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AWR2944: Using an automotive radar as a space debris detector

Pål Ellingsen
Prodigy 10 points
Part Number: AWR2944


Dear whom it may concern.

We are planing on placing a automotive radar in space to try and detect small pieces of space debris. This radar would be part of a student satellite being built by our university. The objects are between 1-10 mm, and we want to detect them up to 500 m away. Some back of the envelope calculations based on the AWR2944 tells us that this should be possible by modifying the parameters in the radar.

I'll phrase my questions for the AWR2944, but let me know if any other device you have is better suited

  • Orbital velocities are a lot higher than car velocities, meaning that we need to see objects at 16 km/s, which corresponds to a Doppler shift of up to 7 MHz. Will the device be able to detect this? From the specifications it looks like the bandwidth is 15 MHz
  • We would like to test the device on ground, without having to go to a laboratory cappble of providing 16 km/s objects (if any exist). Is it possible to simulate the Doppler shift on the antenna side? One option is an external down converter, mixer and up converter.
  • Would you be interested in working closely with us on trying to get the device in orbit?

Kind regards

Pål Ellingsen

  • 0
    TI__Guru**** 150474 points

    Hi,

    I don't think the AWR2944 would be able to detect objects of 1-10mm beyond a few meters.

    Thank you

    Cesar

  • 0 in reply to Cesar
    Prodigy 10 points

    Back of the envelope calculations says it will, when modifying the pulse pattern accordingly. Anyway that was not the question.

  • 0 in reply to Pål Ellingsen
    TI__Guru**** 150474 points

    Hi,

    I will ask the Systems Design team to review your questions

    thank you
    Cesar

  • 0
    TI__Prodigy 545 points

    Pal,

    The final IF frequency depends both on the FMCW parameters and the Doppler shift.   If you use a nonzero slope S (Hz/s), then the IF frequency would be 2*d*S/c +/- f_d, where d is the distance in m, c is the speed of light, and f_d is the Doppler shift (the +/- depends on the sign of S and whether the object is approaching or moving away from the radar).

    As long as the absolute value of the final IF frequency (from both the distance and Doppler) is within 15MHz, AWR2944 would be able to digitize it.  For 500m detection, you would need to use a very low slope, and that is possible on the device.

    Also, to test this, your recommended approach works well, except you don't need the extra mixer. You can just downconvert and upconvert using two separate signal sources that are offset by 7MHz.  This is what is commonly used to emulate Doppler in radar target simulators.

    Going back to Cesar's point, however, I question the ability to detect an object at 500m away that is 1-10mm in diameter.  Do you know what is the RCS of these small space debris?  Are these typically metallic?  Have you plugged in the operating parameters to the standard radar range equation?

    Regards,

    Brian

  • 0 in reply to bginzz
    Prodigy 10 points

    Thank you for the answer, I did not fully understand the test setup, but it might become clearer when we start working with this.

    The objects are metallic, and the standard radar range equation says that with a antenna gain of 43 dB and 1 W of power, we will be able to detect the objects. Though if we really want that high of a gain will depend on the measurement volume we are interested in. It might be that a wider, shorter ranged beam is better.

  • 0 in reply to Pål Ellingsen
    TI__Prodigy 545 points

    Pal, yes a high gain antenna will help.  I just want to double check on the power.  AWR2944 has a typical output power per transmitter of 12dBm per antenna, substantially less than 1W (30dBm).

  • 0 in reply to bginzz
    Prodigy 10 points

    Thank you for the double check, I agree that most likely we will need to implement a high gain antenna.

  • 0 in reply to Pål Ellingsen
    TI__Guru**** 150474 points

    Thank you

    Cesar