Novatel OM-20000122 Alignment on a Moving Vessel Aided Transfer Alignment, Unaided Alignment

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SPAN-CPT Dual-Antenna

Chapter 4

Alternately, the angular offset between the dual-antenna baseline (from primary GNSS antenna to secondary GNSS antenna) and the IMU frame forward axis is entered directly via the EXTHDGOFFSET command.

We recommend entering the lever arms rather than entering the angular offset as this is easier to measure and will lead to better overall accuracy.

Refer to the SPAN on OEM6 Firmware Reference Manual (OM-20000144) for the syntax of the above commands.

As with all ALIGN-capable products, the GNSS baseline solution is available from the GPHDT and HEADING logs. For INS heading, use INSATT or INSPVA.

The SPAN system can be configured for different alignment routines depending on the motion conditions experienced during the alignment period. For example, in marine applications, the dynamics required for either a coarse or kinematic alignment cannot be guaranteed, so a different alignment routine is required.

The different alignment routines are described in the following sections.

4.2.1Alignment on a Moving Vessel - Aided Transfer Alignment

This alignment routine is the preferred dual antenna alignment method. It is used if the alignment mode is set to AIDED_TRANSFER using the ALIGNMENTMODE command, and can be used if the alignment mode is set to AUTOMATIC.

If your vehicle is not stationary during the alignment, such as may be the case on a ship, use the Aided Transfer Alignment routine. This alignment method uses the ALIGN baseline solution to perform an instantaneous alignment of the vehicle attitude.

The alignment happens instantaneously after the receiver establishes communication with the IMU and computes a verified, fixed integer, ALIGN solution. The INS status changes to INS_ALIGNMENT_COMPLETE or INS_SOLUTION_GOOD, depending on the variances of the ALIGN solution, and the measured lever arm/external heading offset.

To guarantee the use of this alignment mode, the configuration command ALIGNMENTMODE must be sent to the receiver:

ALIGNMENTMODE AIDED_TRANSFER

4.2.2Alignment on a Stationary Vehicle - Aided Static Alignment

An alternative to the aided transfer alignment, the ALIGN heading can be used as a seed for a coarse static alignment. In this mode, the standard coarse alignment routine runs given the initial azimuth value. As with the transfer alignment, the first verified fixed RTK solution is used to provide the alignment seed after which the coarse alignment (INS_ALIGNING) begins. After the coarse alignment is complete, the INS status changes to INS_ALIGNMENT_COMPLETE. After the attitude accuracy has converged, the INS status changes to INS_SOLUTION_GOOD. This alignment mode is useful if the initial vehicle roll is more than 20 degrees.

To use this alignment mode, the configuration command ALIGNMENTMODE must be sent to the receiver.

ALIGNMENTMODE AIDED_STATIC

4.2.3Unaided Alignment

The unaided alignment sets the SPAN system to use only single antenna alignment options (static, kinematic or manual alignment).

To use this alignment mode, the configuration command ALIGNMENTMODE must be sent to the receiver.

ALIGNMENTMODE UNAIDED

SPAN-CPT User Manual Rev 8

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Contents SPAN-CPT Return instructions Proprietary Notice WarrantyTable of Contents Technical Specifications Figures Tables Contact Information NovAtel Knowledge Base Before Contacting Customer SupportFCC Notices Industry CanadaCE Notice Hazard Impact Lightning Protection Installation and Grounding ProcedureWhat is the hazard? Weee NoticePrimary and Secondary Lightning Protection Ref # Description Fundamentals of GNSS+INS IntroductionSystem Components Related Documents and InformationConventions SPAN-CPT Hardware SPAN-CPT InstallationRequired Equipment ManualsTypical SPAN-CPT Set Up Radio COM2 Hardware Set UpMount the SPAN-CPT Mount the AntennaConnect the Gnss Antenna Connect PowerConnect the I/O Strobe Signals Battery Isolator Auxiliary Vehicle MainBatteryConnect a Computer to the SPAN-CPT Can Bus Odometer ConnectionOdometer Requirements Cable Modification for SPAN-CPT Cable Cable Modification for Kistler WPT CableSPAN-CPT Operation Definition of Reference Frames Within SpanLocal Level Frame Full Mapping Definitions Span Body FrameVehicle Frame Enclosure FrameUse NovAtel Connect to Communicate Communicating with the SPAN-CPT SystemChapter SPAN-CPT Operation SPAN-CPT Configuration with NovAtel Connect Software ConfigurationGnss Configuration Span IMU ConfigurationReal Time Operation Ascii System Start-Up and Alignment TechniquesSetimuorientation Default Kinematic AlignmentNavigation Mode Manual AlignmentDual Antenna Alignment Wheel Sensor Update Logic Azimuth Sources on a Span SystemCourse Over Ground Inertial Azimuth Align AzimuthLogs with Azimuth data Data Collection Solution ParametersData Collection for Post-Processing  Logging RestrictionVariable Lever Arm Enabling L-BandNovAtel Correct with TerraStar OmniSTAR Veripos Marine SubscriptionsChapter SPAN-CPT Operation SPAN-CPT Dual-Antenna InstallationSecondary Configuring Span with Align on SPAN-CPTPower Supply Chapter SPAN-CPT Dual-AntennaAlignment on a Moving Vessel Aided Transfer Alignment Alignment on a Stationary Vehicle Aided Static AlignmentUnaided Alignment Automatic Alignment Mode Automatic Alignment default Span Align Attitude UpdatesFirmware Updates and Model Upgrades Firmware UpdatesNovAtel Firmware and Software Model Upgrades Authorization CodeUpdating or Upgrading Using the WinLoad Utility Transferring Firmware FilesTypes of Firmware Files Open a File to Download Using the WinLoad UtilitySearching for Card Updating using SoftLoad CommandsSoftloadsrec S-RECORD Working with S-RecordsUpgrading Using the Auth Command Key Firmware CommandsUpgrade Procedure KVH IMU Sensor Specifications Technical SpecificationsSPAN-CPT Technical Specifications Hardware Specification for SPAN-CPTPower Specifications Electrical and Environmental SpecificationsSPAN-CPT Side and Perspective View SPAN-CPT Mechanical DrawingsSPAN-CPT Top, Front and Bottom View SPAN-CPT 60723108 KVH Development Terminated Cable Pin-Out SPAN-CPT CableFemale Male SPAN-CPT 60723107 KVH Standard Un-terminated Cable Pin-Out Pin Function Wire Pair Wire ColorReplacement Parts Accessories and OptionsSPAN-CPT System Appendix C Frequently Asked QuestionsOM-20000122 Rev March
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