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IWR1843BOOST: Ghost target generated when an object is in motion

CheeseCat Yellow
Prodigy 20 points

Part Number: IWR1843BOOST
Other Parts Discussed in Thread: IWR6843AOP

Hello.

I am currently conducting radar research using TI's IWR1843BOOST and DCA1000 board.

I have linked the video address of the project I am working on.

https://www.youtube.com/watch?v=e8qVHahZYEQ 

I will provide a brief description of the video.

I have installed the radar at a height of approximately 1.6 meters.

In the office, a person is moving.

The system displays information about the person's movement and detects stationary objects.

At the bottom left of the video, real-time range-doppler map information is displayed.

The range-doppler map is presented in a clutter-removed form. (dB scale)

I have a question.

I'm curious about why ghost signals tend to occur at longer distances when a person is in motion. (range-doppler map)

I observed a similar phenomenon when running the demo using only IWR1843BOOST without using DCA1000.

  • 0
    TI__Mastermind 38575 points

    Hi,

    You see ghost targets because of the multi-path reflections from a moving object in a cluttered environment. When a person moves, the radar reflections bounce off them, onto other surfaces and return back to the radar.

    Best,

    Nate

  • 0 in reply to Nathan Block
    Prodigy 20 points
    1. I'm curious if other users have had similar experiences testing indoors using the TI mmWave EVB.
    2. I'm conducting signal processing tasks such as range-FFT, Doppler-FFT, CFAR, and AoA. Are there other signal processing techniques that can eliminate ghost targets? For example, using Capon beamforming with range-azimuth map.
    3. Watching this video at https://www.youtube.com/watch?v=iBIfSnqENT0, it seems there may be similar phenomena to what I'm experiencing.
    4. If I use the IWR6843AOP and install it on the ceiling, would it be better?
  • 0 in reply to CheeseCat Yellow
    TI__Mastermind 38575 points
    CheeseCat Yellow said:
    • I'm curious if other users have had similar experiences testing indoors using the TI mmWave EVB.

    Yes, this is common. You can reduce them by increasing the CFAR detection threshold or decreasing the output power from the device.

    CheeseCat Yellow said:
    • I'm conducting signal processing tasks such as range-FFT, Doppler-FFT, CFAR, and AoA. Are there other signal processing techniques that can eliminate ghost targets? For example, using Capon beamforming with range-azimuth map.

    I don't have a reason for why the Capon beamforming would decrease ghost targets, but it may.

    CheeseCat Yellow said:

    This looks like ghosting to me.

    CheeseCat Yellow said:
    If I use the IWR6843AOP and install it on the ceiling, would it be better?

    It may be better, but it's not guaranteed. Ghosting is somewhat scene-dependent, so performance may be better with a ceiling mount in some scenes, and better with a wall mount with others.

    If you're worried about too many ghost points in your output. I would increase the CFAR threshold to detect fewer points.

    Best,

    Nate