Final Report of BeJamDetect Project 
) DLR 
5. Demonstrator 3 
5.1. Hardware used 
The hardware used by Demonstrator 3 is very similar to the hardware used by Demonstrator 1. This 
due to the fact that the development of the miniaturised GALANT took place more slowly as 
axpected at the beginning of the project. The extension of the miniaturised platform to a dual- 
frequency operation was not available within the time-frame of the project and the decision was 
taken to use the “large” GALANT platform for realising the dual-frequency interference 
monitoring. 
The changes in the hardware set-up of Demonstrator 3 with respect to Demonstrator 1 are as 
follows: 
a dual-frequency L1/L5 receiver from uBlox of Neo F10T series was added into the setup in 
arder to provide post-correlation test metrics in real-time. Such metrics are, for instance, 
Z/NO0 values, number of satellites in track and used for PVT as well as jJamming and spoofing 
detection flags. The detection flags are especially helpful in terms of collecting experience 
with using such built-in features of commercial receivers and assessing their usability under 
different RFI conditions. The uBlox receiver was connected via USB to Nutaqg platform, 
where a python code was permanently executed for receiving the uBlox observables in the 
oroprietary ubx binary format and re-send them to the GUI via a TCP/IP link; 
a notebook Windows-PC is used in the role of the display device of an especially developed 
tailored GUI for Demonstrator 3. Because of the availability of post-processing well-proved 
Matlab tools used with Demonstrator 1, the GUI was developed in Matlab environment. 
Though this allows for high flexibility and enables relatively short development time, the 
axecution of the Matlab and GUI requires significant computational power and limits the 
choice of possible operational systems to Windows, macOS and Linux. 
5.2. Interference detection using real-time graphical interface 
The GUI of Demonstrator 3 was designed to receive and evaluate the following data: 
Snapshots of raw IF digital samples recorded by GALANT (i.e. Nutag) platform. These data 
were used in the following ways: 
Power spectrum density (PSD) plots are computed for both L1 and L5 frequency 
bands; 
Spectrograms are computed for L1 and L5; 
GNSS acquisition is performed for GPS and Galileo signals on L1 and L5 in order to 
zompute the steering vectors to the corresponding satellites and evaluate the 
spatial-domain spoofing detection metric that tests the spatial diversity of the 
steering vectors; 
The GNSS acquisition results for the self-generated calibration signals are used to 
calibrate the phase of the individual antenna channels of the system; 
Fitle: Final Report 
Version: 1.0 
age: 75