HYPACK Multibeam Training Seminar HYCUBE HYPACK ® MULTIBEAM COURSE 4/24/2017 HYPACK Multibeam Training Seminar

HYCUBE: HYPACK’s Implementation of CUBE 4/24/2017 HYPACK Multibeam Training Seminar

HYPACK Multibeam Training Seminar CUBE Combined Uncertainty and Bathymetric Estimator Intended to Speed Processing of Multibeam Data. Developed by Dr. Brian Calder of CCOM-UNH. A statistical approach to cleaning multibeam data. 4/24/2017 HYPACK Multibeam Training Seminar

Introduction – the basics HYSWEEP SURVEY MBMAX HYCUBE HSX HS2 XYZ Z-Values Uncertainty Ratio # of Hypotheses HYPACK Multibeam Training Seminar 4/24/2017

HYPACK Multibeam Training Seminar CUBE Terminology CUBE Node: An X-Y point where CUBE will make depth estimates based on the surrounding data points. CUBE Nodes are ‘spaced’ at User Defined fixed distances, resulting in a square grid. CUBE Nodes Neighborhood Data Points from HS2 File HYPACK Multibeam Training Seminar 4/24/2017

HYPACK Multibeam Training Seminar CUBE Terminology CUBE Nodes Neighborhood Data Points from HS2 File CUBE Neighborhood: The area surrounding a CUBE Node where depths can influence the ‘hypotheses’ HYPOTHESIS: A possible depth estimate at a node. A CUBE Node can have multiple ‘hypotheses’. Note: CUBE ‘hypotheses’ are not actual soundings, but are estimates of depth at each node, based upon the data points in the node’s neighborhood. HYPACK Multibeam Training Seminar 4/24/2017

Cube Grid and Neighborhoods Nodes Neighborhood Data Points from HS2 File A series of CUBE nodes make a CUBE GRID. Soundings about the neighborhood of each node are used to generate depth estimates for the node (Hypotheses). If there are multiple depth hypotheses at a node, CUBE selects its best estimate of the depth. HYPACK Multibeam Training Seminar 4/24/2017

HYPACK Multibeam Training Seminar First Step HYSWEEP SURVEY HSX MBMAX HS2 HYCUBE XYZ Requires Minimal to No Pre-Editing Must be in HS2 format, so you must get to Phase 2 MBMAX Recommended that you Apply and Run some Filters in Phase 2 to minimize the amount of obvious ‘fliers’ or ‘spikes’ in the data This will reduce the number of Hypotheses that CUBE will generate Save to HS2 format HYPACK Multibeam Training Seminar 4/24/2017

HYCUBE Read Parameters HYPACK Multibeam Training Seminar 4/24/2017

Node Generation Read Parameters Node Spacing: User Defined Distance between depth estimates. (In the Project’s distance units) Originally, you had to have a minimum number of depths (11) in a neighborhood in order to generate a CUBE estimate. Capture Distance: The ‘influence radius’ of a sounding is equal to the depth times the Capture Distance Scale percentage. 5% seems to work well. (e.g. 10’ x 5% = 0.5’) Median Length: (No Longer an Option) The number of depths needed in a neighborhood in order to generate a CUBE estimate. HYCUBE will use 1 sounding, if that’s all that is available. Also used for the CUBE Median Filter (3 = weak; 11 = strong) HYPACK Multibeam Training Seminar 4/24/2017

Disambiguation Method Read Parameters Disambiguation: Method used by CUBE to select a depth hypothesis for a node when multiple hypotheses exist. Prior: Selects the hypothesis represented by the most data points. Likelyhood: Searches for the nearest node with a single depth hypothesis and bases it’s select off that z-value. (Recommended) Posterior: A combination of the above two methods. HYPACK Multibeam Training Seminar 4/24/2017

HYPACK Multibeam Training Seminar New Hypothesis Window in 2011 Version 4/24/2017 HYPACK Multibeam Training Seminar

HYPACK Multibeam Training Seminar Running HYCUBE Select HS2 file (Single file or LOG file) Select Configuration: Sonar Type Vessel Error Model Read Parameters Node Spacing Min/max depth Max angle (optional filters to use) 4/24/2017 HYPACK Multibeam Training Seminar

Sonar Device CUBE Configuration CUBE has error models for some sonars. This information improves the TPU computation. If your sonar is not listed: Select ‘Not Listed’. List of sonars with built-in error models in HYCUBE 4/24/2017 HYPACK Multibeam Training Seminar

Vessel Settings CUBE Configuration CUBE uses the Vessel Settings to assist in the computation of TPU. In HYPACK 2009, the items are populated from the TPU EDITOR. In previous versions, you had to enter your own values each time. 4/24/2017 HYPACK Multibeam Training Seminar

Error Model CUBE Configuration There are two error models that CUBE can use when calculating the TPU. Simple (IHO S-44) Full MBES CUBE will reject depths that have a TPU above the specified Survey Order 4/24/2017 HYPACK Multibeam Training Seminar

HYPACK Multibeam Training Seminar Cube Grid Window Displays CUBE surfaces. Depth Surface Uncertainty Ratio # of Hypotheses per Node New OpenGL improvements. Left-click to select node. 4/24/2017 HYPACK Multibeam Training Seminar

Depth Surface CUBE Grid Window Shows a 3D display of CUBE Depth Surface. Left-click to set cursor position. CUBE Node window updates to show distribution at selected node. Left-Click-and-drag to change viewing angles. Right-click to pan. 4/24/2017 HYPACK Multibeam Training Seminar

Uncertainty Surface CUBE Grid Window Useful for quality control. User can export an XYZ file where ‘z’ is the uncertainty for the depth representing each node. 4/24/2017 HYPACK Multibeam Training Seminar

HYPACK Multibeam Training Seminar Ratio CUBE Grid Window Useful for quality control. The lower the better…. Ratio = 5 – [NS / ( NA – NS )] where NS = # depth samples in selected hypothesis and, NA = # depth samples in all hypotheses. 2 examples: GOOD: 40 depths in selected hypothesis, 10 in alternate, 5 – [40/(50-40)] -> Ratio = 1 BAD: 10 depths in selected hypothesis, 40 in alternate, 5 – [10/(50-10)] -> Ratio = 4.75 4/24/2017 HYPACK Multibeam Training Seminar

Hypothesis Count CUBE Grid Window Shows how many depth estimates are generated at each node. 4/24/2017 HYPACK Multibeam Training Seminar

HYPACK Multibeam Training Seminar CUBE Node Window Displays: Distribution of z-values in the node’s neighborhood. CUBE Hypothesis (selected) with uncertainty boundaries. Modifies: Allows you to select an alternative hypothesis for a CUBE node. Searches: Search for a CUBE node with multiple hypotheses. Select alternative hypothesis. Left-click on the alternate hypothesis to select it. 4/24/2017 HYPACK Multibeam Training Seminar

HYPACK Multibeam Training Seminar Save Options Saves to XYZ file. Z can be: CUBE Depth Estimate CUBE Uncertainty Ratio Hypothesis Count Sounding Nearest CUBE Depth Estimate Adjustment: Optionally adds or subtracts the Uncertainly to/from the CUBE Depth. HYPACK Multibeam Training Seminar 4/24/2017

HYPACK Multibeam Training Seminar Sample CUBE Session Input: HS2 Files How much pre-editing in MBMAX should you do? That’s a good question……. HYPACK Multibeam Training Seminar 4/24/2017

Stats: CUBE Results vs. Reference Surface Mean Difference: 0.02’ = 0.6 cm. Max Difference: 0.45’ = 13.7 cm. 95% Confidence: 0.09’ = 2.7 cm. 4/24/2017 HYPACK Multibeam Training Seminar

Comparison: CUBE vs. Sort Min/Max Green: Check Lines Processed in CUBE. Black: Reference Survey Sorted for Min and Max. The HYCUBE surface usually resembles a smoother median surface. 4/24/2017 HYPACK Multibeam Training Seminar