Applied Concepts, Inc., formed in 1977, introduced the first Stalker radar to the law enforcement industry in 1990. Because of the technology introduced by the Stalker product line, the entire police radar industry has been transformed from a complacent “me too” industry to a very dynamic “state-of-the-art” industry with all competitors trying to play “catch up” with the Stalker products.

Stalker Radar has become the dominant Doppler radar system and continues to lead the industry in technology breakthroughs and product innovations. Stalker team members were involved in almost every significant radar-based product development since 1970 including:

• The first solid state police radar
• The first moving traffic radar
• The first K-Band radar
• The first K-Band handheld radar
• The first microprocessor radar
• The first Ka-Band radar
• The first cordless radar
• The first DSP radar
• The first “long range” radar
• The first digital antenna radar
• The first radar simultaneously tracking strong and faster targets
• The first direction sensing moving radar
• The first radar with Automatic VSS Calibration
• The first radar with Automatic VSS stationary mode / moving mode switching
• The first radar that simultaneously monitors 2 moving zones or 4 stationary zones
• The first radar with Rear Traffic Alert

Direction Sensing Technology

Doppler Radar works by transmitting a signal at a known frequency, and when that signal is reflected off moving objects, its frequency is shifted. Doppler radar systems measure the “absolute” change in frequency, often referred to as the “Doppler frequency.” The Doppler frequency is the same for objects approaching or going away. The Stalker DSR takes an ingenious (and patented) approach to measuring the Doppler frequency. Each antenna has two sets of microwave circuits and two sets of amplification / digitizing circuits. The two microwave circuits are designed to provide two simultaneous Doppler signals with a 90-degree phase difference depending on direction. The digitized Doppler information is sent to the Digital Signal Processor, which performs a Complex Fast Fourier Transform computation to obtain relative direction for each target.