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RFbeam Microwave GmbH | Schuppisstrasse 7 | CH-9016 St. Gallen | www.rfbeam.ch | K-MD2 Engineering Sample | data sheet

07/2018 – Revision A | Page 11/23

Tracking

With a set of parameters the number of tracked

targets can be influenced. On each frame the range,

speed and direction of every track is updated. An al-

pha-beta-gamma tracker is used, whereby the speed

is updated with the current acceleration estimate, and

the range is updated with the current speed estimate.

Track Life (PSBL, PSTL)

The list of detected peaks is compared with the

updated list of known tracks. If a peak matches an

existing track, it is marked as associated and the life

of the track is increased. If no peak is found for the

track, the life of the track is decreased. If there is no

existing track for the peak a new track is created.

Once the life of a track reaches a minimum threshold

it is reported as a confirmed track. The life of a track

is limited, in that it will be lost if no detections are as-

sociated with it for the maximum track life. Note that

the track will no longer be reported once the track life

reaches the minimum threshold.

Range and Speed Jitter (PSRJ, PSSJ)

Every new detected target is compared to the known

tracks. If the range and the speed of the new target

are within the jitter values around the track’s speed

and range the target is assigned to the track and the

track is updated.

Assume Constant Speed (PSCS)

When assuming constant speed is on, the tracking al-

gorithm allows only small changes in speed between

each measurement. This is useful when objects are

moving slowly or are moving towards or away from

the radar at high speed (e.g. looking along a road).

It can result in tracks being lost if the speed chan-

ges quickly.

When assuming constant speed is off, the tracking

algorithm allows large changes in speed. This is useful

when objects are moving across the field of view such

that their speed towards the radar changes rapidly as

they pass the radar (e.g. looking across a road). It can

result in tracks being split if the speed information

is noisy.

Direction Threshold

The ‘

direction_error_threshold’ is used

when comparing new detections to existing tracks.

The track will follow the detection that most closely

matches the predicted range, speed and direction of

the track. If all of the detections have a difference in

direction greater than the ‘

direction_error_th-

reshold’, the strongest detection with a matching

range and speed is used.

The value should be set to zero if no multiple object

with a similar range and speed are expected, so

the strongest signal (within the jitter thresholds) is

always tracked.

If multiple objects with the same range and speed are

expected (e.g. when looking along a multi-lane road)

the value can be:

– set small (e.g. 5 degrees) so that the direction is

only used if it matches the track reasonably well,

otherwise the strongest signal is used; or

– set high (e.g. 45 degrees) so that the detection with

the closest match in direction is always used (even

if there is a big difference).

Using smaller values can result in tracks

being merged. Using larger values can result

in tracks being split.