1. Computation Basics : used to define the required standard, a name, title▾

Required Standard*

Select the standard so the engine can confirm if your survey configuration meets specification

Project Name*

Enter the project name so the report can identify which project this assessment is associated with.

User Name*

Enter your name so the report can identify who undertook the assessment.

TPU Computation Date*

Project Duration (Days)*

The project duration is used to compute the tide gauge error arising from the drift rate of the sensor.

TPU Engine Version*

2. Sensor Selection : Select your equipment so the engine can extract the specification correctly▾

Multibeam Sensor*

Select the Multibeam System

Position System*

Select the Positioning System

Attitude Sensor*

Select the Attitude System

3. Sensor Parameters : Specify how you will configure your equipment▾

Sector Angle*

Select the full opening angular sector for the sonar, eg 180 degrees for horizon to horizon, set to 120.5 for 3.5*WD coverage

Ping Rate (Hz)*

Select the pings per second rate. Set to -1 for automatic as fast as possible

Swath Coverage (%)*

Select the Swath Coverage, 100% for FULL Bathymetric Coverage, 200% for Full Seafloor Coverage. For Order 1a set to 110%

Minimum Depth(m)*

Select the Minimum Depth for the survey. This is used to bracket the computations.

Maximum Depth (m)*

Select the Maximum Depth for the survey. This is used to bracket the computations.

Vessel Speed (Kts)*

Vessel speed has a direct impact on data density and feature detection capability.

Mean Column SVP*

The Mean SV for water column is used to compute the THU and TVU on outer beams. This only needs to be approximate for the area of operation.

Acceptable SVP Error*

Acceptable SVP error arises from observing SVP in one location and them moving to a different water body, tide cycle.

4. Attitude Parameters : specify the operational weather window for your survey▾

Maximum Operating Pitch Condition*

The maximum operational PITCH impacts most notebly on outer beams for both TVU and THU.

Maximum Operating Roll Condition*

The maximum operational ROLL impacts most notebly on outer beams for both TVU and THU.

Maximum Operating Heave Condition*

The maximum operational HEAVE impacts the entire ping for TVU.

Patch Test Roll Uncertainty*

Uncertainy associated with an imperfect patch test affects both THU and TVU.

Patch Test Pitch Uncertainty*

Uncertainy associated with an imperfect patch test affects both THU and TVU.

5. Installation Parameters : Specify the offsets on your vessel.▾

GNSS Antenna Offset Uncertainty*

How well you have measured the GNSS antenna is important as it creates an error via lever arm computations contributing to both THU and TVU. This uncertainty is applied for Dx, Dy and Dz

GNSS Antenna to MBES Offset:X*

The Antenna to MBES offset impacts both TVU and THU. sign does not matter

GNSS Antenna to MBES Offset:Y*

The Antenna to MBES offset impacts both TVU and THU. sign does not matter

GNSS Antenna to MBES Offset:Z*

The Antenna to MBES offset impacts both TVU and THU via offset errors. Its always good to minimise these. sign does not matter

IMU to MBES Offset:X*

The IMU to MBES offset creates lever arm sources of error. Its always good to minimise these.

IMU to MBES Offset:Y*

The IMU to MBES offset creates lever arm sources of error. Its always good to minimise these.

IMU to MBES Offset:Z*

The IMU to MBES offset creates lever arm sources of error. Its always good to minimise these.

6. Datum Reduction : Define how you will reduce your data to DATUM using conventional TIDES, DRAFT, SQUAT & LAT▾

Tide Sensor*

Select the Tide reduction source

Tide Gauge Settlement Uncertainty*

The tide gauge may settle into the seafloor. You can select the stability of the tide gauge here.

Tide Model Uncertainty*

The tide model source of error is based on the estimation of uncertainty from tide zoning.

Inferred LAT Uncertainty*

If harmonic constituents Sa/Ssa, P1, K2,ν2, 2N2 are not included in the harmonic analysis.

Draft Sensor Uncertainty*

Select the Draft Sensor.

Squat Model Uncertainty*

The Squat Vs Speed Uncertainty is based how well you have modelled the vessel squat at your calibration phase.

Mean Sea Level Anomaly*

Mean sea level anomaly deals with the effect long term climate events on water levels . They occur at interannual / decadal timescales and even longer term and are more random in nature.

7. Ellipsoid Reduction : Define how you will reduce your data to the ELLIPSOID▾

GNSS Height Calculation Accuracy*

Select the processed GNSS height accuracy. this is a function of receiver, processing and smoothing techniques.

GNSS Buoy Height Accuracy*

Select the GNSS Antenna to Waterline offset accuracy.

Ellipsoid Model Accuracy*

The ellipsoid model source of error is based on the estimation of uncertainty from geoid modelling.

About Tool

References

Australian Hydrographic Office Statement of Requirements (available on request)
IHO Special Publication 44 Edition 6 (2020)
AusSeabed Australian Multibeam Guidelines
Total Vertical Uncertainty for AUV
QPS Total Vertical Uncertainty confluene page
Modelling Bathymetric Uncertainty, R.Hale
Pilbara Ports Hydrogrpahic Survey Standards and Deliverables
wikipedia Propagation of Uncertainty