A thorough analysis of various geometries for a dynamic calibration target for through-wall and through-rubble radar

Author(s):  
Ram M. Narayanan ◽  
Michael J. Harner ◽  
John R. Jendzurski ◽  
Nicholas G. Paulter
Instruments ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 37
Author(s):  
Ram M. Narayanan ◽  
Michael J. Harner ◽  
John R. Jendzurski ◽  
Nicholas G. Paulter

Through-wall and through-barrier motion-sensing systems are becoming increasingly important tools to locate humans concealed behind barriers and under rubble. The sensing performance of these systems is best determined with appropriately designed calibration targets, which are ones that can emulate human motion. The effectiveness of various dynamic calibration targets that emulate human respiration, heart rate, and other body motions were analyzed. Moreover, these targets should be amenable to field deployment and not manifest angular or orientation dependences. The three targets examined in this thesis possess spherical polyhedral geometries. Spherical geometries were selected due to their isotropic radar cross-sectional characteristics, which provide for consistent radar returns independent of the orientation of the radar transceiver relative to the test target. The aspect-independence of a sphere allows for more accurate and repeatable calibration of a radar than using a nonspherical calibration artifact. In addition, the radar cross section (RCS) for scattering spheres is well known and can be calculated using far-field approximations. For Doppler radar testing, it is desired to apply these calibration advantages to a dynamically expanding-and-contracting sphere-like device that can emulate motions of the human body. Monostatic RCS simulations at 3.6 GHz were documented for each geometry. The results provide a visual way of representing the effectiveness of each design as a dynamic calibration target for human detection purposes.


2017 ◽  
Author(s):  
Michael J. Harner ◽  
Matthew J. Brandsema ◽  
Ram M. Narayanan ◽  
John R. Jendzurski ◽  
Nicholas G. Paulter

Author(s):  
Tianlin Wang ◽  
Christopher S. Ruf ◽  
Scott Gleason ◽  
Andrew J. O'Brien ◽  
Darren S. McKague ◽  
...  

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2947
Author(s):  
Ming Hua ◽  
Kui Li ◽  
Yanhong Lv ◽  
Qi Wu

Generally, in order to ensure the reliability of Navigation system, vehicles are usually equipped with two or more sets of inertial navigation systems (INSs). Fusion of navigation measurement information from different sets of INSs can improve the accuracy of autonomous navigation effectively. However, due to the existence of misalignment angles, the coordinate axes of different systems are usually not in coincidence with each other absolutely, which would lead to serious problems when integrating the attitudes information. Therefore, it is necessary to precisely calibrate and compensate the misalignment angles between different systems. In this paper, a dynamic calibration method of misalignment angles between two systems was proposed. This method uses the speed and attitude information of two sets of INSs during the movement of the vehicle as measurements to dynamically calibrate the misalignment angles of two systems without additional information sources or other external measuring equipment, such as turntable. A mathematical model of misalignment angles between two INSs was established. The simulation experiment and the INSs vehicle experiments were conducted to verify the effectiveness of the method. The results show that the calibration accuracy of misalignment angles between the two sets of systems can reach to 1″ while using the proposed method.


Author(s):  
Serena Cattari ◽  
Stefania Degli Abbati ◽  
Sara Alfano ◽  
Andrea Brunelli ◽  
Filippo Lorenzoni ◽  
...  

2014 ◽  
Vol 8 (3) ◽  
Author(s):  
Michael Winek ◽  
Robert Sweet ◽  
Timothy M. Kowalewski

1948 ◽  
Vol 15 (3) ◽  
pp. 248-255
Author(s):  
E. T. Habib

Abstract In mechanical gages used to measure the pressure from an underwater explosion, small copper cylinders are compressed at high speeds. This paper describes the test apparatus designed for the dynamic calibration of these cylinders, presents the results obtained with this apparatus, and compares these results with those obtained by other experimenters.


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