Real - Time Deformation Monitoring of GPS Networks

Leoš Mervart, Zdeněk Lukeš,

Christian Rocken, James Johnson

Real-Time GPS ApplicationsTechnique Accuracy Observables

SPP 0.5 m – 30 m code

DGPS < 1.0 m code + (phase)

RTK1 – 3 cm (H)

3 – 6 cm (V)phase + (code)

RDRTK1 – 3 cm (H)

3 – 6 cm (V)phase + (code)

Reduced-Dynamic RTK (RDRTK)

assumption concerning the receiver motion

increased reliability of ambiguity resolution

longer baselines

Real-Time NETwork Software (RTNET)

Participants:

GPS Solutions Inc., Boulder, Colorado

Nippon GPS Solutions Corporation, Tokyo, Japan

Institute of Geodesy, TU Prague

RTNET – Menu System

RTNET Features-designed for real-time applications (running in post-processing mode possible)

-sophisticated algorithms for adjustment (stable filter) and ambiguity resolution

-statistically correct network adjustment (full variance-covariance matrix)

-written in C++ using object-oriented programming style

Server Mode:

-deformation monitoring

-real-time estimation of the troposphere

-generation of DGPS corrections, FKP corrections, and VRS data

Client Mode:

-PPP

-DGPS

-RTK on long baselines

GPS Solutions Inc.

Boulder, Colorado

Colorado Test Network

DGPS ApplicationStarFire

MS750

NGS(RTNET)

GEONET

Tokachi-Oki Earthquake

Tokachi-Oki Earthquake

Tokachi-Oki Earthquake

ConclusionsThe newly developed software RTNET is capable of resolving the wide-lane and narrow-lane ambiguities and to compute the receiver positions in RTK mode on ~100 km - baselines providing that the amplitude of motion does not exceed several decimeters. We called this application “reduced-dynamic RTK”.

  We used the new software for the processing of data stemming from the Japanese permanent GPS network GEONET. We processed the data collected during the Tokashi-Oki Earthquake in a mode that strictly corresponded to the real-time processing.

  The “reduced-dynamic RTK” clearly results show the oscillations of the GPS stations during the earthquake. The amplitudes of these short-periodic oscillations reach several decimeters and depend on the distance between the GPS receiver and the earthquake epicenter. The arrival of seismic waves at GPS stations is clearly visible. It demonstrates the feasibility of real-time GPS seismology.

- RTNET is routinely used at GSI for real-time monitoring of (part of) GEONET