Radar stands for “radio detection and ranging.” Applications range from aviation to weather to physical security, where adoption is on the increase. This note provides a comprehensive view on security radar.
Radar stands for “radio detection and ranging.” Applications range from aviation to weather to physical security, where adoption is on the increase. This note provides a comprehensive view of the technology.
What is radar and its advantages
Radar was first invented in the 1940s. The technology shoots a signal to an object and processes the bounced-back signal to determine the distance and velocity of the object. In comparison to other security systems, radar technology has certain advantages, which are summarized as follows.
Versus thermal imaging
Radar compensates for the shortcomings in thermal imaging. “Thermal imaging relies on heat measurements; therefore intruders can be masked by walking near to walls or stone structures that retain heat,” said Mark Rainbow, Business Development Manager for UK and Export at
360 Vision Technology. “Thermal imaging systems only measure temperature, not distance to the object being measured, and can therefore suffer from false alarms.”
Versus video surveillance
Unlike
video surveillance, radar entails the transmitting and receiving of radar signals. “Monitoring a specified area can be achieved by transmitting radio waves and detecting the waves that bounce off objects in the field of detection with a receiver. This allows the radar device to detect motion regardless of the light conditions. This is something most visual cameras would struggle with,” said Martina Lundh, Global Product Manager for Radar Products at
Axis Communications.
Versus motion sensors
Radar offers advantages over passive infrared-based motion sensors as well. “In intrusion detection, radar is definitely a good choice. It reacts very sensitively on motion, and advanced sensors deliver range and angle information as well so false alarms triggered by bushes in the wind or objects outside the area of interest can be neglected,” said Eva Maria Buchkremer, Head of Product Management at
InnoSenT.
What applications is radar suitable for
Radar is an effective situational awareness tool independent of light or weather conditions. Applications vary. Below are some of the applications radar is suitable for.
Wide open space
Radar’s resilience to external factors makes it ideal for surveillance of wide-open outdoor areas. “Radar works best in large open spaces and is often chosen because of its range capabilities, its accuracy and alarm functionality. 360 security applications include airports, ports, prisons, VIP properties, car compounds, water treatment works and solar farms, to name a few,” Rainbow said.
Velocity/distance detection
Radar is a good speed detection system. End users with speed detection needs can benefit from radar devices.
“For safety reasons, the speed limit around school areas or residential areas is quite often lower than anywhere else. A radar is an accurate speed detector that can notify drivers of whether they should slow down. In this context, the radar can easily trigger a strobe siren or a radar speed sign to make drivers aware when they are exceeding the speed limit,” Lundh said.
Personal safety
According to Lundh, radar is also a great solution for personal health and safety. “Many sites such as outdoor swimming pools and building sites are closed at night, when access is prohibited due to the high risk of injury. In some cases, the end-customer is liable if an accident happens. When the radar is used to monitor and protect fenced areas, trespassers are automatically detected and an alarm is generated,” she said.
How to choose the right radar solution
This also depends on application and site conditions. According to Rainbow, a high operating frequency reduces the effect of interference from other wireless systems. He further mentions ease of installation and setup as well as the following features:
- Integrated software
- GPS for downloading a map
- Setup of high priority, low priority, and exclusion zones
- Multiple objects tracking
- Sensitivity filtering to determine the size and speed of object to be detected
- Clutter filtering to remove reflections from unwanted static and moving objects from the target zones
- Camera tilt and zoom setting over multiple ranges
- Alarm outputs
- Time schedule
- Installation
How security radar should be installed
When installing a radar security system, several things should be taken into consideration. These include the surface and height of installation and the line of sight of the area.
“Radar sensors need a clear line of sight to be able to detect properly. In most cases, it is beneficial to choose an installation height so the sensor looks slightly inclined from above. It is recommended that the end user tests whether the area of interest is covered by walking into it from different angles when the sensor is installed,” Buchkremer said.
“Installation should be on a flat surface overlooking relatively flat terrain. The radar is a line-of-sight device and cannot see through buildings or trees. Installation height should be between 3 and 4 meters,” Rainbow said.