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RFbeam Microwave GmbH | Schuppisstrasse 7 | CH-9016 St. Gallen | www.rfbeam.ch | K-LD2 | data sheet

09/2018 - Revision B | Page 9/20

Detection algorithm

The detection algorithm uses the following steps:

1. Scan the FFT spectrum for peaks with a magni-

tude higher than the set threshold level and with

the direction to detect set with the parameter D03.

2. Check if the peak is a valid movement with

the correct direction or if it is an interference.

3. Increase the immunity against interferences by

checking if the movement is constant (see parame-

ter Immunity D02).

4. If there is a valid detection, estimate the speed

bin and magnitude.

5. Latch all the information to the detection

register (see parameters R00, R01 & R02)

and to the digital outputs.

6. Decrease the hold time if there is no valid detection.

7. Reset the hold time if there is another

valid detection.

8. Reset the detection register and the digital outputs

if the hold time has elapsed.

You can find more advanced configurati-

on options for  the detection algorithm in

the chapters Speed limitation and ranging,

FFT filter and Adjust hold time and sensitivity.

Reaction Time

The reaction time of the sensor depends on different

settings and can be calculated with the equation below

when the FFT average feature is disabled.

With the FFT average feature enabled (see parameter

S0A) the equation changes to:

t

· (Immunity + 1)

N

FFT

ƒ

Sample

256

ƒ

Sample

t

· (Immunity + 1) · 2

N

FFT

ƒ

Sample

256

ƒ

Sample