Antenna phase center position deviation

GPS receiver equipment errors include observational error, the receiver clock error, the antenna phase center error and carrier phase observations uncertainty affect the whole week.

The observation error observations to distinguish between error and receiver antenna relative to the placement error of the measurement site.

Based on experience, is generally believed that the observed resolution error of about 1% of the signal wavelength. Therefore, know that the carrier phase resolution error than the code phase is not small, this error is a random error, may be appropriate to increase the observations will be significantly weakened its impact.

Receiver antenna relative to the placement error of the observatory center, the main antenna set is not taken in error and the amount of antenna error in precision positioning work must be serious, careful operation, in order to minimize this error impact.

Although GPS receivers high precision quartz clocks, its frequency stability can reach 10 -11 square, but the impact on the carrier phase observation can not be ignored.

Deal with the receiver clock error is more effective method is the difference between the observation time of the receiver clock as is relevant, thereby establishing a clock error model, and that for a time in the form of the polynomial, then the measurements Adjustment calculation of the uniform solution, the coefficients of the polynomial, and thus the receiver clock error correction.

The most sophisticated methods of observation commonly used in the carrier phase observations, the receiver can only be measured carrier phase non-fractional part of the whole week, and direct determination of the number of weeks of the opening wave phase, and thus there are whole weeks of uncertainty.

In addition, the cycle slip phenomenon occurred in the observation process, due to the loss of lock of satellite signals. Signal from the satellite lost lock to the signal re-lock on the carrier phase non-fractional part of the whole week had no impact, is still consistent and lose lock, but the whole number of weeks is interrupted rather than continuous, cycle slips on observations similar to the entire week of the unknown, the precision positioning, data processing, the whole week is unknown and cycle slips are key issues.

GPS positioning, observation is the receiver antenna phase center position to prevail, and thus the antenna phase center with its geometric center is theoretically consistent. But, in fact, the antenna phase center position with the strength and direction of the signal input change, ie, observation of the instantaneous position of the phase center (called as the phase center) with the theoretical center of the unit position will vary deviation of the antenna phase center relative positioning results, according to the pros and cons of the antenna performance, up to several millimeters to several centimeters. For precise relative positioning, this effect can not be ignored.

In practical work,Main products: car dvd player and car dvd , are with good quality.  if you use the same type of antenna, not far from two or more observatories, simultaneous observation of the same group of satellites, and then can be Differenced to weaken the impact of the phase center offset. Need to mention is that the placement of each station's antenna, Yi are attached to the antenna azimuth standard orientation, so that according to the compass point to magnetic north.