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AN/ASN-128B/C Doppler Navigation Set

Provides integrated GPS and Doppler navigation/guidance

AN/ASN-128B/C Doppler navigation set

AN/ASN-128B/C Doppler navigation set

The AN/ASN-128B/C Doppler/GPS navigation set provides the complementary advantages of a Global Positioning System (GPS) receiver and a self-contained Doppler navigation system. System installation and aircraft modifications have been minimized by embedding a Trimble one-card GPS receiver into the signal data converter (SDC) unit.

The AN/ASN-128B/C provides continuous velocities, navigation and guidance information. When both Doppler and GPS are available, the GPS accurately initializes and automatically updates Doppler present position. If the GPS is lost, the Doppler continues to provide accurate velocities for hover and navigation. If the Doppler is in memory, the GPS continues to provide accurate present position; in each case navigation continues uninterrupted.

AN/ASN-128B/C Features:

  • Contains embedded GPS receiver - military and civilian-only code units are available
  • Doppler navigation automatically selected when GPS is not available
  • Existing ASN-128s can be converted to ASN-128B/C; U.S. Army has over 2000 conversions on order - can also be provided as a totally new system
  • CDU has enhanced display and control capabilities, high-throughput CPU, expanded memory for growth
  • RTA, LRU installation and existing helicopter cabling unchanged - add GPS antenna, cabling
  • ASN-128C contains MIL-STD-1553 interface in CDU

AN/ASN-128B/C computer display unit (CDU):

  • Four-line/64 alphanumeric character display plus paging provides greatly expanded display and data entry capability

  • Displays all navigation and GPS data

  • Displays UTC, high-resolution latitude/longitude data, GPS test mode status, crypto key status, estimated position error, number of space vehicles being tracked

  • New 10 MIPS CPU and expanded memory for greatly increased processing capability

Steering Hover Indicator Unit (optional):

The Steering Hover Indicator Unit (SHIU) has two modes of operation.

In the navigation (NAV) mode, the SHIU provides the pilot with a display of ground speed, distance-to-go, and left/right steering information to the destination selected on the CDU.

In the hover (HOV) mode, the three pointers indicate the values of three orthogonal components of aircraft ground velocity (along heading, across heading, and vertical). By flying the aircraft to maintain these displayed values at zero, the pilot can hover the helicopter without visual reference to the ground.

 

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