摘要: |
The objective of this project was to demonstrate the performance of an electromagnetic system optimized for detection of small ordnance targets, such as 20mm and 37mm projectiles, at depths greater than the standard 11x diameter metric currently employed. The performance goal for this project was 20x the target diameter. Classification of targets was not an expressed objective of the project, except that considerable non-ordnance items of this size were expected to be detected by the system, so an approach for excluding these items from dig lists was needed. Classification of the sort demonstrated by cued instruments was beyond the expected capabilities of the data produced by this instrument. Ultimately, classification using inversion polarizabilities proved both possible and effective. A total of four field operations were carried out. The first was a feasibility study using the one half of the existing airborne system without modification. The second was an initial shake- down of the modified system to determine the optimal field settings (base frequency, survey speed, platform configuration, transmitter power, vehicle offset, filter parameters, etc.). The third was a preliminary field test to ensure proper operability of the system at the specified settings before the fourth and final demonstration. The initial feasibility study was conducted prior to the contract award. The feasibility study and initial shake-down were both conducted at the Camp Sibert Geophysical Prove Out (GPO) grid with the assistance of the U.S. Army Engineering Support Center, Huntsville (USAESCH). The preliminary field test was conducted at Battelle s West Jefferson, Ohio UXO Test Grid. The final demonstration was conducted at the Aberdeen Proving Ground (APG) Geophysical Test Center. |