Test evolution: RADARSAT-1 to RADARSAT-2
Test methodology for large spacecraft like RADARSAT-1 and RADARSAT-2 has been modified over the last decade resulting in changes to test environments. These changes in the required test environment have necessitated improvements in the test configuration modelling, instrumentation, and data acquisition systems. This paper will identify the significant changes and how the RADARSAT-2 assembly integration and test program has implemented these improvements.
RADARSAT-2 space segment design and its enhanced capabilities with respect to RADARSAT-1
RADARSAT-2, designed to be operational for 7 years, will provide continuity for the RADARSAT program. The RADARSAT-2 satellite design includes significant enhancements over its predecessors. The satellite features advanced radar imaging capabilities and will provide image data of the earth in a variety of spatial resolutions, polarizations, and incidence angles. This paper is intended to provide a top-level overview of the RADARSAT-2 space segment designed by MacDonald, Dettwiler and Associates Ltd. (MDA) in response to the requirements specified by the Canadian Space Agency (CSA). It provides the overview of each component of the space segment, such as the synthetic aperture radar (SAR) payload, the spacecraft bus, the extendible support structure (ESS), and the launch vehicle (LV). It also describes the major activities during spacecraft assembly, integration and testing (AI&T). The enhanced capabilities of RADARSAT-2 in comparison with those of RADARSAT-1 are highlighted throughout this paper.
Die Populationsdynamik Von Canthocampt Us Staphylinus (Jurine) (Copepoda, Harpacticoida) Im Litoral Des Bodensees
The population dynamics of Canthocamptus staphylinus in the littoral zone of Lake Constance are described (fig. 2). Adult animals aestivate as cysts. The main part of the population emerges from the cysts in autumn. During the resting stage and the first spell after emerging, mortality is very low (fig. 3). Reproduction, expressed as numbers of ovigerous females, begins in November and reaches its maximum in January. The new generation becomes adult in May/June and encysts without previous reproduction. According to Sarvala (1979) it may be possible, that in littoral populations dormancy is induced by long day periods and temperatures of over 12° C (figs. 1, 2). In the profundal zone C. staphylinus also forms cysts, however, both light and temperature are not likely to induce this stage in depths of over 60 m.