SX BLUE GPS iSXblue II+ GNSSTM, User Manual

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SXblue Series User Manual 61
Various types of post-processing can be performed: Static, semi-kinematic,
kinematic, code-phase, phase, using L1 only or L1/L2, GPS only or GNSS, with a
local base station or using PPP. Refer to the post-processing software
documentation for recommended occupation times to achieve the highest possible
performance.
2.9 Evaluating the SXblue Performance
The SXblue receiver performance has been evaluated with the objective of
determining best-case performance in a real-world environment. Static testing has
shown that the SXblue achieves a performance better than 60cm 95% of the time
when using SBAS signal (WAAS, EGNOS, GAGAN or MSAS) and better than 3cm
when using a reliable RTK signal.
The qualifier of 95% is a statistical probability. Often you may see manufacturers
using a probability of ‘rms’ or standard deviation. Performance measures with
these probabilities are not directly comparable to a 95% measure since they are a
lower probability (less than 70% probability). This means that less often, a product
would position within a radius of the prescribed amount.
The following table summarizes the common horizontal statistical probabilities.
Table 2-2 Horizontal Accuracy Probability Statistics
Accuracy Measure Probability (%)
RMS (root mean square) 63 to 68
CEP (circular error probability) 50
2dRMS (twice the distance root mean square) 95 to 98
R95 (95% radius) 95
It is possible to convert from one statistic to another using the following table. Using
the value where the ‘From’ row meets the ‘To’ column, multiply the accuracy by
this conversion value.
Table 2-3 Horizontal Accuracy Statistic Conversions
To
CEP RMS R95 2dRMS
F
ro
m
CEP 1 1.2 2.1 2.4
RMS 0.83 1 1.7 2.0
R95 0.48 0.59 1 1.2
2dRMS 0.42 0.5 0.83 1