NavCom SF-3050 A Computationally Efficient Ambiguity Resolution User Manual

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Figure 5. RTK Navigation Results – Horizontal Position Scatter Plot

CONCLUSION

A new approach to the ambiguity resolution process has
been described. It is computationally efficient, in that a
simple process is used to compute the residuals without
first computing a position solution. Position solutions are
computed (also using a simplified process) only when the
residuals indicate the particular integer ambiguity
permutation has a high probability of being the correct
set. Using a wide-lane search before stepping to a narrow
lane search, is also efficient in that fewer permutations are
required to cover the same three-dimensional search
region. The frequency-weighted code combination
ensures a starting position with minimal multipath
corruption and the longer the search takes the better the
initial code solution becomes because of the code-
smoothing employed. As shown by the test results, the
search procedure is highly reliable and 80% or more of
the searches are successfully completed in a single epoch.

REFERENCES

1. Han, Shaowei, and Chris Rizos (1997). Comparing

FPS Ambiguity Resolution Techniques, GPS World,
vol. 8, no.10, pp.54-61.

2. Hatch, Ron, and Hans-Juergen Euler (1994).

Comparison of Several AROF Kenematic
Techniques, Proc. ION GPS-94, pp. 363-370.

3. Hwang, Patrick Y.C. (1991). Kinematic GPS for

Differential Positioning: Resolving Integer
Ambiguities on the Fly, Navigation, vol. 38, no. 1,
pp.1-15.

4. Pratt, M., B. Burke, and P. Misra (1997). Single-

Epoch Integer Ambiguity Resolution with GPS L1-
L2 Carrier Phase Measurements, Proc. ION GPS-97,
pp. 1737-1746.

NavCom RTK Navigation 24 Hours on a Stationary Point

-0.05

-0.04

-0.03

-0.02

-0.01

0.01

0.02

0.03

0.04

0.05

-0.08 -0.07 -0.06 -0.05 -0.04 -0.03 -0.02 -0.01

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Position Error East (meters)

Position Error North (meters)

1 cm

2 cm

East North Up

Average (cm.) -0.1 -0.1 0.4

Std. Dev. (cm.) 0.4

0.5 1.1

NCT2000D receivers
NCT2000A antennas

9 meter baseline