Intruder Monitoring

by DARC e.V. Germany in the european area of IARU region 1

About Intruder Monitoring

The Intruder Monitoring of the DARC (formerly "Bandwacht") deals with unauthorised use of the shortwave amateure radio bands by foreign radio services.

At the same time, it serves the radio amateur community as a reporting centre and in this function receives reports on band intruders. On this basis, it consolidates the information and, if necessary, initiates official steps to shut down the illegal transmissions.

Unauthorised use of the amateur radio bands occurs if a foreign station uses the 40-, 20-, 17-, 15-, 12- or 10-metre bands, since according to the international telecommunications agreement, these bands are exclusively allocated to amateur radio.

In the following picture you can see three Intruders covering a wide range of the 40 metre band in summer 2021:

Legal basis

The Intruder Monitoring of the Deutscher Amateur-Radio-Club e. V. (DARC) is the German branch of the International Amateur Radio Union Monitoring System (IARU-MS) according to the IARU Resolution 12-1 "Terms of reference for the IARU Monitoring System".

Our cooperations

We have close contacts with various authorities that we can directly address and involve, including offices of the radio measurement service of the german PTT (BNetzA).

Unter dem nebenstehenden Link finden Sie unsere deutschsprachige Website.

General services


Our Automated Radio Monitoring (ARM) operates 24/7 with a fully automated realtime listening station located in Germany. The system consists of several antennas and software defined receivers (SDR, Winradio G33DDC) as well as the software go2signals by Procitec running on a powerful server.


The radio analysis service is also based on the latest software.
Here, unknown signals can be investigated in greater depth.


Our radio direction finding service works with networked SDRs and is based on the principle of time difference of arrival (TDoA). Eleven trained staff members ensure operation 24/7.

The way we work

Detection of emissions

Our software-based broadband scanner covers all amateur radio bands and scans them in real time for non-amateur radio signals. We also receive reports from the amateur radio community, which we also evaluate.


The next step is classification. Here, the signals are examined more closely to determine the exact parameters of the emissions.

Direction finding

In order to be able to assign an unknown signal to an originator, radio direction finding is necessary. our radio direction team is able is able to determine a position via networked SDR 24/7.

ITU Appendix 10

If all parameters are known and if it's a genuine intruder, a report is sent to the German PTT. The PTT checks the report and sends a complaint (Appendix 10) to the country of origin based on an international agreement.


Our shortwave listening station is fully automated and monitors the amateur radion bands 24/7 for unauthorised emissions to be received in central Europe.

Learn all about our system in this article.

System status

and IT

Server, SDRs, antenna switch

monitoring station

Scan mode on 60, 40, 17, 20, 15 and 10 m HF

radio direction finding

System up.
Team available.


DARC e.V.                     
Lindenallee 4
43225 Baunatal


via Form              

+49561 949880