How the GPS-Receiver Works
The satellite Global Positioning System (GPS) distributes precise time, frequency and position worldwide. At a height of about 20,000 km satellites circle around the earth on different orbits. An atomic clock (accuracy at least 1 x 10 E-12) is running in every satellite whose time is constantly transmitted together with the orbit data. The GPS-receiver records the data of up to 6 satellites and uses this information to calculate its position. The transmitted orbit data are used to determine the travel time of the signals of the individual satellites. These values form the basis for a very precise GPS-time which is maintained in the system via an adjustable crystal at an accuracy of ± 1 µsec.

Systems
Our GPS-radio controlled clocks can be used worldwide as time standards. We offer interfaces with RS232-, RS422-, TTY-, IRIGA- and IRIGB outputs, boards for PCs and (on request) for VME-bus computers. Furthermore, our production line includes systems for the supervision and analysis of frequencies, standard frequency generators, master and slave clocks.

Installation
All devices are configurable. At any location in the world on every continent, the difference time to UTC and regional changeover times for summer/wintertime can be entered. A integrated simulation of the DCF77-signal enables DCF77-clocks to be synchronized worldwide without alterations in well proved installations.

Technical Data
GPS Receiver
- 6 channel C/A-code-receiver
- analysis of the position and determination of the UTC time with output of a comparison time marker.

GPS Analysis
- Calculation of the local time
- Management of changeovers
- Administration and service functions
- Internal crystal control for bridging of transmission failures

GPS Antenna
- Micro-stripline antenna with pre-amplifier

Accuracy
- ± 1 µsec. during GPS reception
- ± 0.1 ppm time drift during free running and constant temperature
- Backup clock during voltage failure ± 25 ppm at 25°C

Extras
Antennas, antenna cables, indirect lightning protection, & line amplifier hopf GPS-receivers operate worldwide in a wide variety of applications. Reference clocks operate e.g. in the USA, South Africa, China, India and Australia. For operation within Europe our DCF77-receiver can be used.