SEN0395 Triggers movement before observed region the sensor?

Sensor:

mmWave - Human Presence Detection Sensor (9 Meters)

SKU : SEN0395
https://wiki.dfrobot.com/mmWave_Radar_Human_Presence_Detection_SKU_SEN0395

Situation and set up:

Imagine the sensor is fixed mounted and 

NOT exposed to extreme conditions, such as 
high/low temperatures, 
(direct) solar radiation, 
vibrations, 
swirling dust, 
etc.

and 

via 
   "sensor.DetRangeCfg(20, 30);"
set to observe the region 
from around (20 x 0.15 =) 3.0 meter 
up to around (30 x 0.15 =) 4.5 meter.

 

My questions:

My question is whether the sensor will trigger on movement at a distance of about 1.5 meters.
(Assume that movement at around 1.5 meters will not block the sensors' view beyond 1.5 meters.)