accessibility__skip_menu__jump_to_main

Full text: BeJamDetect Project

Final Report of BeJamDetect Project 
1OC 
M.of-N detection metrics, L1 band 
St 
300 
250 
= 200 
a. 
ant2 
ant3 
ant4 
ant5 
ant6 
-ant7 
Mrashold 
50C 
50 | 
:00 
5 
400° 
350 
or 
5 
M-of-N detection metrics, L1 band 
-ant 1 
— ant2 
ant3 
—— ant4 
— ant5 
ant6 
- — ant7 
threshold‘ 
Z 
Fol 
2X 
SO 
S{ 
00 N 
500 1000 1500 2000 2500 23000 3500 
test block number (each of 1500 samples} 
4000 
IC 
„3 1000 1500 2000 2500 3000 23500 4000 
test block number (each of 1500 samples} 
a) Nominal case June 01, 2021 at 07:38:21 MET b)RFI case June 01, 2021 at 20:00:31 MET 
Figure 3-7: M-of-N detection metric 
The main test metric for classifying the potential interference event in the n-th recording is the 
increase of the received IF power of the antenna array central (top) element with respect to its 
“ominal value: 
PıinCn) ) 
APinasn) = 1010g E(Paınnom) 
41) 
The received power on the outputs of the RF-front-ends is estimated by using the digital signal 
samples. The estimation of the absolute power was not pursued because it would require the 
calibration of the entire receiving signal path. Instead, an increase of the received power is 
considered to be a manifistation of the presence of an RFl-signal that raises the received power 
level in the corresponding frequency band. The nominal power level without interference, i.e. when 
only the thermal noise dominates each output of the RF-front-ends, is estimated by using records 
without RFI signals detected. The estimation of the nominal power level is further improved by 
averaging over many recordings E(Pınnom), e.9. over all snapshots within a given month or longer 
time period. This estimation is performed for each array element because the signal gain varies 
from one antenna plus RF front-end channel to another. However, only the metric obtained for the 
central (top) element of the array was used for the RFl-event categorisation (see Figure 3-8). The 
metrics obtained from other array elements were used to estimate the RFI-signal direction of arrival. 
Based on the increase of the received power, the RFI events are categorized into three groups as 
follows: 
RFI strength 
\Weak 
Medium 
Strong 
Input power increase 
Above 1dB and bellow 3dB 
Above 3dB and bellow 5dB 
Above 5dB 
"able 1 — Radio-frequency interference event strength classification 
Title: Final Report 
Version: 1.0 
302!
	        
Waiting...

Note to user

Dear user,

In response to current developments in the web technology used by the Goobi viewer, the software no longer supports your browser.

Please use one of the following browsers to display this page correctly.

Thank you.