Whitepapers

Trimble ProPoint Engine: Next-Generation Centimeter Positioning and Orientation 5 measurement or correct the measurement. The method generally enables the provision of a precise position estimation even in the presence of measurements containing one or more outliers. Positioning modes ProPoint supports a variety of GNSS-only and GNSS/INS positioning modes. These include the following: ● Precise positioning: GNSS-SBAS, GNSS-DGNSS, GNSS-RTK, GNSS-RTX ● Precise positioning with orientation: GNSS/INS-SBAS, GNSS/INS-DGNSS, GNSS/INS-RTK, GNSS/INS-RTX Depending on the availability of differential corrections, the engine will gracefully transition positioning modes to deliver uninterrupted positioning. Integrated RTK xFill During periods of radio outage when the base station correction stream is unavailable to support conventional single-base or Virtual Reference Station (VRS) Network RTK, Trimble xFill ® correction service provides the technology that enables positioning to continue for short periods with centimeter-level precision. Not only does this eliminate positioning dropouts, it also enables a brief excursion into an area masked from the reference radio signal, yet still visible to the GNSS constellations. To achieve centimeter positioning with GNSS signals, Trimble xFill provides a specialized correction stream broadcast by L-band satellite that is generated using Trimble Real-time eXtended (Trimble RTX ® ) technology. The Trimble xFill technology is able to produce RTK positions with precision levels similar to traditional differential RTK because it mitigates the same source of errors. The satellite clock, orbit and measurement biases that are cancelled via differencing in standard RTK processing are modeled and transmitted as part of the Trimble RTX correction stream. These effects then become known quantities and can be properly accounted for when processing the rover measurements. The atmospheric errors are dealt with by algorithms specifically developed for the Trimble RTX system, reducing any residual effects to an acceptable level for high-accuracy GNSS positioning applications. As a result, the overall Trimble RTX data processing provides modeling of the residual errors on the satellite observations that are comparable to the ones achieved with RTK. Leverage CPU capacity in modern platforms As the number of GNSS signals increases, so does the computing power required to process all the measurements. To address this challenge, Trimble has released receiver platforms with upgraded processors and the latest Trimble Maxwell 7 GNSS ASIC (Application-Specific Integrated Circuit).

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