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.
What is SENTRY PROBE?
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
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
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
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.