Raven INVICTA 115, Инструкция по установке и обслуживанию

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DIFFERENTIAL GPS (DGPS) WAAS
DGPS works by placing a high-performance GPS receiver (reference station) at a known location.
Since the receiver knows its exact location, it can determine the errors in the satellite signals. It does
this by measuring the ranges to each satellite using the signals received and comparing these measured
ranges to the actual ranges calculated from its known position. The difference between the measured
and calculated range is the total error. The error data for each tracked satellite is formatted into a
correction message and transmitted to GPS users. The correction message format follows the
standard established by the Radio Technical Commission for Maritime Services, Special Committee
104 (RTCM-SC104). These differential corrections are then applied to the GPS calculations, thus
removing most of the satellite signal error and improving accuracy. The level of accuracy obtained is
a function of the GPS receiver. WAAS is based on a network of approximately 25 ground reference
stations that cover a very large service area. Signals from GPS satellites are received by wide area
ground reference stations and used to generate DGPS corrections.
Differential GPS Broadcast Site
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