Beitler, Anton and Tollkuhn, Andreas and Giustiniano, Domenico and Plattner, Bernhard
CMCD: Multipath Detection for Mobile GNSS Receivers.
In: International Technical Meeting of The Institute of Navigation, 26 - 28 January 2015, Dana Point, California.
In recent years, the rising demand for high precision
localization has challenged the use of GNSS particularly
in automotive applications. This is especially the case in
urban scenarios where the most crucial GNSS disturbance
is multipath – the reception of reflected signals. This work
addresses the detection of multipath errors in pseudorange
measurements for the special case of a moving receiver
without the need for redundant observations or motion sensors.
Our proposed detection scheme is based on a combined
observable we call CMCD (Code-Minus-Carrier
Deltarange). It is defined as the difference between
code- and carrier-derived deltaranges and approximately
resolves to the derivatives of the receiver noise and the code multipath error. The CMCD-based detection algorithm
exploits the fact that the CMCD observable is equal to the
receiver noise process for multipath-free environments.
Simulations of a two ray multipath model show that the
code multipath error can be described as a broadband
noise process in case of a moving receiver and an abrasive
reflection surface. This additional noise process causes
changes in the statistical properties of CMCD and hence
indicate multipath occurrences. A statistical test is used to detect these changes.
With a test drive under heavy mutlipath conditions the
detection performance was evaluated and the suitability of
CMCD-based multipath detection was shown. The results
indicate a correlation between multipath detections and high
ranging errors. In addition, the horizontal position error
with a set of 4 satellites was evaluated. In cases of at least one multipath-affected pseudorange a resulting position error of around 15 m (CEP95) and above was observed. With measurements detected as multipath-free the resulting error was around 5 m (CEP95).
Conference or Workshop Papers
||05 Mar 2015 15:03
||15 Dec 2016 15:13
Actions (login required)