94 MPC User Manual Rev 0D
Appendix B GPS Overview
searching process can more rapidly and accurately home in on the correct lane when dual-frequency
measurements are available. Changes in the geom etr y of the sat ellites aids in ambiguity resolution;
this is especially noticeable in L1-only solutions. In summary, NovAtel’s RTK system permits L1/L2
receivers to choose integer lanes while forcing L1-only receivers to rely exclusively on the floating
ambiguity solution.
Once the ambiguities are known, it is possible to solve for the vector from the reference station to the
remote station. This baseline vector, when added to the position of the reference station , yields the
position of the r emote station.
In the NovAtel RTK system , the flo ating ambiguity and the integer position solutions (when both are
available) are continuously compared for integrity purposes. The better one is ch osen and ou tput in
the receiver’s matched-position logs. The “best” ambiguities determined are used with the remote
station’s local observations and a reference station observation model to generate the remote station’s
low-latency observations.