Nuisance Alarms

Nuisance alarms are caused by the radar detecting the movement of objects that are not of interest to the operator.  Such targets can include wind blown trees, bushes and grass as well as man-made objects such as sign posts, fences and other objects that can move in the wind, and even air-conditioning fans.  These wind blown objects are often characterised as having very low positive and negative velocities on consecutive scans without actually moving anywhere and often are small in Radar Cross Sectional (RCS) area.

There are a number of facilities available within the Blighter radar to help manage and reduce nuisance alarms.  Firstly, the allowable target size can be set within the radar.  Wind blown nuisance alarms are often small, so increasing the Blighter radar's minimum target detection size will help to ignore and therefore filter out these unwanted targets.  Additionally the minimum detection velocity of the Blighter radar can be fine tuned to ignore the very slow movement of the wind blown targets.  These changes may reduce the radar's ability to detect very small and slow targets such as crawling humans, but the operator will be presented with a clearer picture and the ability to detect the target once they start walking or are away from the wind blown vegetation.  In addition to these bulk radar settings, it is also possible for the User HMI (Human Machine Interface) to filter the Blighter radar targets based on target size and velocity, allowing user defined zones to adapt the sensitivity of the radar to nuisance alarms on an area by area basis.  For example this allows the user to desensitise the Blighter Radar and HMI system around groups of trees, preventing nuisance alarms on the wind blown trees but allowing full sensitivity operation elsewhere.