ISSN:0143-1161    

DOI:10.1080/01431168908903896

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168908903897

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

For almost a quarter of a century, imagery and sounding data have been directly broadcast to users worldwide from polar orbiting satellites operated by the U.S. National Oceanic and Atmospheric Administration (NOAA). For more than a decade, almost the same payloads and data transmissions have been utilized. However, in the decade of the 1990s, several sensor improvements are planned or projected. This paper outlines payloads planned for NOAA Series spacecraft through the present century and the resulting changes in direct broadcast services.

ISSN:0143-1161    

DOI:10.1080/01431168908903900

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Tromso Telemetry Station has been in operation since 1967. The station worked very closely with ESRO (European Space Research Organization) until 1974. Since that time the TIROS-N satellites and the AVHRR-sensor (Advanced Very High Resolution Radiometer) have been the major data sources. Tromsø Telemetry Station is currently upgrading its capability to deliver preprocessed AVHRR data. The station will also be a major part of the ESA/Earthnet program for coordinated archiving and distribution of AVHRR data in Europe. A challenging aspect of the future of the station is the fact that it will become a national receiving station for ERS-1.

ISSN:0143-1161    

DOI:10.1080/01431168908903901

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Applications of AVHRR and optical satellite data at the Norwegian Hydrotechnical Laboratory (NHL) include studies of mesoscale eddies in the Norwegian Coastal Current, glacial outflow in fjords, snow hydrology, ice mapping and the motion of polar (atmospheric) lows. Geometrical parameters of mesoscale eddies were gathered from NOAA infrared images for the period 1981-1985 in connection with the study of large surface currents at the Troll Field. An algorithm for computing the phase speed of eddies along the coast was developed in order to estimate the magnitude of the surface currents. In situ, multi-frequency optical measurements in fjords have been tested against multi-frequency Landsat Thematic Mapper images. Surface fjord water laden with glacial till may have a visibility less than 10 cm. Estimates of the amounts of sediments in the surface layer may be made by remote sensing. Flow patterns of the colder melt water in fjords are also revealed by infrared images. A collaboration with the Norwegian Water Resources Board and the Norwegian aerial surveying firm Fjellanger Wideree is in progress to apply AVHRR remote sensing of snow fields to hydrologic models. Ice mapping is performed with data from NOAA, Landsat and SPOT satellites and stereo photogrammetry. NHL has joined several institutions in the U.K. and Canada for this study. Objectives include ice geometries, extent and forecasting. The motion of polar lows is one of the few all-weather applications of AVHRR data at NHL. The work was a joint venture with the Norwegian Meteorologic Institute.

ISSN:0143-1161    

DOI:10.1080/01431168908903902

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Earthnet's plan for a coordinated Advanced Very High Resolution Radiometer (AVHRR) data service in Europe, as outlined by Fusco and Muirhead (1987), is beginning to take'shape. Three High Resolution Picture Transmission (HRPT) stations are contributing to the data acquisition (providing coverage from West Africa to the Middle East and over the North Pole), the AVHRR catalogue is on-line and an autonomous workstation for AVHRR acquisition, processing and archiving to optical disc is in an advanced state of development.

ISSN:0143-1161    

DOI:10.1080/01431168908903903

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Limitations on the precision of digitized data are identified and discussed. Apart from calibration errors, these sources of uncertainty can be divided into three types of noise; digitization, Gaussian and periodic, each of which behaves differently when data is averaged. An attempt is made to separate and quantify these contributions in the infrared channels (3, 4 and 5) of various AVHRR instruments. Typical values of total noise for these channels are also obtained.

ISSN:0143-1161    

DOI:10.1080/01431168908903904

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Data from the 37 μm channel of the Advanced Very High Resolution Radiometer (AVHRR) are contaminated by interference which appears in the images as a herring-bone pattern. This interference has been present, to a greater or lesser extent, in the data from all six of the instruments which have flown to date. A measure of the quality of the imagery, estimated from the NOAA-7 and NOAA-9 instruments’ calibration data, is used to gain an idea of their progressive deterioration over each satellite's lifetime. The spectral properties of the Fourier transform of the data are examined and used to attenuate the unwanted components of the signal to an acceptable level. Two simple restoration algorithms are applied to a particularly severely contaminated NOAA-7 image and the resulting images presented.

ISSN:0143-1161    

DOI:10.1080/01431168908903905

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The gridding method for computing the geographical position of Advanced Very High Resolution Radiometer image pixels is based on a model that takes as input the TBUS mean orbital elements and an improved value of a parameter giving mean satellite speed. An accurate speed value can be found if the satellite is close to the equator at subsequent TBUS times. The resultant gridding errors found by comparison with Svalbard coastlines are attributed to scan line timing and satellite attitude. Errors are corrected by parallel displacements and images gridded to 1-2 km accuracy are used for ice mapping in the Fram Strait.

ISSN:0143-1161    

DOI:10.1080/01431168908903906

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper makes two contributions to the problem of geometrical rectification of Advanced Very High Resolution Radiometer (AVHRR) image data. The first is an automatic procedure for the location of ground control points (GCPs) without the involvement of operator intervention and using a library of 'chips’ of AVHRR data for the GCPs. The second involves the adaptation of a method previously used by Torlegard for Landsat Multi-spectral Scanner (MSS) data to the case of AVHRR data to attempt to achieve sub-pixel accuracy in the rectification; we have achieved an accuracy of 26 per cent of the pixel edge and have every hope that this can be reduced to below 20 per cent in the future.

ISSN:0143-1161    

DOI:10.1080/01431168908903907

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor