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How to detect flying or orbiting objects with SDR technology and

the GRAVES radar

How it works :

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From : http://www.qsl.net/g0isw/g0iswradioastronomy.htm

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Our setup :

The station was created at the end of 2013 with the aim of identifying and cataloging the meteor passing in our area and joins the already earlier VLF station for detecting SID (Sudden Ionospheric Disturbance) .

Using Doppler effect of objects passing through the signal of Graves radar transmitting pure carrier at 143.050 MHz and captured in Turin with a simple receiver Icom ICR 1500 in CW with a discone antenna .

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All is connected to a 16 bit soundcard and a server that stream online data each minute : http://www.sidmonitor.net/gallery/station2.html

The software used is Spectrum Lab : http://www.qsl.net/dl4yhf/spectra1.html

To obtain more accurate data and a more direct correlation of events, with time, we added to the main spectrum ,two graphs: The first one is related directly to the spectrogram of the main radar reflection, while the second, with the same flow time of the others, in the VLF frequency range of 3-khz to 30 kHz, monitoring directly all SID station like NAA,HWU, NSY and others.

First Plot to main spectrum

VLF Mirror

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The main purpose is to be able to detect the correspondence between the passage of meteors or atmospheric phenomena in the VHF ,in the optical and even in the VLF. We then added in order to have a relationship in the field of optics a Moonglow All Sky

Camera that should allow a panoramic view of the sky from the station itself.

As we can clearly see many traces of planes that reflect their Doppler signal on the main spectrum, we added the free FlightRadar useful application that allows you to see live aircraft tracked in our area.

And a real time map of lighting strikes over Europe , courtesy of www.Blitzortung.org

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Meteors,airplanes,satellites and others troposhperic phenomena captured

Big unknown(probably military) satellite trace on the right , many meteors , airplane trace on the left anf

tropospheric signal on all the spectrogram

On the left airplane landing , some other on transit on all the screen , meteors , tropospheric signal and perhaps a

tropospheric duct ?

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On the left the doppler echo of the ISS – Due to the large doppler shift we have used a Perseus receiver connected to

an IF output of the ICR1500 at 10.7 MHz . Vertical and horizontal axes are reversed respect to the previous spectra.

On the center clearly visible the tropospheric signal and Doppler echo from airplanes .

Gallery of quick events post processed :

Meteor shower

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Meteor with induced meteor Scatter

Meteor and long meteor scatter

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Little meteor and big meteor scatter

Unknown and phenomena a meteor before . The tropospheric signal is always present and quite steady .

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Some experiments was made also wit the FunCubeDongle and with low cost USB keys , with heavy RF bandpass

filtering after the antenna.The performance was lower , but the experience still possible in some way .

SDR Low cost RTL consumer USB key

FunCube Dongle PRO