rugged terrain. First results from a synthetic aperture radar experiment made during the melting season—even under unfavourable conditions—clearly indicate this potential.

ISSN:0143-1161    

DOI:10.1080/01431168408948816

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A semiquantitative method has been developed for the classification of lowland forest terrain in Colombian Amazonia. The method, which makes use of SLAR imagery at a scale of 1:200 000, is hierarchic in character and provides for the recognition of up to seven terrain classes. The morphological evolution of the landscape is discussed in the light of preliminary terrain mapping.

ISSN:0143-1161    

DOI:10.1080/01431168408948817

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A geologic interpretation of a 1:500 000 scale mosaic of optically correlated Seasat SAR imagery showed that 14 of the 17 major units mapped by the Geological Survey of Iceland could be recognized although it was not possible to close all the radar geologic boundaries. Interactive work with computer correlated imagery produced no additional information significant to mapping at that scale. Comparison with Landsat revealed that the radar produced more data on ice type, alluvial categories and upon lineaments but the overall interpretative value of Landsat was clearly the better of the two. The results of local co-registering Landsat and Seasat were interesting but did not cause any modification of the regional interpretation

ISSN:0143-1161    

DOI:10.1080/01431168408948818

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The like polarized and the depolarized backscatter cross sections for composite rough surfaces are evaluated using the full wave approach as well as a perturbed physical optics approach. The full wave approach which accounts for both specular point and Bragg scattering in a self-consistent manner is expressed as a weighted sum of two cross sections associated with the large-scale and small-scale spectral components of the rough surfaces, respectively. Provided that the assumed condition for deep phase modulation is satisfied, the full wave solution for the total backscatter cross section is insensitive to the precise choice of the wavenumber where spectral splitting is assumed to occur. The solution based on the perturbed-physical, optics approach is shown to be suitable even for moderately large mean square slopes provided that the angle of incidence is larger than 30°.

ISSN:0143-1161    

DOI:10.1080/01431168408948819

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168408948820

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168408948822

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168408948823

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168408948824

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor