Accession Number : AD0902115

Title :   Environmental Sensor Program.

Descriptive Note : Final rept. Jun 71-Mar 72,

Corporate Author : AEROJET ORDNANCE CO DOWNEY CA

Personal Author(s) : Newman, Charles

Report Date : MAR 1972

Pagination or Media Count : 31

Abstract : The objective of this program was to investigate the feasibility of using a Hall-effect magnetic sensor to detect safe separation of the bomb from the aircraft. The approach was to use the distortion of the earth's magnetic field caused by the presence of the aircraft as a safe-separation signal by installing a sensor in a test vehicle (general-purpose bomb) capable of release from the aircraft. The threshold signal is obtained by comparing the magnetic field in the presence of the aircraft (specifically, at the time of release) with the magnetic field without the presence of the aircraft (essentially, the condition at safe separation). Three Hall-effect magnetic sensors were orthogonally mounted in the bomb charging well to measure the three components of magnetic field. The three outputs were amplified, the necessary arithmetic operations were performed to add them vectorially, and the signal at release was sampled and compared with subsequent signal levels until the safe-separation threshold was reached. The single flight test indicated sensor function, but subsequent sponsor ground tests showed that sensor sensitivity and stability in this present configuration are inadequate to detect safe separation. It was concluded that this approach shows promise, although feasibility has not been demonstrated. Further study should be conducted to (1) investigate the AC field surrounding the aircraft as a possible candidate for a safe-separation indicator, (2) consider a Hall-effect sensor which is less sensitive to thermal drift and (3) investigate carrier-type amplifier and logic circuitry to solve the balancing and sensitivity problems. (Author)

Descriptors :   (*MAGNETIC DETECTORS, HALL EFFECT), (*GENERAL PURPOSE BOMBS, DETECTORS), MAGNETIC FIELDS, TIME, LOGIC CIRCUITS, DRAG, DISTORTION, SEPARATION, SENSITIVITY, STABILITY, BOMB FUZES, TAIL FUZES, NOSE FUZES, CONTROL SYSTEMS, FLIGHT TESTING, SAFETY, ALTERNATING CURRENT.

Subject Categories : Magnetic & Electric Fld Detection & Detectors
      Ammunition and Explosives
      Aerial Bombs

Distribution Statement : APPROVED FOR PUBLIC RELEASE