Kharkov GPS Group

OCTAVA_PPA software testing results

This page presents the sample of  results of dual-frequency GPS/EGNOS (1 Hz) observations Pre-Processing&Analysis (PPA) concerning complete carrier-phase cycle slip repair and multipath estimation of code observations using the technique developed by the authors.

The processing is performed by the use of the software OCTAVA_PPA in MatLab. Here the processing results for two GPS satellites (SV9, SV26) (angle of masking 7⁰) and SBAS (S31) are presented.

 

GPS SV 9

Fig. SV9.1. Elevation angle function	Fig. SV9.2. Difference of code pseudoranges (P2-C/A) and its smoothing function
Fig. SV9.3. (L1-L2) LC* before processing	Fig. SV9.4. (L1-L2) LC** after carrier phase cycle slips repairing
Fig. SV9.5 - F** - function before processing	Fig. SV9.6 - F** - function after cycle slips repairing
Fig. SV9.7. Results of estimation of C/A code multipath effect	Fig. SV9.8. Results of estimation of P2 code multipath effect

 

GPS SV 26

Fig. SV26.1. Elevation angle function.	Fig. SV26.2. Difference of code pseudoranges (P2-C/A) and its smoothing function.
Fig. SV26.3. (L1-L2) LC* before processing	Fig. SV26.4. (L1-L2) LC* after carrier phase cycle slips repairing
Fig. SV26.5. F** - function before processing	Fig. SV26.6. F** - function after cycle slips repairing
Fig. SV26.7. Results of estimation of C/A code multipath effect	Fig. SV26.8. Results of estimation of P2 code multipath effect

*  LC - linear combination

** F-fuction - the "geometry-free" & "iono-free" function of "four observations". This unique LC is sensitive to the difference of L1 and L2 cyclic carrier-phase slips with wave length of difference frequency λ_WL=86,2 cm. F is complimentary to the LC (L₁-L₂) in case of arising of carrier-phase double slips including critical combinations of slips (ΔN₁λ₁-ΔN₂λ₂≈0)

 

SBAS (S31)

Fig. SBAS.1. Single difference of carrier-phase observations SBAS(S31) - GPS reference (SV15) satellite
Fig. SBAS.2. (L1-L1) increments  before processing	Fig. SBAS.3. (L1-L1) increments after carrier phase cycle slips repairing
Fig. SBAS.4. On this figure is presented the code - carrier difference (C/A-L1). As it is indicated in this figure, for a geostationary satellite (in contrast to GPS satellites) in this linear combination is practically absent a trend owing to the dynamics of the ionosphere delay. At the same time this linear combination contains a rather correlated over time oscillating component (multipath)