The size of the DOP value is proportional to the GPS positioning error. The greater the DOP value, the greater the positioning error, and the lower the positioning accuracy. PDOP directly reflects the distribution of GPS satellites. When the PDOP is large, it indicates that the geometric distribution of the 4 GPS satellites in the sky is not ideal. The circumference of the graph formed by them is too short, and the positioning accuracy is low, and vice versa.
The attenuation of precision factor (DOP) is an indicator of position quality. It is a calculation result that considers the position of each satellite relative to other satellites in the constellation (geometric position) to predict the position accuracy that can be obtained with the constellation. A small DOP value indicates a higher probability of a strong satellite geometric position and accuracy. A high DOP value indicates a weak satellite geometric position and a lower probability of accuracy.
Use the geometric precision factor (DOP, dilution of precision, also translated as the attenuation of precision factor) to measure the impact of the spatial geometric distribution of the observation satellite on the positioning accuracy. DOP is divided into the following categories:
PDOP (position dilution of precision) three-dimensional position precision factor: the root value of the sum of squares of errors such as latitude, longitude and elevation.
TDOP (time dilution of precision) clock precision factor: the offset error value of the time meter in the receiver.
HDOP (horizontal dilution of precision) horizontal component precision factor: it is the root value of the square sum of errors such as latitude and longitude.
VDOP (vertical dilution of precision) vertical component precision factor The
conversion relationship is:
HDOP2+VDOP2=PDOP2
PDOP2+TDOP2=GDOP2