Topcon HiPer Ga, Operator'S Manual

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Introduction
HiPer Ga/Gb Operator’s Manual
1-6
– Satellite Based Augmentation Systems (WAAS, EGNOS, and
so on) creates and transmit, along with DGPS corrections,
data integrity information (for example, satellite health
warnings).
– Current ephemerides and almanacs.
Conclusion
This overview simply outlines the basics of satellite positioning. For
more detailed information, visit the TPS website at
www.topconpositioning.com.
Receiver Overview
When power is turned on and the receiver self-test completes, the
receiver’s 40 channels initialize and begin tracking visible satellites.
Each of the receiver’s channels can be used to track any one of the
GPS and GLONASS signals. The number of channels available
allows the receiver to track all visible global positioning satellites at
any time and location.
An internal GPS+ antenna equipped with a low noise amplifier (LNA)
and the receiver’s radio frequency (RF) device are connected with a
coaxial cable. The wide-band signal received is down-converted,
filtered, digitized, and assigned to different channels. The receiver
processor controls the process of signal tracking.
Once the signal is locked in the channel, it is demodulated and
necessary signal parameters (carrier and code phases) are measured.
Also, broadcast navigation data are retrieved from the navigation
frame.
After the receiver locks on to four or more satellites, its absolute
position in WGS-84 and the time offset between the receiver clock
and GPS time are computed. This information and the measurement
data are stored in the receiver’s internal memory
and can be
downloaded later onto a computer, then processed using a post-
processing software package. When the receiver operates in RTK
mode, raw data measurements can also be recorded into the receiver’s