Prior to these deployment steps, SPRINT and SPRINT-Nav systems should be configured with suitable aiding, time synchronisation, installation parameters applied, outputs configured, and the INS algorithm set to use DVL, pressure and position aiding when available.

AHRS settling

The SPRINT / SPRINT-Nav AHRS algorithm will take 10 minutes to settle from start-up.

The AHRS uses the default Latitude set in the SPRINT software, this must be updated to the correct latitude prior to every dive.

The ROV can be moving (early decent) whilst the AHRS settling, once settled the AHRS status LED in SPRINT software will turn green.

INS initialisation

The INS algorithm requires a starting position to initialise, which (In normal operation) is provided by the first accepted USBL position during decent.

Once initialised, the INS LED in SPRINT software will turn green (as well as USBL and Depth). The DVL status LED will turn green when bottom lock has been acquired.

Vehicle descent and INS initialisation sequence