摘要:

MOMS-02 is a push-broom scanner with four spectral bands in the 450–810 nm region (each with a 15 m ground resolution element at a 310 km orbit) and a panchromatic (520–760 nm) stereo mode with on-track stereoscopic capability. The stereo mode employs three look angles: nadir (with a 5 m ground resolution element), 24° forward and backward (each with a 10 m ground resolution element). The sensor which is funded by the German Ministry for Research and Technology (BMFT) is scheduled for launch on a Space Shuttle mission at the end of 1991. The selection and radiometric performance of the panchromatic and the multispectral bands are discussed.

ISSN:0143-1161    

DOI:10.1080/01431168908903978

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A spatial co-occurrence algorithm has been used to derive image texture from Landsat Multispectral Scanner (MSS) data to increase classification accuracy in a moderate relief, boreal environment in eastern Canada. The aim was to investigate ‘data-driven improvements’, including those available through digital elevation modelling. Overall classification accuracy using MSS data alone was 59·1 per cent when compared to a biophysical inventory of the area compiled primarily by aerial photointerpretation. This increased to 66·2 per cent with MSS plus texture and to 89·8 per cent when MSS data were analysed with geomorphometry extracted from a digital elevation model (DEM). The introduction of MSS texture resulted in statistically significant increases in individual class accuracies in classes that were also well defined using the geomorphometric and integrated data sets. This suggested that some of the additional information provided by geomorphometry was also contained in spectral texture. It was also noted that individual texture orientations resulted in higher class accuracies than average texture measures; this is probably related to structural (slope/aspect) characteristics of specific vegetation communities.

ISSN:0143-1161    

DOI:10.1080/01431168908903979

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Radiometric measurements of a cotton canopy exposed to long term moisture stress are compared with those obtained using the technique of suddenly induced moisture stress. It is shown that the results obtained from both techniques are broadly similar. It is also demonstrated that the changes in reflectance in the near-infrared are closely related to changes in leaf hydrostatic tension. Since changes in leaf hydrostatic tension are used to trigger irrigation applications, this opens up the possibility of using field radiometry as a tool in irrigation water use planning.

ISSN:0143-1161    

DOI:10.1080/01431168908903980

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Multispectral (XS) image data recorded by the High Resolution Visible (HRV) sensor aboard the SPOT-1 satellite are being evaluated for the mapping of Arctic tundra vegetation in the Arctic Foothill Province of Alaska. This research is part of a current ecosystems study that requires an efficient means for mapping vegetation types over large areas. Conventional spectral-based image classification techniques were applied to SPOT/HRV-XS data from a single date. The unique characteristics of the vegetation cover (mainly tussock tundra) and illumination conditions of the location necessitated a detailed examination of classification approaches that have generally been applied in mid-latitude studies. Preliminary results suggest that areal estimates of Arctic tundra vegetation types can be made accurately (±2·5 per cent per category), but maps generated by classifying spectral features of SPOT/HRV-XS data alone arc unsuitably accurate (56 per cent). This is partly due to the high occurrence of relatively small vegetation parcels, determined by measuring the characteristic lengths of vegetation parcels from a ‘ground reference’ map covering the same area as the SPOT/HRV-XS subscene.

ISSN:0143-1161    

DOI:10.1080/01431168908903981

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor