Spread Spectrum; Figure 2.5 Pacific Crest Uhf/Vhf Rover Receiver - ashtech Z-Xtreme System Manual

receiver. Figure 2.5 shows a typical rover receiver.

Figure 2.5 Pacific Crest UHF/VHF Rover Receiver

The UHF and VHF radios offered in the ZX SuperStation are manufactured by Pacific
Crest Corporation.

Spread Spectrum

RTK surveys conducted on small project sites not exceeding 2 km between base and
rover systems can utilize spread-spectrum radios. An advantage of spread-spectrum
radios is the license-free operation. No FCC license is required to operate them since
spread-spectrum radios are limited in power output to only 1 watt. In addition, areas
with a great deal of radio traffic in the UHF or VHF frequencies can make it difficult to
perform RTK surveys if the radios being used are close to the same frequency. Since
spread-spectrum radios function at a much higher frequency and utilize a frequency
hopping scheme, they are not affected by the traffic. Figure 2.6 shows a spread-spec-
12 Real-Time Kinematic Surveying