GPS works with weak signals. The signal strength on earth is approximately 15dB below the thermal noise floor. In order to design a reliable GPS enabled system, the following parameters have to be considered carefully during the design phase as they may significantly degrade the GPS performance.
- Antenna shortcommings
- Poor Gain fo the GPS antenna
- Poor directivity(radiatin pattern) of the GPS antenna
- Improper orientatin of the antenna to the sky
- Poor matching between antenna and cable impedance
- Poor noise performance of the receivers input statge or the antenna amplifier
- Electrical Environment
- Jamming form external signals
- Jamming form signals generated by re receiver itself
- GPS related effects
- Signal path obstruction by building, foliage, covers, snow,etc
- Multi-path effects
- Satellite constallation and geomatry