Final Report of BeJamDetect Project

On the 7* of July, one of the array antenna elements started to deliver much less signal power than
the other three elements. This was caused by malfunctioning of the 5V power supply of that active
array element. One of the effects of this power outtage was the systematically increased spread of
the eigenvalues and, as a consequence, a bias in the RFI detection metric. The start of the
appearance of this bias can be observed in Figure 4-23 on the 7* of July. Because the other three
array elements continued to operate normally, the RFI detection metric can still be used.
As can be observed in Figure 4-24 and Figure 4-25, the periods of increased RFI activity did not lead
to the disruption of Demonstrator 2. However, in the first (around the 7* of July) and the second
‘around the 14* of July) such periods some decrease of the number of GPS satellites used for PVT
and noticeable drop of the C/NO values can be observed and probably attributed to the interference
affect.

Time evolution of PRNs in PVT and in trac:

a va ] ll 1 l |
‚Au

|

R
=

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BA

Aa

Ta

ALL

AL...

MA
=

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an

N

ib

bu

= used for PVT
— tracked, GPS L1-C/A
— t'racked, GAL E1-B

UTC time

nl
28-Jul
2022

"Igure 4-24: Number of GPS L1-C/A signals being tracked and used for PVT, July 2022

Time evolution of mean CNO values

1GPS L1-C/A
E€1-B

(0

LS

ot

31

30

IF

3

14-Jui

UTC time

ZU

28-Jul

2022

Figure 4-25: Mean C/NO value for GPS L1-C/A signals, July 2022

Title: Final Report
Version: 1.0

age: 55