ISSN:0143-1161    

DOI:10.1080/01431168408948856

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A special enhancement algorithm is derived to colour separate ground-cover classes whose recorded wavelength distributions are similar but have significantly differing intensities. The special enhancement function is derived from considering the spectrum locus of a CIE 1931 (x,y) chromaticity diagram. By analogy with the relationship between the chromaticity co-ordinates and the channel radiance levels a function is derived that stretches the radiances to maximize the colour differences between such ground-cover classes. This Sinsusoidal Squeeze algorithm was applied to enhance the colour differentiation of Antarctic ice types as recorded by LANDSAT. A comparison between this special enhancement and the conventional colour composite results for Antarctic ice pack is presented. Field checks conducted during the 1980-81 Antarctic summer field season confirm our ability to delineate up to seven different types of ice by this technique. Additional applications of this special algorithm are believed to be forest class differentiation and bathymetric feature delineation.

ISSN:0143-1161    

DOI:10.1080/01431168408948857

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The utility of multispectral scanner subsystem (MSS) data has, in the last 10 years, proved to be of immense value in hydrologic investigations. Land-use thematic mapping and classification, as well as the identification of hydrologically significant basin physical parameters, are but a few of the many uses of LANDSAT data. Although the benefits have been many, certain problems continue to plague users. Classification attempts in small heterogeneous areas have often resulted in an inability to separate or differentiate the rapidly changing patterns, primarily due to the pixel size being larger than the individual surface parcels. The utility of MSS in small, highly urbanized basins containing complex land-use patterns is, therefore, somewhat limited, although spectral separation over larger, more spatially uniform areas has been highly successful. Another problem is misclassification due to the similarity in spectral response of many dissimilar surfaces such as urban and bare land, water and roads or other paved surfaces, and agricultural and residential areas. In addition, when several cover types of different spectral character are mixed throughout an area, the integrated signal is an average of the various surface features, thus indicating the presence of an entirely unrelated surface. LANDSAT MSS data of the Conley Creek basin near Atlanta, Georgia, was compared to thematic mapper simulator (TMS) data obtained the same day by aircraft. The TMS was found to alleviate many of the recurring problems associated with MSS data. Optimization of the band widths, an increase of the number of spectral bands to seven, an improvement of the ground resolution to 30 m has greatly improved the ability to distinguish features and the overall surface character. The TMS was able to detect numerous small water bodies, powerline rights-of-way, individual buildings and a variety of other features not visible on the MSS. In addition, the higher-resolution imagery could clearly distinguish between those areas which were improperly classified with the lower-resolution data.

ISSN:0143-1161    

DOI:10.1080/01431168408948858

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Our objective was to relate radiance measurements from a hand-held radiometer (Exotech 100-A) and an airborne muitispectral scanner (Daedalus DEI 1260) to different wheat (Triticum aestiuumL.) stand densities (simulated winter wheat winterkill) and to grain yield. The field experiment was located 11 km north-west of Sidney, Montana (47°45'N, 104°16'W) on a Williams loam soil (fine-loamy, mixed Typic Argiborolls). Three rates—67, 27 and 13 kg/ha—of ‘Len’, a semidwarf, hard red spring-wheat cultivar, were seeded to represent stands of 100, 40 and 20 per cent. Radiances were measured with a hand-held radiometer on clear mornings throughout the growing season. Aircraft overflight measurements were made at three growth stages: tillering, stem extension and heading period

ISSN:0143-1161    

DOI:10.1080/01431168408948859

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A simple model that describes the temporal behaviour of greenness is used to extract features to separate small grains from non-small grains. These features have previously proved effective in separating corn and soybeans. An additional feature derived from the temporal behaviour of the ratio of greenness to brightness has been found that aids in separating crops from non-crops. Using a very limited training set of 20 pure pixels per class obtained from ground data, the Ho-Kashyap linear classifier is trained on these derived features. The percentage of correct classification for pure pixels is about 85 per cent based on twenty-three 5nm × 6nm segments in Minnesota, North Dakota, South Dakota and Montana. The accuracy drops to 75 per cent for all LANDSAT pixels. An error in spring grain proportion estimate for all pixels (ground data classifier) of — 6.96 ± 7.85 per cent is found using this linear classifier. However, if segments with low small-grain proportion and strip fallow fields are removed, the error drops to —4.90±6.52 per cent. A considerable fraction of the bias arises due to the presence of impure (more than one class) pixels.

ISSN:0143-1161    

DOI:10.1080/01431168408948860

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The complexities and detail of urban scenes make it imperative that atmospheric effects are removed from satellite remotely sensed data prior to analysis. A study of atmospheric theory allows a simplified procedure to be developed for correction of multitemporal LANDSAT MSS scenes. Examples in the visible and near infrared, from a summer and winter scene, illustrate how disparate count values can be brought to good agreement as percentage reflectance.

ISSN:0143-1161    

DOI:10.1080/01431168408948861

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A language to describe Computer Compatible Tapes (CCTs) formats is presented. It is shown that all the information necessary to read a tape on a computer may be made up of two parts, (i) A few lines describing exhaustively the tape format in a top down manner; these notations could be used both for a general description of a format type and for a specification of a particular tape, on its shipment note or on its directory, (ii) A list indicating the position and format of the byte-strings containing important ancillary data. The language summary is included. Various CCTs formats and ancillary data lists of Coastal Zone Colour Scanner (CZCS), Heat Capacity Mapping Mission (HCMM) and LANDSAT are described using these notations.

ISSN:0143-1161    

DOI:10.1080/01431168408948862

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168408948866

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper introduces a new vertical coordinate, deduces the expressions of weighting function, and discusses the ability in measuring the middle atmosphere composition from high-resolution solar spectra. The results show that useful information on the constituents in the lower stratosphere can be given using modern conventional infrared spectrometers. However, for the measurements in the upper stratosphere and in the mesosphere, higher spectral resolutions are required.

ISSN:0143-1161    

DOI:10.1080/01431168408948867

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Future conservation efforts are expected to require population statistics for Southern Ocean species, including penguins. Preliminary laboratory spectral reflectance measurements are presented of penguin plumage plus some of the major components of the Antarctic environment. A sketch is presented of the prospects for employing remote sensing systems for monitoring penguin populations on a regional scale.

ISSN:0143-1161    

DOI:10.1080/01431168408948868

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor