飞行翻译_公务机_公务航空_Business Jet_Business Aviation

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Control segment (ground); and

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User segment.

 NAVIGATION SYSTEMS Description  Vol. 2  17.10.73 
Oct 05/06 

Space Segment
The space segment of the GPS is made up of 24 NAVSTAR satellites. There are 21 operational satellites at all times, and three are spares. The satellites:
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Are in a 10,900-mile-high orbit;

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Are in six orbital planes, with four satellites in each plane;

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Have a 12-hour orbit;

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Are spaced to provide a minimum of 4 satellites in view at all times; and

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Have atomic clocks, and transmit on two coded frequencies.

Control Segment
The control segment monitors the space segment, and adjusts the orbits when operationally required. It includes five ground stations around the world. One is the master control station and the others are monitor stations.
The monitor stations passively track all satellites in view and acquire range data from them. This data is forwarded to the master control station. The master control station uses the data from the monitor stations to estimate satellite orbit and clock data. This information is transmitted to the satellites and down to the users as a navigation message.
User Segment
The FMS uses the signal from the GPS satellites as a navigation sensor to upgrade its own position. A minimum of three satellites is required for two-dimensional calculations, and four satellites are required for three-dimensional calculations.
Components and Operation
GPS Receivers
Dual GPS receivers are installed in the Challenger 605 (GPS 1 and GPS 2). The GPS receivers process signals from the orbiting constellation of GPS satellites to determine geographic position. Each of the GPS receivers is capable of receiving up to 12 satellites. Tuning is fully automatic, and does not require any pilot input/action.
GPS 1 is powered by the battery bus, and GPS 2 is powered by DC bus 2.

GPS Sensors and Navigation
The flight management system (FMS) is the interface between the GPS receivers and the aircraft navigation systems. GPS position information is supplied to each FMS by the on-side GPS receiver (GPS 1 supplies FMS 1, and GPS 2 supplies FMS 2). The FMS then calculates the integrated navigation solution (FMS position) using a combination of GPS, DME/DME, VOR/DME, and IRS sensor information.
In the event that on-side GPS information is not available, the FMS will automatically use cross-side information, and display the GPS REVERTED message on the FMS CDU.

 NAVIGATION SYSTEMS Description  Vol. 2  17.10.74 
Oct 05/06 

GPS RAIM
GPS Receiver Autonomous Integrity Monitoring (RAIM) is used to assure that the GPS position information meet the required accuracy:
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4 NM oceanic/remote;