TEQC multipath metrics in MATLAB

Abstract

Knowledge of the local direction of multipath at a particular site is important for a number of reasons. For example, such information can be used to study site selections or during monument design for GPS installations. We present a MATLAB program for creating colorized polar maps of high-frequency multipath using TEQC report files of single-epoch data. The maps, although not necessarily indicating the actual local direction of multipath on the ground, give the orientation with respect to the geometry of the satellites in the sky. This information can aid the interpretation of ground multipath geometry at the site. We give an example of short-span data with 0.05 Hz multipath (i.e. repeat period % 20 s) although the program can be modified for long-term measurements as well.

Quality assessment of FORMOSAT-3/COSMIC and GRACE GPS observables: analysis of multipath, ionospheric delay and phase residual in orbit determination

“…Multipath effect may be severe for F3/C due to the way the solar panels are deployed and the use of patch antennas. We determined the multipath effects of code on F3/C and GRACE using the computer program TEQC (Estey and Meertens 1999;Ogaja and Hedfors 2007). TEQC is designed for quality analysis of GPS/ GLONASS data and has the following functions http://facility.unavco.org/ software/teqc/teqc.html: (1) translation of GPS data from a binary format to a RINEX (The Receiver Independent Exchange Format) format (Gurtner 1994), (2) editing GPS observations, including data selection, metadata extraction and the title revision and (3) quality check (QC) of observation.…”

Mapping GPS multipath: a case study for the lunar laser ranger timing antenna at HartRAO

“…The second limitation involves MP1 and MP2 being a measure of pseudo-range precision, which is highly dependent on smoothing algorithms, the antenna used, and firmware changes of the receiver (Ray and Senior, 2003). A good example to visualise multipath is given by Ogaja and Hedfors (2007), where they developed a MATLAB program for creating colourised polar maps of high-frequency multipath using TEQC report files. …”

Multipath and multipath reduction in the obstructed areas by using enhanced strobe correlator (ESC) technique

“…Although the term multipath is used to describe these derived values, other factors are also influencing the results as well as multipath. They include things such as receiver noise and residual ionospheric delay that has not been completely removed from the formed linear combination [2,3,5,7].…”

“…From a practical point of view, these correlators can significantly reduce multipath error. However, the short-delay multipath error is not efficiently mitigated [1,3,4,5,6]. …”

“…It computes the MP1 and MP2 linear combinations using both pseudo range and carrier phase data to eliminate the effects of station clocks, satellite clocks, troposphere delay and ionospheric delay. In practice, the constant part of MP1 and MP2 is removed so that TEQC actually reports the root mean square (RMS) variation of MP1 and MP2 for each satellite, as well as a mean RMS for all satellites [5].…”