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IWR1642BOOST: Does physical measurements of room matches with the sensor data?

Ha An
Prodigy 180 points
Part Number: IWR1642BOOST
Other Parts Discussed in Thread: IWR1642

Hi all,

I am currently working in iwr1642 people counting demo application. I just want to know few details like ,

1. Does the posX and posY values from the sensor matches exactly the physical measurements of the target from the sensor.?

       For example, the sensor is placed parallel to wall at 0 degrees with 15 degree tilt. A person standing at a distance of 3 meters directly away from the sensor . So the points we are getting will be (0,3)?? 

2. Does the height of sensor mount affects data points?

       Example: At a height of 2.5meters from the ground, say, a person standing at one point gives (1.0,2.0) . If i increase the height of the mount from 2.5 m to 4 meters, will the person standing at the same point be (1.0,2.0) always??

Thanks in advance,

Ha An

  • 0
    TI__Mastermind 28055 points

    Hi Ha An,

    Because the demo is working in 2-D, the X, Y coordinate will not perfectly match the actual truth. For example, assume the EVM is mounted 2.25 meters above the ground and tilted down 10 degrees.  There is a person standing in front of the device at position (0,3). Assume that the returned points come from the person at max height of 2 meters and minimum height of 1 meters. The radar will get a range and angle measurement for each detected point.  The highest point is 0.25 meters below the sensor, 3 meters in front of the sensor, and 0 meters to the left of the sensor. So the range measured is hypot(0.25, 3) = 3.01 meters.  The range to the lowest point is hypot(1.25, 3) = 3.25 meters.

    With 0 degree azimuth, the locations of these points are 3.01 and 3.25.  So we will place the target center at the mean of all detected points, roughly 3.125 meters. So the returned location of the target is (0, 3.125) instead of (0,3). In reality, the differences in distance measurement we see are usually less than 5 cm.  See our TI Design, where we test this exact case. See page 24 for this test.

    Regards,

    Justin