UK SBS PR16272 North Seeking Attitude Heading Reference System (AHRS)

Tender description

*** This tender requirement was abandoned prior to a Contract award decision. *** Quantity up to a maximum of 3 geographical North Seeking Attitude Heading Reference Systems (AHRS) are required for the Autosub Long Range (ALR) AUV programme. The critical performance requirement is the heading accuracy. The AHRS will be operated with uncertain velocity and position inputs at high geographical latitude. They must be certified to operate under these conditions and the performance quantified. The supplier is asked to quote for delivery and price for 3 of the AHRS. Background The primary purpose of the system is to provide as accurate as possible heading estimates in real time to the AUV system. Update rate should be 1 Hz minimum. Roll and pitch information is also needed by the AUV, but for the applications considered, the accuracy required for these will pose no significant technical challenge. The AHRS system will be provided with velocity updates, but as the AUV will not be within DVL bottom track range at all times (when it will rely on speed through the water measurements), the system performance accuracy must be characterised for a given (unknown at run time) error in the velocity aiding. Furthermore, although the system will be provided with position updates, there will be occasions when position error (critically, the latitude error) is moderately large. Therefore the system must be characterised for moderate latitude errors. The AHRS must be declared to operate at, and with accuracy characterised at, high latitudes, with the unit is aided with erroneous velocity (or speed) and latitude.