Why is RADAR PC and its associated products new technology?

Low cost Doppler Illuminators have been available since the mid 1970s. The reason why these devices have not found their way into low cost consumer products other than automatic door openers is that velocity processing requires significant computerized signal processing. Low cost Personal Computers of the past just did not have the speed and high resolution interfaces of current Personal Computers. Using sophisticated Super-Computer Algorithms, RADAR PC allows a low cost, off-the-shelf PC to do many things with RADAR that only high cost Military and Government systems exhibit.

RADAR PC uses the power of Digital Signal Processing (DSP) to digitally amplify the effective range of the Doppler Illuminator. This new feature (velocity amplification by signal processing) has greatly increased the value of low cost Doppler Illuminators. If the Illuminator is placed in a suitable reflector, this range may be multiplied many times at the sacrifice of horizontal coverage.

Can multiple Illuminators be used by one Computer and one incarnation of RADAR PC?

Yes, the signals are audio in nature and may be easily added together with an inexpensive audio mixer or switched by a simple audio switch.

Why is RADAR PC and its associated products unlike other RADAR systems?

SENTRY PROBE, RADAR PC, RADAR PDA, RADAR MAC, and RADAR NET use low power and low cost RADAR devices. RADAR PC, unlike other high-power, high-cost RADAR systems, is for application to short distances. High power RADAR is for detecting movement of objects at great distances, objects like Aircraft and Ships or Marine Navigation. These high power systems cost many thousands to a few hundred thousand dollars and are primarily for determining distance and position; velocity is a given. Then there are those weather RADARs which are not even practical for portability because they are as big as a house. RADAR PC uses similar devices that Police RADAR and RADAR guns use for distances of an arm's length to a few thousand feet. The cost of RADAR PC is less than one thousand dollars depending on the Illuminator chosen. SENTRY PROBE is less than one hundred dollars.

What is RADAR PC?

RADAR PC is software that operates on a Microsoft Windows based computer along with a Doppler Radar device connected to the computer's audio input providing a tool for detecting movement within distances of arm's length to a few thousand feet.


SENTRY PROBE is a stand-alone device not requiring a computer that uses any number of Doppler Radar devices to detect movement through most doors and walls. This detection is reported as a sound signal that allows the user to instantly know if any movement occurs in the illumination field of the Illuminator. This movement may be detected through most walls and doors.

What is RADAR NET?

RADAR NET allows RADAR PC to monitor movement over the Internet. The Internet Protocol (IP) that RADAR NET uses allows RADAR PC to remotely connect with a computer running RADAR NET. This allows the user to detect and display movement over the Internet.

What is a Doppler Illuminator?

Doppler Illuminators come in a wide variety of devices. This technology has evolved in a relative vacuum from public view. Named after Christian J. Doppler, Doppler is the change in frequency detected from the movement of a source of coherent radiation (light and radio) or sound. In this case, the Doppler RADAR energy is that frequency shifted energy received by a detector retroreflected by a moving object illuminated by a coherent microwave source on axis with the detector. This reflected energy is the product of the movement, the carrier frequency of the Illuminator, and the speed of light. Because the frequency of the illuminator is known, the velocity of the reflected object can be detected and displayed based on the constant of the speed of light. Doppler Illuminators may be Gunnplexors, Dielectric Resonant Oscillators, Composite amplifiers, circulators and magnetrons, or even Traveling-Wave Tube amplifiers and Klystrons. Their operating frequencies may be as low as 200 Mega Hertz (MHz) with an antennae a mile long and an output power of one million watts (NAVSPASUR), or as high as 300 Giga Hertz (Ghz) the size of a raisin. The typical operating frequencies occur in several bands reserved for Armature band operation not requiring a type approval from the FCC. These frequencies are:

239 - 245 MHz
420 - 450 MHz
902 - 928 MHz
1.24 -1.2 GHz
2.39 - 2.45 GHz
3.3 - 3.5 GHz
5.65 - 5.925 GHz
10 - 10.5 GHz
24 - 24.25 GHz
33.4 - 36 GHz
47 - 47.2 GHz
75.5 - 81 GHz
142 - 149 GHz
241 - 250 GHz

The typical low cost Illuminators occupy three bands - 10.5, 24, and 35.5 GHz

Why are these 3 frequencies used most often?

These frequencies are in bands allocated by the FCC as Armature Bands. Electromagnetic radiation of a limited power level at these frequencies may be transmitted without a type approval. Type approval requires significant fees and certification costs which raises the cost of the Illuminator and must be passed along to the purchaser. RADAR PC and its associated products use low cost armature band devices.

Why would these devices be chosen for this application?

These devices have found their way into Police and Sports RADAR and automatic door openers. Because they are mass produced and have been so for so many years, they are readily available at low cost.

These devices are also used because of their frequencies of operation and physical size. The lower the frequency the better the microwaves penetrates solid objects and are less sensitive to precipitation but are larger and may require a dish for long distances. The higher frequency devices are smaller, give better speed resolution and do not require a large dish but do not penetrate solid objects very well, are higher in cost and are more sensitive to precipitation effects.

What is Across-the-Road Angle?

The angle which departs from straight Down-the-Road. Logically, the illuminator is not placed in the street so that the angle of incidence is zero to the motion of the target subject. Therefore, the illuminator is placed at some angle from the direction of the motion of the target subject. If the angle nears 90 Degrees, the motion is Zero. 90 degree motion detection is not allowed or possible. The closer the illuminator is to the axis of motion of the target subject, the less the relative velocity must be corrected. The advantage of using RADAR PC is the ability to accurately display and record-to-disk, velocity such as automobile speed from any angle, known as Across-the-Road, rather than directly Down-the-Road to the flow of traffic.