Final Report of BeJamDetect Project 
4.4. Results of RFI detection and characterisation 
The results presented in this chapter are obtained by analysing the logs of the GALANT array 
receiver collected durng the measurement campaign that was conducted from 03-May-2022 till 
11-July-2023. The logs contain standard NMEA ASCII messages like GSV, GGA, RMC as well as 
several DLR-proprietary messages. The information available through the receiver logs can be 
summarised as follows: 
UTC time stamp of the observations data-set; 
estimated WGS-84 coordinates and speed over the ground; 
course over the ground; 
number of satellites used for PVT; 
status of individual satellite tracking channels of the receiver: PRN tracked or acquired, 
Doppler, C/NO, elevation, azimuth; 
status of direction estimation: PRN, elevation, azimuth; 
attitude of the antenna array estimated by using GNSS signals in the form of [roll, pitch, 
yawl; 
pre-correlation array covarlance matrix. 
These information is updated with the rate of 2 Hz, ie. every 0.5 sec. 
The results of the analysis of the collected data are presented and discussed in the following on the 
jamming month-per-month basis. 
4.1.1. Interference situation in May 2022 
Below in Figure 4-13 - Figure 4-16 presented are the main metrics used for characterising the 
interference situation in May of 2022: 
mean carrier-to-noise density value (C/NO) computed for all GPS L1-C/A and Galileo E1-B 
satellites tracked by the receiver at a time; 
number of satellites being tracked and used for the PVT solution at a time; 
3FI detection metric computed on the eigenvalues of the array covariance matrix. The array 
covariance matrix is computed here by using the array signals taken before the de-spreading 
process, l.e. before executing PRN-code correlation in the individual satellite tracking 
channels of the receiver. 
55 
Time evolution of mean CNO0 values 
— 
50 
15 
L 
40 
35 | 
0 
Fr 
-—=GPS L1-C/A | 
— GALE1-B | 
— _ AV A EL KL KL“ 
06-May 09-May 12-May 15-May 18-May 21-May 24-May 27-May 30-May 
UTC time 2022 
-igure 4-13: Mean C/NO value for GPS L1-C/A signals, May 2022 
Title: Final Report 
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