Abstract: An interrogator and system employing the same. In one embodiment, the interrogator includes a receiver configured to receive a return signal from a tag and a sensing module configured to provide a time associated with the return signal. The interrogator also includes a processor configured to employ synthetic aperture radar processing on the return signal in accordance with the time to locate a position of the tag.

Abstract: A control and processing system for use with an interrogator and an interrogation system employing the same. In one embodiment, the control and processing system includes a correlation subsystem having a correlator that correlates a reference code with a reply code from a radio frequency identification (RFID) tag and provides a correlation signal therefrom. The control and processing system also includes a decision subsystem that verifies a presence of the RFID tag as a function of the correlation signal.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RFID object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: A data encryption and decryption system securely geoencrypts data using location-dependent navigation signals. To increase the entropy of the cryptographic key to guard against a brute-force attack, geoencryption is made to depend on largely time-independent characteristics of the navigation signals that are not easily spoofed, including the time difference of arrival, the envelope-to-cycle difference, the differential signal-to-noise, the signal envelope shape, and the directions of arrival of the navigation signal set.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RIFD object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: An interrogator and system employing the same. In one embodiment, the interrogator includes a receiver configured to receive a return signal from a tag and a sensing module configured to provide a time associated with the return signal. The interrogator also includes a processor configured to employ synthetic aperture radar processing on the return signal in accordance with the time to locate a position of the tag.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RFID object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RFID object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RIFD object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: A data encryption and decryption system securely geoencrypts data using location-dependent navigation signals. To increase the entropy of the cryptographic key to guard against a brute-force attack, geoencryption is made to depend on largely time-independent characteristics of the navigation signals that are not easily spoofed, including the time difference of arrival, the envelope-to-cycle difference, the differential signal-to-noise, the signal envelope shape, and the directions of arrival of the navigation signal set.

Abstract: An interrogation system employable with an object having a radio frequency identification (RFID) tag and method of operating the same. In one embodiment, the interrogation system includes a database having prior knowledge about the object, and an interrogator that scans the RFID tag and discerns additional information therefrom about the object. The interrogator still further includes a control system that identifies the object based on the prior knowledge and the additional information.

Abstract: A data loader device is used to convey digital data in a secure manner to another device. The data loader may be fixed (referred to as a Class_A loader) or portable (referred to as a Class_B loader). The data loader encrypts the digital data using a location-identity that permits the digital data to be transferred only if the data loader is disposed at an appropriate location. The fixed data loader remains in a stationary location, and a device to be loaded is brought to the data loader for loading. The portable data loader can be loaded by the fixed data loader, and then transported to another location to load a recipient device. The digital data that is conveyed is unrestricted in nature, and can include keys, navigational information, watermarking parameters, or any other digital content requiring secure delivery. In an embodiment, the data loader device includes a “no-move” system that precludes compromise of data contained therein if the data loader device is moved.

Abstract: An interrogation system employable with an object having a radio frequency identification (RFID) tag and method of operating the same. In one embodiment, the interrogation system includes a database having prior knowledge about the object, and an interrogator that scans the RFID tag and discerns additional information therefrom about the object. The interrogator still further includes a control system that identifies the object based on the prior knowledge and the additional information.

Abstract: A reply code for a radio frequency identification (RFID) tag, a method of improving a reply code for a radio frequency identification (RFID) tag for interrogation by an interrogator and an RFID tag employing the same. In one embodiment, the reply code includes a preamble having information about a quality of a clock associated with the RFID tag. The reply code also includes a tag identification (ID) code providing a digital signature for the RFID tag. The reply code still further includes an aftamble located aft of the preamble and having information about the quality of the clock. The aftamble cooperates with the preamble to improve a quality of the reply code for interrogation by an interrogator.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RIFD object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RFID object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: An interrogator, methods of discerning the presence of an object, and interrogation systems employing the same. In one embodiment, the interrogation systems include multiple interrogators that communicate with a base command unit to track a location of an object. In another embodiment wherein the object is an RFID object (e.g., an object with an RFID tag), the interrogators employ signal processing techniques such as precharging the RFID object, and correlating a reference code with a reply code from the RIFD object using selected techniques to increase a sensitivity of the interrogator, especially for adverse environments. In other embodiments, the interrogation systems include variations of metal instruments and sponges employed therewith. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.

Abstract: An interrogation system employable with an object having a radio frequency identification (RFID) tag and method of operating the same. In one embodiment, the interrogation system includes a database having prior knowledge about the object, and an interrogator that scans the RFID tag and discerns additional information therefrom about the object. The interrogator still further includes a control system that identifies the object based on the prior knowledge and the additional information.

Abstract: A reply code for a radio frequency identification (RFID) tag, a method of improving a reply code for a radio frequency identification (RFID) tag for interrogation by an interrogator and an RFID tag employing the same. In one embodiment, the reply code includes a preamble having information about a quality of a clock associated with the RFID tag. The reply code also includes a tag identification (ID) code providing a digital signature for the RFID tag. The reply code still further includes an aftamble located aft of the preamble and having information about the quality of the clock. The aftamble cooperates with the preamble to improve a quality of the reply code for interrogation by an interrogator.

Abstract: A control and processing system for use with an interrogator and an interrogation system employing the same. In one embodiment, the control and processing system includes a correlation subsystem having a correlator that correlates a reference code with a reply code from a radio frequency identification (RFID) tag and provides a correlation signal therefrom. The control and processing system also includes a decision subsystem that verifies a presence of the RFID tag as a function of the correlation signal.