To perform the most precise relative positioning using GPS, it is necessary to resolve the carrier-phase integer cycle ambiguities. This process becomes increasingly difficult as the distance between the mobile and reference GPS receivers increases, due to the decorrelation of the GPS errors with distance, resulting in a practical limit on the distance over which ambiguity resolution can be per...

[1] We present the first two aircraft Global Positioning System (GPS)-reflection altimetry measurements, the most precise GPS ocean-altimetry measurement, and demonstrate the altimetric precision and spatial resolution necessary to map mesoscale eddies. Our first experiment demonstrated a 14-cm precision single-satellite ocean altimetry measurement while our more recent experiment demonstrates ...

Outdoor applications for small-scale Unmanned Aerial Vehicles (UAVs) commonly rely on Global Positioning System (GPS) receivers for continuous and accurate position estimates. However, in urban areas GPS satellite signals might be reflected or blocked by buildings, resulting in multipath or non-line-of-sight (NLOS) errors. In such cases, additional onboard sensors such as Light Detection and Ra...

By direct georeferencing, i.e. the direct measurement of the exterior orientation of an imaging sensor using an integrated system consisting of receivers of the Global Positioning System (GPS) and a strap-down Inertial Measurement Unit (IMU), many applications can be realized more efficiently and economically due to the reduction or elimination of required ground control and tie point informati...

The integrated GPS/INS/PL system, with complementary characteristics to overcome the shortcomings of each individual part, can be achieved at different levels, namely loosely, tightly or ultra-tightly coupled. The next generation of integrated GPS/INS/PL navigation systems will be based on the ultra-tight coupled method. Ultratight coupled system offers numerous advantages, such as improved hig...

In our study, we analyzed the combined standard uncertainty of water table slope assessment done using differential global positioning system (DGPS)-based measurements of water table elevation and distances between measurement locations. We compared and discussed uncertainties in water table slope assessments done in various hypothetical environments of lowland floodplains (water table slopes t...

Successful GPS operations are based on a basic equation: the range measurement equation, |rr(tr) – rs(ts)| = c(tr –ts), in an earth-centered inertial (ECI) frame, corrected for range biases. The calculations utilizing this equation show that (1) the speed of light is independent of the source’s translational motion relative to the ECI frame if the receiver is stationary; (2) the speed of light ...