ISSN:0149-0419    

DOI:10.1080/15210609409379715

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

At the Alfred Wegener Institute for Polar and Marine Research, several geodetic methods are used to map the seafloor in polar regions. Multibeam bathymetric surveys are regularly conducted in polar regions by the institute's icebreakerPolarstern.These multibeam data are combined with bathymetric data from other sources to create bathymetric maps. The Hydrosweep multibeam system on thePolarsternis presently being modified to have a wider survey swath and the ability to collect sidescan and backscatter data. These modifications will enable researchers to survey the seafloor more efficiently and will provide important information about the seafloor materials. Satellite altimetry data is also used to supply the correlation between the earth's geopotential field and the seafloor topography. This correlation can be used to guide bathymetric contouring in areas with little or no bathymetric data. Current efforts involve the study of ERS‐1 altimetry data from the Weddell Sea, Antarctica, where the altimetry data are being used to aid bathymetric mapping.

ISSN:0149-0419    

DOI:10.1080/15210609409379716

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper reports on results obtained from the GEOSAT altimeter over the Ekströmisen ice shelf, adjacent to the eastern margin of the Weddell Sea, Antarctica. The Ekströmisen ice shelf, on which the German wintering station Neumayer (formerly Georg‐von‐Neumayer) is established, is the main working area of German polar research activities. Measurements carried out by the GEOSAT altimeter between 1987 and 1989 were used in this study in order to determine ice shelf heights for mapping the Ekströmisen ice shelf. The processing and analysis of altimeter measurements over the Ekströmisen ice shelf indicate good height determination over flat ice sheets, with an accuracy of less than ±1 m depending on the characteristics of the ice surface.

ISSN:0149-0419    

DOI:10.1080/15210609409379717

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The three‐dimensional evaluation of ocean wave photographies by means of digital image matching yields the same results as an analytical plotting of the same photos. This will be demonstrated on the basis of an example with deep water waves photos. The deducted power spectra from the three‐dimensional model are in agreement with the results from traditional swell measuring methods.

ISSN:0149-0419    

DOI:10.1080/15210609409379718

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Two different types of differential global positioning systems (DGPS) are used for precise positioning and navigation. The “ordinary”; DGPS combines range corrections from a reference station with carrier smoothed pseudoranges at the moving station. This method works on a routine basis and provides accuracies of down to I m or even less. The precise differential GPS concept (PDGPS) uses carrier phase observations of both stations and requires an ambiguity resolution while the user platform is moving. This technique provides accuracies of 0.1 m or less, but it is much more difficult to realize. Within this paper both concepts are discussed and presented in examples. In particular, the limitations and chances of the PDGPS technique and the possibility of its operational use are critically investigated.

ISSN:0149-0419    

DOI:10.1080/15210609409379719

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The Federal Republic of Germany has carried out several marine research expeditions including multibeam surveys by the research vesselPolarsternin the southern Atlantic Ocean. Since the bathymetry of the Weddell Sea, Antarctica, is insufficiently known, the Alfred Wegener Institute for Polar and Marine Research (AWI) is preparing bathymetric maps for this region.

ISSN:0149-0419    

DOI:10.1080/15210609409379720

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0149-0419    

DOI:10.1080/15210609409379721

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

B. Hofmann‐Wellenhof, H. Lichtenegger, and J. Collins.GPS Theory and Practice.

ISSN:0149-0419    

DOI:10.1080/15210609409379722

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0149-0419    

DOI:10.1080/15210609409379714

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor