More KerberosSDR Passive Radar Demos

KerberosSDR is our upcoming low cost 4-tuner coherent RTL-SDR. With four antenna inputs it can be used as a standard array of four individual RTL-SDRs, or in coherent applications such as direction finding, passive radar and beam forming. More information can be found on the KerberosSDR main postPlease remember to sign up to our KerberosSDR mailing list on the main post or at the end of this post, as subscribers will receive a discount coupon valid for the first 100 pre-order sales. The list also helps us determine interest levels and how many units to produce.

In this post we're showing some more passive radar demos. The first video is a time lapse of aircraft coming in to land at a nearby airport. The setup consists of two DVB-T Yagi antennas, with KerberosSDR tuned to a DVB-T signal at 584 MHz. The reference antenna points towards a TV tower to the west, and the surveillance antenna points south. Two highlighted lines indicate roughly where reflections can be seen from within the beam width (not taking into account blockages from mountains, trees etc).

The second video shows a short time lapse of a circling helicopter captured by the passive radar. The helicopter did not show up on ADS-B. On the left are reflections from cars and in the middle you can see the helicopter's reflection moving around.

We are expecting to receive the final prototype of KerberosSDR within the next few weeks. If all is well we may begin taking pre-orders shortly after confirming the prototype.

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Could you please release some specifications for the KerberosSDR and how the desig works?
Many thanks!


Helicoptors don’t require ADSB equipage, unless flying IFR or transponder mandatory zones. Many rotary wing aircraft do like SAR, Police or military are fully IFR equipped.
There are different antenna types used for direction finding
– Directional antennas are used for mobile and/or fixed station
– Doppler antenna basis e.g. for VHF/UF-COM using, with one receiver on the antennas switched rotating on the antenna basis and the sen´cond reference reciver in the middle connected to the 2 receiver
– ADF in aircraft up to 2000 kHz, using NDB and BC stauions is a bit different again


If we use it in / on a carfor Passive radar say, using a local fm radio signal. Can the 4 antennas be omni-directional antennas or will they still need to be Directional yagi’s.


On a boat at sea. I could put 4 omni-directional antennas at EXACT KNOWN positions.

One at front.
One at back
One on left side.
One on right.

Mathematically it would appear possible to hear the source signal say a TV or radio signal on all 4 antennas at minutely different time due to the antennas being at different distances from the source signal.

It should also be possible to hear the known signals reflections from say another metal ship at sea at different time on all four antennas.

Can the KerberosSDR software and Hardware calculate this as a passive radar equation and plot the detected ships position?


Super excited for something SDR based to hit the market with RDF capability. Hopefully you’ll have GPS functioning with it.

You’re going to make me drill another 4 holes into my car lol.