U.S. patent application number 12/916008 was filed with the patent office on 2011-05-05 for standoff range sense through obstruction radar system.
This patent application is currently assigned to VAWD APPLIED SCIENCE AND TECHNOLOGY CORPORATION. Invention is credited to Robert Adams, Vinh N. Adams, Wesley H. Dwelly.
Application Number | 20110102234 12/916008 |
Document ID | / |
Family ID | 43924834 |
Filed Date | 2011-05-05 |
United States Patent
Application |
20110102234 |
Kind Code |
A1 |
Adams; Vinh N. ; et
al. |
May 5, 2011 |
STANDOFF RANGE SENSE THROUGH OBSTRUCTION RADAR SYSTEM
Abstract
A standoff range, sense-through-obstruction radar system is
capable of detecting micro-Doppler, or life form signatures, and
movements through obstructions at stand-off ranges and displaying
the target information over a live video feed of the area under
surveillance. The sense-through-obstruction radar system comprises
an antenna assembly that includes a horn antenna and a reflector
configured to reflect radio frequency (RF) energy to/from the horn
antenna. An antenna pointing assembly supports the antenna
assembly. The antenna pointing assembly is configured to move the
antenna assembly to point the antenna assembly toward an
obstruction. A sensor assembly is mounted to the antenna assembly
so that the sensor assembly is aligned with the RF beam formed from
the RF energy reflected from the reflector to the horn antenna. The
sensor assembly is configured to detect the location of the
obstruction and to provide information to assist pointing of the
antenna assembly toward the obstruction.
Inventors: |
Adams; Vinh N.; (Tucson,
AZ) ; Adams; Robert; (Tucson, AZ) ; Dwelly;
Wesley H.; (Sahuarita, AZ) |
Assignee: |
VAWD APPLIED SCIENCE AND TECHNOLOGY
CORPORATION
Tucson
AZ
|
Family ID: |
43924834 |
Appl. No.: |
12/916008 |
Filed: |
October 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61257469 |
Nov 3, 2009 |
|
|
|
Current U.S.
Class: |
342/22 ;
342/52 |
Current CPC
Class: |
G01S 13/582 20130101;
G01S 13/888 20130101; G01S 13/522 20130101; G01S 13/867 20130101;
H01Q 19/132 20130101; G01S 13/865 20130101; G01S 7/04 20130101;
H01Q 1/125 20130101 |
Class at
Publication: |
342/22 ;
342/52 |
International
Class: |
G01S 13/00 20060101
G01S013/00 |
Claims
1. A sense-through-obstruction radar system comprising: an antenna
assembly including a reflector and a horn antenna, the reflector
configured to reflect RF energy to the horn antenna; an antenna
pointing assembly supporting the antenna assembly, the antenna
pointing assembly configured to move the antenna assembly to point
the antenna assembly toward an obstruction; and a sensor assembly
mounted to the antenna assembly so that the sensor assembly is
aligned with an RF beam formed from the RF energy reflected from
the reflector to the horn antenna, the sensor assembly configured
to detect the location of the obstruction to direct pointing of the
antenna assembly toward the obstruction by the antenna pointing
assembly.
2. The sense-through-obstruction radar system as recited in claim
1, further comprising a radar computing device configured to direct
movement of the antenna assembly by the antenna pointing assembly
responsive to detection of the location of the obstruction by the
sensor assembly.
3. The sense-through-obstruction radar system as recited in claim
2, wherein the sensor assembly comprises a camera, the camera
configured to capture an image of the obstruction.
4. The sense-through-obstruction radar system as recited in claim
3, wherein the camera comprises an electro-optical camera
configured to capture at least one of a photographic image or video
of the obstruction.
5. The standoff range, sense-through-obstruction radar system as
recited in claim 2, wherein the camera comprises an infrared camera
configured to capture an infrared image of the obstruction.
6. The sense-through-obstruction radar system as recited in claim
5, wherein the sensor assembly comprises a range finder, the range
finder configured to detect a range from the antenna assembly to
the obstruction.
7. The sense-through-obstruction radar system as recited in claim
6, wherein the camera and the range finder are mounted to the
antenna assembly adjacent to the horn antenna.
8. The sense-through-obstruction radar system as recited in claim
7, wherein the antenna assembly further comprises at least one
support arm configured to support the reflector and the horn
antenna in an offset feed arrangement so that the horn antenna is
positioned to receive RF energy reflected from the reflector, the
support arm supporting the camera and range finder.
9. The sense-through-obstruction radar system as recited in claim
2, wherein the radar director assembly comprises a range finder,
the range finder configured to detect a range from the antenna
assembly to the obstruction.
10. The sense-through-obstruction radar system as recited in claim
2, wherein the antenna pointing assembly comprises a gimbal
configured to control the azimuth and elevation of the antenna
assembly.
11. A method for operating a sense-through-obstruction radar
system, comprising: transmitting range information to a radar
computing device, the radar computing device operable to utilize
the range information to configure a timing of a transmit-receive
cycle associated with the sense-through-obstruction radar system;
receiving track data corresponding to a filtered range/range-rate
pair from the radar computing device; and causing at least one
track box to be superimposed over a real-time image that represents
a field of view of the sense-through-obstruction radar system, the
at least one track box corresponding to the track data and
representing a target detected by the sense-through-obstruction
radar system.
12. The method as recited in claim 11, wherein the causing at least
one track box to be superimposed over a real-time image comprises
causing at least one track box to have a first hue when the target
is stationary and a second hue when the target is in motion.
13. The method as recited in claim 11, wherein the causing at least
one track box to be superimposed over a real-time image comprises
causing at least one track box to be represented as a human
avatar.
14. The method as recited in claim 13, wherein the causing at least
one track box to be superimposed over a real-time image further
comprises causing at least one track box to be represented as a
three-dimensional human avatar.
15. The method as recited in claim 12, wherein the first hue
comprises red and the second hue comprises green.
16. A sense-through-obstruction radar system comprising: a radar
operable to furnish sense-through-obstruction target detection; a
mobile computing device communicatively coupled to the radar, the
mobile computing device further including: a display device; a
memory operable to store one or more modules; and a processing
system operable to execute the one or more modules to: transmit
range information to a radar computing device that is operable to
utilize the range information to configure a timing of a
transmit-receive cycle associated with the
sense-through-obstruction radar system; receive track data
corresponding to a filtered range/range-rate pair from the radar
computing device; and cause at least one track box to be
superimposed over a real-time image displayed by the display
device, the real-time image representing a field of view of the
radar, the at least one track box corresponding to the track data
and representing a target detected by the radar.
17. The sense-through-obstruction radar system as recited in claim
16, further comprising a display module operable to cause the at
least one track box to have a first hue when the target is
stationary and to have a second hue when the target is in
motion.
18. The sense-through-obstruction radar system as recited in claim
16, wherein the module is configured to cause the at least one
track box to be represented as a human avatar.
19. The sense-through-obstruction radar system as recited in claim
18, wherein the module is further configured to cause the at least
one track box to be represented as a three-dimensional human
avatar.
20. The sense-through-obstruction radar system as recited in claim
16, wherein the first hue comprises red and the second hue
comprises green.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit under 35 U.S.C.
.sctn.119(e), of U.S. Provisional Application Ser. No. 61/257,469,
filed Nov. 2, 2009, which is herein incorporated by reference in
its entirety.
BACKGROUND
[0002] Sense through obstruction radar systems allow users to gain
actionable intelligence through obstructions such as building
walls, walls, fences, and foliage. These radars may be used by the
military, police, security, and firemen to provide a capability of
detecting, locating, identifying, and classifying moving and
stationary humans for rescue and clearing operations. Sense through
obstruction radars include a transmitter that transmits
electromagnetic waves that are reflected by objects and are then
detected by the radar's receiver. The transmitted waves interact
with objects that change the properties of the returned waves. When
an object is moving at a constant velocity, the returned wave is
shifted in frequency, which is called the Doppler Effect. The
larger the velocity, the larger the frequency shift. When the
object is moving towards the radar the frequency of the returned
wave is increased. Conversely, when the object is moving away from
the radar, the frequency of the returned wave is decreased. When
the target is not moving but is vibrating the returned signal
exhibits frequency sidebands called micro-Doppler. Because
electromagnetic waves travel roughly at the speed of light, the
round trip time from the radar to the target provides information
on the range of the target. Depending on the material, some portion
of the electromagnetic waves penetrates through obstructions such
as walls, but the amplitude of the waves is attenuated. For a given
material, the lower the frequency of the wave, the less attenuation
electromagnetic wave exhibits. As the frequency of the
electromagnetic waves decreases, the difficulty of measuring
micro-Doppler from human or animal life forms increases. Radars
usually operate in the frequency range of 300 MHz to 8 GHz to use
the properties of electromagnetic waves that can penetrate through
obstructions, while measuring Doppler and micro-Doppler effects of
human or animal life-forms. However, detecting a human or animal
life-form behind an obstruction is difficult because the
transmitted and reflected waves are both attenuated by the
obstruction. This makes detecting the Doppler and micro-Doppler due
to the human or animal life-form difficult, especially in the
presence of noise that is inherent in a radar. Another difficulty
encountered when detecting slow moving and vibrating objects is
that the frequency shifts and the signals are extremely small,
making it difficult to detect these shifts in the presence of the
stationary objects in the radars field of view, especially in the
presence of noise.
SUMMARY
[0003] A standoff range, sense-through-obstruction radar system is
disclosed that is capable of detecting micro-Doppler, or life form
signatures, and movements through obstructions at stand-off ranges
and a method of displaying the target information over a live video
feed of the area under surveillance. In an implementation, the
sense-through-obstruction radar system comprises an antenna
assembly that includes a horn antenna and a reflector configured to
reflect radio frequency (RF) energy to/from the horn antenna. An
antenna pointing assembly supports the antenna assembly. The
antenna pointing assembly is configured to move the antenna
assembly to point the antenna assembly toward an obstruction. A
sensor assembly is mounted to the antenna assembly so that the
sensor assembly is aligned with the RF beam formed from the RF
energy reflected from the reflector to the horn antenna. The sensor
assembly (e.g., a range finder and an electro-optical camera) is
configured to detect the location of the obstruction and to provide
information to assist pointing of the antenna assembly toward the
obstruction by the antenna pointing assembly. The radar system may
include a radar computing device configured to direct movement of
the antenna assembly by the antenna pointing assembly in response
to the detection of the location of the obstruction by the sensor
assembly.
[0004] During operation of the sense-through-obstruction radar
system, range information is transmitted to the radar computing
device, which is operable to utilize the range information to
configure timing of transmit-receive cycles associated with the
sense-through-obstruction radar system. Track data corresponding to
a filtered range/range-rate pair is also received from the radar
computing device. At least one track box may be superimposed over a
real-time image that represents a field of view of the
sense-through-obstruction radar system. The track box corresponds
to the track data and represents a target detected by the
sense-through-obstruction radar system.
[0005] This Summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This Summary is not intended to identify
key features or essential features of the claimed subject matter,
nor is it intended to be used as an aid in determining the scope of
the claimed subject matter.
DRAWINGS
[0006] The detailed description is described with reference to the
accompanying figures. The use of the same reference numbers in
different instances in the description and the figures may indicate
similar or identical items.
[0007] FIG. 1 is a block diagram illustrating an example
implementation of a standoff range sense through obstruction radar
that is capable of detecting micro-Doppler, or life form
signatures, and movements through obstructions at stand-off ranges
and a method of displaying the target information over a live video
feed of the area under surveillance.
[0008] FIG. 2 is a flow chart illustrating an example setup
procedure for a sense through obstruction radar system shown in
FIG. 1.
[0009] FIG. 3 is a flow chart illustrating an example radar data
processing cycle for a sense through obstruction radar system shown
in FIG. 1.
[0010] FIG. 4 is a block diagram illustrating an example
implementation of the sense through obstruction radar shown in FIG.
1.
[0011] FIG. 5 is a perspective view depicting an example
implementation of the sense through obstruction radar system shown
in FIGS. 1 and 2, further illustrating the radar antenna, sensor
assembly and azimuth and elevation gimbal used for pointing the
antenna.
[0012] FIG. 6 is a diagrammatic pictorial representation
illustrating the alignment of the sensor assembly and the radars RF
beam for the sense through obstruction radar system shown in FIG.
1, wherein the sensor assembly is comprised of a range finder and
an electro-optical camera, and the alignment of the range finder
beam, the electro-optical cameras field of view (FOV), and the
radars RF beam is shown.
[0013] FIG. 7 is a flow chart illustrating an example radar data
processing cycle for the sense through obstruction radar system
shown in FIG. 1.
[0014] FIG. 8 is a diagrammatic pictorial representation
illustrating a graphical user interface (GUI) suitable to operate
the sense through obstruction radar system shown in FIG. 1.
DETAILED DESCRIPTION
Overview
[0015] Stand-off range sense through obstruction radars furnish
enhanced capability to detect moving and stationary micro-Doppler,
or life-form, signatures for rescue and clearing operations.
Typical obstructions include walls of buildings, foliage, and so
forth, but could be any type of obstruction except for solid metal
obstructions. Stand-off range sense through obstruction radars can
be used by the military, police, security, and firemen.
Additionally, the radars can provide standoff range human biometric
monitoring for medical personnel to help save lives (e.g.,
battlefield wounded). It is also desirable that these radars be
able to detect very low velocity motion and small motion (also
known as micro-Doppler), as exhibited by life-forms, in the
presence of all the stationary objects, or clutter, that are in the
radars field of view (FOV) and range of interest. It is also
desirable that these radars be capable of operating at stand-off
ranges greater than or equal to at least twenty (20) meters either
as a requirement of the application or to provide safety or stealth
to the operators. Functionally, to be useful to the military,
police, security, firemen, and medical personnel, it is desirable
that these radars be easy to setup, operate, and present the target
information in an easy to understand format to the operator.
[0016] Accordingly, a standoff range, sense-through-obstruction
radar system is disclosed that is capable of detecting
micro-Doppler, or life form signatures, and movements through
obstructions at stand-off ranges and a method of displaying the
target information over a live video feed of the area under
surveillance. In an implementation, the sense-through-obstruction
radar system comprises an antenna assembly that includes a horn
antenna and a reflector configured to reflect radio frequency (RF)
energy to/from the horn antenna. This horn and reflector pair
constitutes a high gain antenna assembly that provides sufficient
gain to enable the system to operate at stand-off ranges. The high
gain antenna is mounted to an antenna pointing assembly that is
configured to point the antenna assembly towards the obstruction of
interest. A sensor assembly, which may be comprised of an
electro-optical camera, a range finder, and so on, is mounted to
the antenna assembly so that the sensor assembly is aligned with
the RF beam formed from the RF energy from the horn antenna that is
reflected from the reflector. The sensor assembly is configured to
provide information to assist pointing of the antenna assembly
toward the obstruction by the antenna pointing assembly.
[0017] A radar computing device such as a computer, laptop
computer, tablet computer, and so on, is provided with a graphical
user interface (GUI) that is configured to simplify the setup and
operation of the sense through obstruction radar. The GUI provides
this functionality through the user interface elements tied to the
antenna pointing device, the outputs of the range finder and
electro-optical camera, and displays radar data in an easy to
understand format. During operation of the
sense-through-obstruction radar system, range information is
transmitted to the radar computing device, which can utilize the
range information to control the timing of transmit-receive cycles
associated with the sense-through-obstruction radar system to keep
the radar range of interest centered on a target of interest.
Additionally, track data corresponding to a filtered
range/range-rate pair associated with a target is also received
from the radar computing device. At least one track box may be
superimposed over a real-time image that contains the FOV of the
sense-through-obstruction radar system. This real-time image and
the track box are displayed in the GUI. The track box corresponds
to the track data and represents a target detected by the
sense-through-obstruction radar system.
Example Implementations
[0018] FIG. 1 illustrates an example implementation of a sense
through obstruction radar system 100. The system 100 is comprised
of a radar computing device 102 that is connected to a radar
assembly 104 through one or more communications cables 106. The
radar computing device 102 can be a computer, a laptop computer, a
tablet computer and so on that is comprised of at least a
processor, memory, a display device, and an input device. The
processor provides processing functionality and may execute one or
more software programs which implement techniques described herein
and may access the memory to store and retrieve data.
[0019] The memory is tangible computer-readable media that provides
storage functionality to store and retrieve various data associated
with the operation of the radar computing device, such as the
software program, code segments and other types of digital data.
The memory may include, for example, removable and non-removable
memory elements such as RAM, ROM, Flash (e.g., SD Card, mini-SD
card, micro-SD Card), magnetic, optical, USB memory devices, and so
forth.
[0020] The display device provides visual display functionality for
the radar computing device and may comprise an LCD (Liquid Crystal
Diode) display, a TFT (Thin Film Transistor) LCD display, an LEP
(Light Emitting Polymer) or PLED (Polymer Light Emitting Diode)
display, and so forth, configured to display text and/or graphical
information such as a graphical user interface. The display may be
backlit via a backlight such that it may be viewed in the dark or
other low-light environments.
[0021] The input device allows the operator to operate the radar
computing device and may be comprised of a keyboard, and/or a
pointing device such as a mouse, trackball or touch screen such as
a capacitive touch screen, a resistive touch screen, an infrared
touch screen, combinations thereof, and the like.
[0022] The radar assembly 104 includes, but is not necessarily
limited to: a transmitter such as a microwave power amplifier, a
modulator such as a microwave switch or phase shifter, a receiver
such as low-noise microwave amplifier, frequency down converter and
an analog to digital converter, and a frequency source(s) such as a
voltage controlled oscillator(s) or a frequency synthesizer(s). An
example radar assembly 104 is described in U.S. Pat. No. 7,817,082,
issued Oct. 19, 2010, which is herein incorporated by reference in
its entirety. The communications cable(s) 106 may be any standard
communication cable used to connect computing devices to
peripherals such as serial, parallel, USB, Ethernet, IEEE 1394, PCI
Express, and so on.
[0023] The radar assembly 104 is connected to a radar antenna 108
through one or more radio frequency (RF) cables 110. The radar
antenna 108 can be any type of high gain antenna such as horn
antenna(s), parabolic dish antenna(s), flat panel antenna(s), and
so on. The RF cable(s) 110 can be any type of low loss microwave
coaxial cable such as RG-58A, RG-223, SR-085, SR-141, and so
on.
[0024] The radar computing device 102 is also connected to an
antenna pointing assembly 112 through the communications cable(s)
106. The antenna pointing assembly 112 can be any type of gimbal,
either electric or hydraulic, that allows the antenna to be pointed
at the obstruction of interest. The radar antenna 108 is mounted to
the antenna pointing assembly 112 by mounting hardware 114 such as
brackets, nuts and bolts, and so on. The radar computing device 102
is also connected to a sensor assembly 116 through communications
cable(s) 106. The sensor assembly 116 is comprised of at least a
range finder, either optical or RF, and an electro-optical camera
such as a visible light camera, a low-light capable visible light
camera, an IR camera, and so on.
[0025] FIG. 2 illustrates an example setup procedure 200 for a
sense through obstruction radar system such as the sense through
obstruction radar system 100 shown in FIG. 1. As shown, the process
is initiated by powering up the radar system 202. The operator then
points the radar antenna 204 using the radar computing device 206.
Images from the sensor assembly camera 208 are used to determine
that the radar antenna is properly pointed 210. Once the radar
antenna is properly pointed 210, the radar is started 212. The
radar range of interest 214 may then be adjusted using the radar
computing device 206 and feedback from the sensor assembly range
finder 216 to adjust the range of the radar. The range of the radar
is set by adjusting the time between the transmitted RF energy and
the start of the receiver RF energy measurement. This time is
calculated using the range provided by the sensor assembly range
finder 216 multiplying it by two (round trip distance) and dividing
by the speed of light. When the radar range is correct 218, the
radar may collect and process radar data 220.
[0026] FIG. 3 illustrates an example radar data processing cycle
300. The cycle (process) 300 is initiated when the radar assembly
302 transmits a radio frequency (RF) pulse 304. The radar assembly
302 then receives the reflected RF energy 306 and performs analog
processing 308 such as filtering, frequency down conversion,
gating, and so on, on the received signal. The processed analog
signal is then converted to a digital signal using an analog to
digital (A/D) converter 310 which is connected to the radar
computing device 312. The radar computing device 312 then processes
the digital signal using digital signal processing (DSP) techniques
314 such as filtering, frequency down conversion, spectral
analysis, and so on. The processed digital signal is then sent to a
target detector 316 to determine how many targets are detected,
their range, and range rates. The range and range rate detection
information is sent to the radar computing device's display 318 for
display to the operator.
[0027] FIG. 4 illustrates an example implementation of the sense
through obstruction radar system shown in FIG. 1. The sense through
obstruction radar system 400 shown is comprised of a radar
computing device 402 that is connected to a radar assembly 404
through one or more communications cables 406. The radar computing
device 402 sets RF parameters for the radar assembly 404 to provide
a RF signal to a radar antenna 408 via one or more RF cables 410.
The radar computing device 402 is also connected to an azimuth and
elevation gimbal 412 through communications cable(s) 406. The
azimuth and elevation gimbal 412 receives antenna pointing commands
from the radar computing device 402 via the communication cable(s)
406. The radar antenna 408 is mounted to the azimuth and elevation
gimbal 412 using mounting hardware 414. The radar computing device
402 is also connected to a range finder 416 through communications
cable(s) 406. The radar computing device 402 is also connected to a
wireless router 418 using one or more network cables 420. A user
interface computing device 422 that hosts the user interface used
by the operator is connected to the wireless router 418 through a
network link 424. The network link 424 can be a network cable(s), a
wireless link such as an 802.11 Wi-Fi, Bluetooth, ZigBee, and so
on. An electro-optical network camera 426 is connected to the
wireless router 418 so that it can provide streaming video to the
user interface computing device 422 or the radar computing device
402. A sensor assembly 428 is mounted on the azimuth and elevation
gimbal 412 using mounting hardware 414. In the implementation
illustrated, the sensor assembly 428 is comprised of a range finder
416 and an electro-optical network camera 426. In other
implementations, it is contemplated that the sensor assembly 428
may include various other types of sensors/sensing equipment. The
sensor assembly 428 is aligned with the radar antennas 408 RF beam
so that the operator can position the center of the RF beam based
on the center of the image provided by the electro-optical network
camera 426 using the azimuth and elevation gimbal 412 and the radar
computing device 402. A positioning system receiver 430 is
connected to the wireless router 418 through the network link 424.
The positioning system receiver 430 can be a Global Positioning
System (GPS) receiver, a GLONASS receiver, a COMPASS receiver, a
GALILEO receiver, a cell tower triangulation receiver, and so on.
The positioning system receiver 430 provides latitude, longitude,
and altitude information to the user interface computing device
422. The wireless router 418 provides wireless links 432 to remote
viewing device(s) 434 so that the information presented on the
display of the user interface computing device 422 can be displayed
on the remote viewing device(s) 434. The remote viewing device(s)
434 can be a computer(s), a laptop computer(s), a tablet
computer(s), a hand-held computer(s) such as an IPOD brand handheld
computer, a smart phone(s) such as an IPHONE brand smart phone, a
BLACKBERRY brand smart phone, or an ANDROID based smart phone, and
so on, or any combination thereof. Power is provided to the
electrical components from a suitable power source such as a
battery (e.g., a 24V battery (not shown)), or the like). The system
includes the software hosted on the radar computing device 402 for
controlling the azimuth and elevation gimbal 412, the radar control
and signal processing software hosted on the radar computing device
402, and the user interface and data display software hosted on the
user interface computing device 422.
[0028] FIG. 5 depicts an example radar antenna assembly 500 of the
sense through obstruction radar system 100 shown in FIG. 1. The
radar antenna assembly 500 includes a horn antenna 502 that is
mounted to a parabolic dish reflector 504 in an offset feed
configuration using support arms 506. Horn antenna 502 and
parabolic dish reflector 504 constitute a high-gain radio frequency
(RF) antenna. Range finder 508 and electro-optical camera 510 are
mounted on support arms 506 on either side of the horn antenna 502
so that they are aligned with the RF beam that is formed from the
RF energy that is reflected from the parabolic dish reflector 504.
This alignment of the center of the RF beam, electro-optical
cameras FOV, and the range finder beam is illustrated in FIG. 6.
This subassembly is mounted to an electro-mechanical azimuth and
elevation antenna pointing device 512.
[0029] FIG. 6 depicts an example radar antenna assembly 600 of the
sense through obstruction radar system 100 shown in FIG. 1. The RF
beam 602 is formed from the RF energy that is transmitted from the
horn antenna 604 and reflected off of the parabolic dish reflector
606 and has a field of view (FOV) 608. An electro-optical camera
610 is mounted next to the horn antenna 604 such that the camera
FOV 612 has its center aligned with the center of the RF beam FOV
608. This center point is indicated by cross-hairs 614. A range
finder 616 is mounted next to the horn antenna 604 such that the
center of the range finder beam 618 is incident upon the center of
the RF beam FOV 608 and the center of the cameras FOV 612.
[0030] FIG. 7 illustrates a radar data processing cycle 700 for the
sense through obstruction radar shown in FIG. 1. The cycle
(process) 700 starts when the radar assembly 702 transmits a radio
frequency (RF) pulse 704. The radar assembly 702 then receives the
reflected RF energy 706 and performs analog processing 708 on the
received signal. The processed analog signal is then converted to a
digital signal using an analog to digital (A/D) converter 710 that
is connected to a radar computing device 712. The radar computing
device 712 then converts the digital signal from the time domain to
the frequency domain using digital signal processing (DSP)
techniques 714 such as a discrete Fourier transform, wavelet
transform, and so on. Additional DSP techniques such as filtering,
are used to suppress the clutter in the signal 716. The processed
digital signal is then sent to a detector 718 that correlates the
signal with a plurality of spectral templates 720 to determine how
many targets are detected, their range, and range rates. The range
and range rate detection information is sent to a tracker 722. The
tracker 722 creates, destroys, and updates tracks (filtered
range/range-rate pairs) based on whether the received
range/range-rate data is associated with an existing track or
represents a new track. When an existing track does not receive an
update from the tracker within a set period of time the track is
eliminated. In one or more implementations, the tracker 722 may
employ nearest neighbor logic to associate new data with existing
tracks and a Kalman Filter, to update and propagate the tracks.
However, it is contemplated that other techniques may be employed
to achieve similar results. Valid track data is furnished to a
computing device display 724, which could be the display connected
to the radar computing device 712, or the display connected to
another computing device that is connected to the radar computing
device 712 using a network as shown in FIG. 4. The radar computing
device 712, which includes or is connected to the display 724, uses
the range-rate information to determine when the micro-Doppler
signature represents a moving or stationary object, and color codes
the displayed track information accordingly.
[0031] FIG. 8 illustrates an example Graphical User Interface (GUI)
800 configured to operate a sense through obstruction radar system
such as the sense through obstruction radar system 100 shown in
FIG. 1 and described above. The GUI 800 may be implemented as a set
of instructions (software) that can be hosted on a user interface
computing device 422 or on another computing device that is
connected to the user interface computing device 422 via a network
as shown in FIG. 4. The GUI 800 furnishes video display
functionality to the operator or other users of the radar system.
In implementations, the video data received from the
electro-optical camera 428 shown in FIG. 4 may be displayed in
real-time 802. Several additional visual elements can be displayed
over the real-time video. For example, the following list is
representative of visual elements that can provide additional
information to the user but does not include all possible useful
visual elements. The first visual overlay includes crosshairs 804
that represent the center of the cameras field of view (FOV) 612
and the center of the RF beams FOV 608 by virtue of the alignment
of the camera FOV 612 and the RF beams FOV 608 as shown in FIG. 6.
The crosshairs 804 help the operator point the azimuth and
elevation gimbal 412, shown in FIG. 4, so that the RF beams FOV
608, shown in FIG. 6, is pointed at the obstruction of interest.
The second visual overlay includes a circle 806 that represents the
RF beams FOV 608, shown in FIG. 6. The circle 806 helps the
operator determine where it is possible for the radar to detect
human micro-Doppler signatures. The third visual overlay includes
the ground/floor indicator 808 that helps the operator position the
elevation angle of the azimuth and elevation gimbal 412, shown in
FIG. 4, so that the center of the RF beams FOV 608, shown in FIG.
6, is at an optimal height for detecting human micro-Doppler
signatures. Another visual overlay may include the track
indicator(s) 810 that represents a valid track or detection of a
micro-Doppler signature. Each valid track may have an associated
track indicator 810 overlaid on the real-time video display 802.
The track indicator(s) 810 can also display the range of the
detection behind the obstruction, in this case the front wall of a
building. This value can change when updated valid track
information is received from the radar computing device 712 shown
in FIG. 7. The track indicator(s) 810 can also be configured to
show the range from the sense through obstruction radar system 100,
shown in FIG. 1, instead of the range behind the obstruction. The
track indicator(s) 810 can be color coded to indicate when the
detection represents a moving or stationary micro-Doppler
signature. The number and types of tracks are shown in the Track
Data area 812 of the GUI 800. The local date and time are shown in
the Local Date/Time area 814 of the GUI 800. The sense through
obstruction radar latitude, longitude, and heading information
provided by the positioning system receiver 430, shown in FIG. 4,
are displayed in the System Information area 816 of the GUI 800.
Also shown in the System Information area 816 is the range of the
obstruction from the sense through obstruction radar provided by
the range finder 416 shown in FIG. 4, and the geographic
coordinates (e.g., latitude and longitude) of the obstruction
computed by the radar computing device 712 using the latitude,
longitude, and/or heading of the radar along with the range to the
obstruction. The Zoom Control area 818 of the GUI 800 may be used
to control the zoom level of the electro-optical camera 428 shown
in FIG. 4. The System Status area 820 of the GUI 800 may be used to
monitor the health of all the communications interfaces. The Gimbal
Control area 822 of the GUI 800 may be used to monitor and control
the azimuth and elevation gimbal 412, shown in FIG. 4. The Display
Control area 824 of the GUI 800 may be used to control the display
of different visual elements or data on the display. The Radar
Start/Stop button 826 may be used to turn the radar assembly 404
shown in FIG. 4 on or off.
CONCLUSION
[0032] Although the subject matter has been described in language
specific to structural features and/or process operations, it is to
be understood that the subject matter defined in the appended
claims is not necessarily limited to the specific features or acts
described above. Rather, the specific features and acts described
above are disclosed as example forms of implementing the
claims.
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