DSU-33D/B Proximity Sensor

The DSU-33D/B Proximity Sensor is an all-weather, battery-operated, active, radio-frequency, ranging radar. It is a single-mission device capable of operating in an electronic countermeasure environment (ECM).

The sensor mounts on and provides a proximity function for the MK 80 and M117 series general purpose bombs. The sensor is capable of both high- and low-drag releases, and it meets the unique requirements of the U.S. Air Force and Navy.

For the Air Force and Navy, bombs are equipped with an FMU-139/B or FMU-152/B bomb fuze, an FZU-48/B or FZU-55/B bomb initiator, and a filtered power-cable assembly. Mix-and-match combinations of fuze, sensor and initiator provide the lowest-cost alternative to fuze/sensor in one hardware package.

Provisions for both ground and in-flight safety are incorporated as integral design features to ensure that the sensor will operate the fuze only under specific and selected conditions. The DSU-33D/B has passed appropriate environmental tests.

The sensor features advanced electronics technology, solid-state circuit design and highly reliable parts. It is subjected to extensive testing during all production stages.

In terms of accuracy, the DSU-33D/B allows for multiple drop configurations. The sensor-processor signal returns from the weapon release all the way to the ground. When jamming occurs, the ground signal overcomes the jamming signal and initiates an above-ground burst, and when no jamming is present, the sensor provides a very accurate height of burst.

Performance Characteristics

Airspeed 250 to 700 KCAS
Delivery altitude 200 to 50,000 ft
Power supply Battery-initiated by FZU-48 Initiator, FMU-152/B Fuze, FZU-55/B Initiator, or Navy FFCS
Height of burst 14 to 26 ft (2 sigma factory requirement)
Closing velocity for fuzing 75 to 1,400 ft/sec
Weight Less than 5 lb
Reliability 95% after 10 yr
Delivery modes
  • Drop: Single or multiple
  • Salvo: 6-bomb simultaneous release
  • Ripple: 24-bomb release
  • LOFT/TOSS and lateral TOSS
  • Dive angles: +45 deg to –60 deg referenced to horizontal
  • High or low drag
Operational life 200 sec minimum
Shelf life 10 yr minimum
Service life 5 yr minimum cumulative days outside storage and assembled in a warhead
DSU-33D/B Proximity Sensor data sheet
.pdf download