Gps - sauter KERN SW 1000 Instruction Manual

2.6 GPS

The GPS antenna is located at the top of the sound pressure meters with GPS option.
☆ Note: Whether the GPS function is required must be known before delivery to the
user, otherwise you must send the sound pressure meter to the factory to install the
GPS module.
The GPS characteristics are influenced by two factors: the satellite ephemeris and the
signal-to-noise ratio of the satellite.
⚫ Satellite ephemeris: Orbit information from GPS satellites. The current location can
be determined from the ephemeris, the satellite position signal and the time. The
satellite ephemeris must be downloaded from the GPS satellite, but the download
speed is very low (about 50 bps) and depends on the signal strength of the satellite.
The high bit error rate can increase the download time for the ephemeris or cause
the download to fail completely. The sound pressure meter can store the ephemeris
for about 30 minutes after the GPS module is turned off. The ephemeris is only valid
for 2 hours.
⚫ Signal to noise ratio of the satellite: The strength of the satellite's position signal.
On rainy days or indoors, the signal strength is lower.
The GPS has 3 start modes: cold start, warm start and hot start
⚫ First positioning, the current ephemeris must be downloaded, therefore more time is
needed.
⚫ The GPS module has the last stored location information, but has to download the
ephemeris again because it is outdated. The warm start takes almost the same time
as the cold start.
The GPS module has valid ephemeris and can determine the position in a very
⚫
short time.
14 SW-BA-e-2020