DE10344290A1 - Precision accuracy improvement e.g. for GPS via simultaneous use of ground and satellite based correction method, quality of correction data by simultaneous evaluation of satellite-based and terrestrial and uses increased correction data - Google Patents

Abstract

The system uses quality of the correction data by simultaneous evaluation of satellite-based and terrestrial and uses increased correction data to improve the positioning accuracy of navigation receivers.

Description

to Determining the position of moving and stationary objects in the terrain increasingly satellite-based Locating methods such as the Global Positioning System (GPS) used.

to Position determination is used at the location to be determined a multi-channel receiver, the receives several transmissions from satellites simultaneously. By Application of Correlation Procedure allows the recipient to Signal transit times from one's own location to the location of the different satellites on their orbits and thus the distance (pseudo orange) to the determine each satellite.

Out these ways the receiver calculates by using trigonometric relationships your own location.

Now if the propagation speed and evaluation of the signals is faulty, resulting in a positioning inaccuracy.

These Inaccuracy can be partially reduced by correcting signals into the navigation solution which are generated by a so-called reference station have been used to reduce the errors in the signal propagation times. This is called Difference GPS (DGPS)

To In the given state of the art, these correction signals either by transmission paths installed on earth sent from the reference station to the GPS receiver (Ground Based Augmentation System, GBAS) or by satellite-based transmission systems (Space Based Augmentation System, SBAS).

representative from SBAS in a broader sense are the European "European Ground Navigation Overlay System "(EGNOS) or the U.S. "Wide Area Augmentation System "(WAAS).

terrestrial Methods (GBAS) are, for example, the methods of SAPOS, via VHF such as RASANT, the above the FM radio is broadcast, or Systme the long-wave transmitter be broadcast.

problem area

Either terrestrial (GBAS) as well as satellite based (GBAS) correction systems can under the current state of the art only a limited availability provide the correction data.

So The GBAS methods rely on a transmitter network. The availability is so limited in the absence of coverage by a transmitter, in the range of the limit range and in case of breakdowns just this transmitter. The signals are also vulnerable to local extinctions (Fading) and local disturbances.

Space-based procedures EGNOS in turn use geostationary satellites for transmission the correction information. Due to the positioning of these satellites in the equatorial plane the earth can their emissions only with a clear view to the south and below in our latitudes comparatively shallow angles (about 30 °) are recorded. Im mobile This is often not the case given, reducing the availability is also limited to these emissions.

Of the This claim assumes that the probability the availability of terrestrial (GBAS) and satellite-based (GBAS) correction data distributions statistically independent are, since both on different physical and geometrical Conditions are based.

By simultaneous evaluation of satellite-based and terrestrial correction data can hence the availability and thus the quality of Data needed to improve the positioning accuracy of navigation receivers clearly increased become.

Experiments were carried out with the structure according to Fig 1 performed (s.Zeichnung).

At the entrance ( 1 ) the terrestrial correction signal (GBAS) is fed. It is handled by the receiving device ( 2 ) converted into processible form. The correction data are sent from the decoder ( 3 ) and the processing part ( 6 ).

At the entrance ( 4 ), the GPS signal and the correction information of the geostationary satellites (SBAS) is fed. In the present case, both signals are in the L band.

The receiver for the L-band signals ( 5 ) separates the navigation from the correction data. Under control of the processing part ( 6 ) the receiver either calculates the SBAS correction signals or the 6 ) Provided Terrestrial Correction Signals (GBAS) from the decoder ( 3 ) in the navigation solution.

The processing part ( 6 ) works under the control of the algorithm ( 7 ). This determines the selection of the correction data as a function of the availability, the quality of service and the temporal statistics of the respective correction data source.

Claims (1)

I claim for accuracy improvement of GPS by simultaneous use of ground and satellite-based correction method, characterized in that the availability and possibly quality of the correction data used to improve the positioning accuracy of navigation receivers is increased by simultaneous evaluation of satellite-based and terrestrial correction data.