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Übersicht:Das dargestellte Qualitätsmaß ist komplex. Sein Betrag ist maßgeblich für die Schwingstabilität des Oszillators, sein Phascmvinkel für die Amplitudenregelung, sein Imaginärtcil für die individuelle Rückkopplung des Verstärkers.Abstract: The presented qualifier is complex. Its absolute value is significant for the oscillation stability, its phase angle for the amplitude control loop, its imaginary part for the individual amplifier feedback.Für die Dokumentation: Oszillator / Frequenzstabilität / Rückkopplung / Amplitudcnregelung

Dasa (Daimler-Benz Aerospace) currently is in charge of an ESA contract for the PRISM feasibility study, including MATRA MS/France and SIRNUK. The main PRISM mission objectives are to monLor selected target areas with emphasis on bio-chemical stress analyses which are subject of changes such as vegetation, in particular deforestation, further areas include glaciers, land/water boundaries and similar. The Dasa study team makes widely use of a similar ESA instrument currently subject of dedicated subunits technology developments, the HRIS (High Resolution Imaging Spectrometer), also lead by Dasa. Its main features and technology developments will be covered in a survey.PRISM is covering most of the HRIS features, i.e. it will have an imaging spectrometer segment for the visible/NIR and the SWIR spectrum (450 -2350 nm) as HRIS, but implements four MIR and TIR channels to provide surface temperature data, represented by linear detector arrays (essentially the features of another currently pursued ESA development programme designated HRTIR). In a first study phase it also included a novel feature a wide-angle two-axis pointing system for along-and across-track pointing in order to yield multi-directional reflectance data of dedicated targets, which turned out to be the greatest design driver in the instrument, it was omitted in the later phases. The geometric sampling interval is defined to 50 m (design goal) at 50 km swath. PRISM is currently studied in a feasibility study in a competitive way by two teams, one being lead by Dasa. At the time of the Symposium both studies will be completed. The results of the Dasa team will be presented. Since PRISM covers most of the HRIS mission ft is rather likely that in case of a successful concept feasibilfty proof (performance and technology wise), it may later replace the HRIS instrument. It is anticipated that a major part of the technology developments currently performed for HRIS will be utilized -wfth some modifications -for PRISM as well.

MBB has started experimental work on three types of candidate optical sensors for Rendezvous & Docking (RVD) tasks, active laser diode radars, CCD cameras and position detector sensors plus combination of these. The result obtained until now with a test lab (including motion simulation) make each of them a promising candidate for this kind of applications for different range regimes. These sensors are conceived as multi-sensor head systems together with a central processing unit to provide applicability beyond docking of space platforms. A description of the sensors, their technical development requirements, achieved performance results and combination packages plus a proposal for in -orbit test missions is given in the paper.

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