# The most detailed explanation of P-10 Pro accuracy.

P-10 Pro can provide horizontal accuracy 0.5m/CEP(50%) and 1.5m/CEP(95%).

CEP refers to Circular Error Probable. 0.5m/CEP(50%) means that the probability of the track points falling within a 0.5m radius is greater than 50%; 1.5m/CEP(95%) means that the probability of the track points falling within a 1.5m radius is greater than 95% .

In “static” scenarios, to acquire 0.5m/CEP (50%) accuracy, please follow the below prerequisites:

1. Put the device in an open environment: no trees above, no tall buildings around.
2. “Placement” and “time convergence” are the key factors to obtaining an accurate reading. Place the antenna receiving surface (front) of the P-10 Pro horizontally upward. Wait for the position to slowly converge .Please let the device stand still for a period of time(the convergence of GNSS) – we recommend waiting at least 15 minutes for convergence. Take the average value of the position.

In “dynamic” scenarios, the offset distance is the same as the ones in “static” scenarios, which is, there is a 50% chance that the offset distance will be within 0.5m.  With a 95% chance of being within 1.5m. The dynamic trajectory will show that the trajectory as a whole shifts in one direction (the offset position and direction are unpredictable though).

#### Actual Position Difference vs. CEP values

CEP refers to the radius of the circle error.  Within a circle, the maximum distance between two points is diameter. Which means the maximum distance between 2 P-10 Pro reading points could be at most 1 m when CEP is 50%, and 3m when CEP is 95%.

This implies that 5% of the chances, 2 reading points difference could be over 3m. To minimize inaccuracy, allow some time for GNSS convergence.

#### Measure the accuracy

Columbus has an official method to measure the accuracy of P-7 Pro.
https://cbgps.com/p7/app/gnsstoolkit/cep/index_en.htm

The same method can be used to measure the accuracy of P-10 Pro. Just connect the P-10 Pro to a computer by using a USB cable. P-10 Pro works in receiver mode.  And you can test the P-10 Pro accuracy by following the P-7 pro test instructions.