CYL AS-HYD 0R8282 - Caterpillar

AccuGrade GPS for Compactors
In order to produce RTK positions, two GPS receivers are required. One receiver is known as the GPS base station receiver. This receiver is in a known location and its exact coordinates are fixed and recorded. The other GPS receiver is known as the "rover". This receiver is located on the machine.In order to calculate an initial position solution, a GPS receiver must be able to receive signals from at least five satellites. Once the GPS receiver has calculated an initial position, the GPS receiver must be able to receive observations continuously from at least four satellites.Note: To compute the RTK fixed positions, the AccuGrade for Compactors System uses only satellites that are observed at both the base station and machine at the same time.The measurements that are sent from the base station are calculated for individual satellites. These measurements can only be used by the rover system in order to correct its measurements for the same satellites.The base station transmits its location, and the GPS\ measurements it makes at that location, to one or more machine-based GPS systems (rovers) that are working in the area where the base station is located. This permits the rover systems to generate corrections to the GPS system's measurements. The rovers use this information in order to calculate highly accurate positions.A GPS base station consists of the following components:
GPS receiver
GPS antenna
Radio
Radio antenna
Connecting cables
Power supply
Illustration 2 g01290166
A GPS base station is typically installed at a fixed or semi-permanent location such as the roof of the site office. Some sites use a mast with a permanently mounted GPS antenna. This configuration is shown in Illustration 2. Other sites are set up so that the GPS antenna can be easily removed from the mounting location.System Communications Overview
Illustration 3 g01304181
GPS and the AccuGrade System (5) GPS satellite constellation (6) Base station radio antenna (7) Base station GPS antenna (8) Rover receiver (9) Optional "Repeater" radio (10) Rover data radioAs depicted in Illustration 3, system communications are performed using a wireless data radio link. The wireless link consists of two data radios. One radio is located at the base station. This radio is known as the base station radio. The second radio is located on the machine. This radio is known as the rover radio.Both the base station GPS antenna (7) and the rover GPS receiver that is mounted on the compactor (8) perform simultaneous observations (measurements) of the GPS signals from the satellite constellation (5) .System communications are provided over a data radio link. The base station uses its radio (6) for broadcasting the observed information across the data radio link to either an "optional" repeater data radio (9), or else directly to the rover data radio (10) on the compactor. One base station can support an unlimited number of rovers, provided that the rovers are within 20 km (12.4 miles) of the base station.Note: 20 km (12.4 miles) is a nominal range based on ideal conditions.Note: Normally, the range of the data radio