时间：2011-08-27 23:38来源：蓝天飞行翻译 作者：航空 点击：次
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Domain Specific Part An Addressing Authority is responsible for its own Addressing Sub domain, and NSAP Addresses within that addressing domain are distinguished, where necessary, by the value of the DSP. Domain(s) The domain of interest of an ARTAS Unit is the total geographical area in which the received surveillance information has to be processed for establishing the tracks; The domain of co-operation is made up with the overlapping parts of the domains of interest of two or more adjacent ARTAS units. The tracking continuity is executed in this domain; the domain of service continuity of an ARTAS unit is the geographical area in which this unit needs to be provided with tracks from adjacent units for the purpose of both tracking and service continuity; the user domain of interest is, for a given user of an ARTAS unit, the geographical area in which the required track information service shall be provided Doppler Shift An apparent change in the frequency of a signal caused by relative motion between the transmitter and the receiver. Doppler Speed The radial (to the radar sensor) velocity of a target (aircraft) or of a clutter source (false alarm) measured from its Doppler frequency shift in a received primary radar return. Downlink Associated with signals transmitted on the 1090 MHz reply frequency channel. Downstream Air Traffic Service Unit An ATS Unit responsible for control of an airspace region through or near which the aircraft will progress at some time in the future. Driving force The external contextual environmental forces impading an organisation which may be predetermined or uncertain. Drop (rate) See Track Drop Rate. Duplicate Extractor Monitoring Message If an EMM is received before (Mean antenna Revolution time -30%) AND (45' of the expected EMM position) a Duplicate EMM condition exists. Duplicated Secondary Surveillance Radar Coverage Duplicated SSR coverage means that for a given point in space, the radar data used by an ATS unit for the surveillance function are derived from at least two independent Secondary Surveillance Radar (SSR) sources working simultaneously. D-Value The amount (positive or negative) by which the altitude (Z) of a point on an isobaric surface differs from the altitude (Zp) of the same isobaric surface in the ICAO Standard Atmosphere (i.e. D-value = Z minus Zp). Dynamic Data Environment Data subject to on-line changes, for which default values cannot be predefined. Dynamic Database Database which contains Dynamic Data to be used by automated ATS functions. Tip: to find a specific term, use the Acrobat search : click D on the binocular icon in the window bar menu |
