Synthetic aperture radar system and method for local positioning
First Claim
1. A positioning system, comprising:
- a passive, isotropic reflecting landmark at a fixed position; and
a device configured to transmit an electromagnetic pulse, the pulse having a polarization;
the device further configured to receive a return signal over a period of time, the return signal including a reflected pulse from the landmark, and to process the return signal so as to isolate the reflected pulse from the return signal and to determine a range from the device to the reflecting landmark;
the reflecting landmark comprising;
a first passive reflector for reflecting electromagnetic pulses;
a second passive reflector for reflecting electromagnetic pulses; and
a static structure configured to statically position the second passive reflector at an angle relative to the first passive reflector, wherein the angle is about 90°
;
the device includinga data processor;
at least one program module, executed by the data processor, the at least one program module containing instructions for;
transmitting the pulse multiple times, each transmission of the pulse having a respective transmission beam pattern with a null over a different respective range of angles;
determining from the return signals from the multiple pulse transmissions a first set of range candidates, each range candidate representing a possible range to the landmark, each range candidate having an associated range of angles; and
analyzing the range of angles associated with each range candidate to produce a reduced set of range candidates that are consistent with one or more potential landmark positions.
2 Assignments
0 Petitions
Accused Products
Abstract
A positioning system includes a passive, isotropic reflecting landmark at a fixed position and a device. The device transmits an electromagnetic pulse having a circular polarization and receives a return signal over a period of time. The return signal includes a reflected pulse from the reflecting landmark. The processes the return signal to isolate the reflected pulse from the return signal and to determine a range from the device to the reflecting landmark. The reflecting landmark includes a first passive reflector, a second passive reflector, and a static structure configured to statically position the second passive reflector at an angle relative to the first passive reflector. The device optionally moves in a particular direction while receiving the return signal, detects a Doppler shift in the reflected pulse portion of the return signal, and determines an angle between the particular direction and a straight line between the device and the landmark.
-
Citations
16 Claims
-
1. A positioning system, comprising:
-
a passive, isotropic reflecting landmark at a fixed position; and a device configured to transmit an electromagnetic pulse, the pulse having a polarization;
the device further configured to receive a return signal over a period of time, the return signal including a reflected pulse from the landmark, and to process the return signal so as to isolate the reflected pulse from the return signal and to determine a range from the device to the reflecting landmark;the reflecting landmark comprising; a first passive reflector for reflecting electromagnetic pulses; a second passive reflector for reflecting electromagnetic pulses; and a static structure configured to statically position the second passive reflector at an angle relative to the first passive reflector, wherein the angle is about 90°
;the device including a data processor; at least one program module, executed by the data processor, the at least one program module containing instructions for; transmitting the pulse multiple times, each transmission of the pulse having a respective transmission beam pattern with a null over a different respective range of angles; determining from the return signals from the multiple pulse transmissions a first set of range candidates, each range candidate representing a possible range to the landmark, each range candidate having an associated range of angles; and analyzing the range of angles associated with each range candidate to produce a reduced set of range candidates that are consistent with one or more potential landmark positions. - View Dependent Claims (2, 3)
-
-
4. A positioning system, comprising
a passive, isotropic reflecting landmark at a fixed position; -
a device configured to transmit an electromagnetic pulse, the pulse having a polarization;
the device further configured to preferentially receive a return signal having the polarization over a period of time, the return signal including a reflected pulse from the reflecting landmark, and to process the return signal so as to isolate the reflected pulse from the return signal and to determine a range from the device to the reflecting landmark;the reflecting landmark comprising; a first passive reflector for reflecting electromagnetic pulses; a second passive reflector for reflecting electromagnetic pulses; and a static structure configured to statically position the second passive reflector at an angle relative to the first passive reflector, wherein the angle is about 90°
;a vehicle locomotion mechanism for moving the device in a particular direction, at a velocity; a data processor, and; at least one program module, executed by the data processor, the at least one program module containing instructions for; transmitting the pulse at a first position of the device and determining from the received return signal a first set of range candidates, each range candidate representing a possible range to the reflecting landmark; transmitting the pulse at a second position of the device and determining from the received return signal a second set of range candidates; and processing the first and second sets of range candidates to produce a reduced set of range candidates that are consistent with one or more potential reflecting landmark positions. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
Specification