Abstract: The present disclosure is directed towards direction finding (DF) systems that can detect and locals a radio frequency (RF) signal (e.g. an emergency beacon) is two dimensions (i.e., azimuth and elevation). In one embodiment, a DF system comprises an array of multipolarized loop antennas coupled to a beamformer which provides monopole, dipole, and loop antenna element modal signals. The DF system may also comprise a multi-channel digital receiver system coupled to the beamformer. The multi-channel digital receiver system is configured to receive modal signals provided thereto from the beamformer which can be used for accurate two-dimensional geolocation of RF signals including, but not limited to, location of RF emergency beacon sources.

Abstract: The present disclosure is directed towards direction finding (DF) systems that can detect and locals a radio frequency (RF) signal (e.g. an emergency beacon) is two dimensions (i.e., azimuth and elevation). In one embodiment, a DF system comprises an array of multipolarized loop antennas coupled to a beamformer which provides monopole, dipole, and loop antenna element modal signals. The DF system may also comprise a multi-channel digital receiver system coupled to the beamformer. The multi-channel digital receiver system is configured to receive modal signals provided thereto from the beamformer which can be used for accurate two-dimensional geolocation of RF signals including, but not limited to, location of RF emergency beacon sources.

Abstract: Described are a method and system for detecting and locating changes in an underground region. Changes are detected using a mobile coherent change detection ground penetrating radar (GPR). The GPR system is located on a mobile platform that makes two more measurement passes over the same route to acquire GPR images of an underground region at different times. A lateral offset between the GPR images for the two different times is determined and applied to one of the GPR images to generate a GPR shifted image that is spatially aligned with the other GPR image using a correlation process or other technique. A GPR difference image is generated from the GPR shifted image and the other GPR image. The GPR difference image includes data representative of changes to the underground region that occurred between the two measurement passes.

Abstract: Described are a method and a system for localization of a vehicle. The method includes the acquisition of SPR images of a subsurface region along a vehicle track. Acquired SPR images are compared to SPR images previously acquired for a subsurface region that at least partially overlaps the subsurface region along the vehicle track. In some embodiments, the comparison includes an image correlation procedure. Location data for the vehicle are determined based in part on location data for the SPR images previously acquired for the second subsurface region. Location data can be used to guide the vehicle along a desired path. The relatively static nature of features in the subsurface region provides the method with advantages over other sensor-based navigation systems that may be adversely affected by weather conditions, dynamic features and time-varying illumination. The method can be used in a variety of applications, including self-driving automobiles and autonomous platforms.

Abstract: Described are a method and system for detecting and locating changes in an underground region. Changes are detected using a mobile coherent change detection ground penetrating radar (GPR). The GPR system is located on a mobile platform that makes two more measurement passes over the same route to acquire GPR images of an underground region at different times. A lateral offset between the GPR images for the two different times is determined and applied to one of the GPR images to generate a GPR shifted image that is spatially aligned with the other GPR image using a correlation process or other technique. A GPR difference image is generated from the GPR shifted image and the other GPR image. The GPR difference image includes data representative of changes to the underground region that occurred between the two measurement passes.

Abstract: Described are a method and a system for localization of a vehicle. The method includes the acquisition of SPR images of a subsurface region along a vehicle track. Acquired SPR images are compared to SPR images previously acquired for a subsurface region that at least partially overlaps the subsurface region along the vehicle track. In some embodiments, the comparison includes an image correlation procedure. Location data for the vehicle are determined based in part on location data for the SPR images previously acquired for the second subsurface region. Location data can be used to guide the vehicle along a desired path. The relatively static nature of features in the subsurface region provides the method with advantages over other sensor-based navigation systems that may be adversely affected by weather conditions, dynamic features and time-varying illumination. The method can be used in a variety of applications, including self-driving automobiles and autonomous platforms.

Abstract: Described are a method and system for detecting and locating changes in an underground region. Changes are detected using a mobile coherent change detection ground penetrating radar (GPR). The GPR system is located on a mobile platform that makes two more measurement passes over the same route to acquire GPR images of an underground region at different times. A lateral offset between the GPR images for the two different times is determined and applied to one of the GPR images to generate a GPR shifted image that is spatially aligned with the other GPR image using a correlation process or other technique. A GPR difference image is generated from the GPR shifted image and the other GPR image. The GPR difference image includes data representative of changes to the underground region that occurred between the two measurement passes.