In this letter, we simulate GNSS/LEO measurements and propose a process strategy for LEO-augmented GNSS medium length baseline RTK. Experiments show that, the performance of GNSS medium length baseline RTK can be significantly improved by introducing LEO satellites. The convergence speed of LEO-augmented GPS or BDS float solution maybe better than GPS/BDS combined under the conditions of similar satellite geometry. Besides, the RMS error of fixed solutions are improved to better than 4cm from sub-decimeter level.

We simulate some scenarios that 2/3 LEO satellites enhance 3/4/5 GPS satellites, to assess LEO-augmented GPS RTK positioning in signal-degraded environment. The effects of LEO-augmented GPS RTK in terms of reliability, availability and accuracy are presented, and the DIA algorithm is applied to deal with the poor data quality.