Importing Bathymetric Datasets: Difference between revisions

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* NOAA – Offshore datasets
* NOAA – Offshore datasets
* LIDAR – Shoreline and nearshore (important for structure resolution)
* LIDAR – Shoreline and nearshore (important for structure resolution)
* Channel
* Channel


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[[Image:NewOrleansDataset 1.png|400px]]
[[Image:NewOrleansDataset 1.png|400px]]
[[Image:NewOrleansDataset 2.png|200px]]
[[Image:NewOrleansDataset 2.png|200px]]


= '''Common Spatial Reference Datum & Vertical Datum''' =
= '''Common Spatial Reference Datum & Vertical Datum''' =
 
[[Image:NewOrleansDataset 3.png|350px]]
[[Image:NewOrleansDataset 52.png|350px]]
[[Image:NewOrleansDataset 52.png|350px]]
[[Image:NewOrleansDataset 53.png|350px]]
[[Image:NewOrleansDataset 53.png|350px]]


[[Image:NewOrleansDataset 3.png|350px]]


[[Image:NewOrleansDataset 4.png|350px]]
[[Image:NewOrleansDataset 4.png|350px]]


= '''Tides and Currents (NOAA)'''  =
= '''Tides and Currents (NOAA)'''  =
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[[Image:NewOrleansDataset 13.png|400px]]
[[Image:NewOrleansDataset 13.png|400px]]
[[Image:NewOrleansDataset 15.png|400px]]
[[Image:NewOrleansDataset 15.png|400px]]
[[Image:NewOrleansDataset 54.png|400px]]
[[Image:NewOrleansDataset 54.png|400px]]


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[[Image:NewOrleansDataset 16.png|400px]]
[[Image:NewOrleansDataset 16.png|400px]]        [[Image:NewOrleansDataset 17.png|400px]]


[[Image:NewOrleansDataset 17.png|400px]]


[[Image:NewOrleansDataset 18.png|400px]]


[[Image:NewOrleansDataset 19.png|400px]]
[[Image:NewOrleansDataset 18.png|400px]]            [[Image:NewOrleansDataset 19.png|400px]]


 
= '''NJ DEP Channel Surveys''' =
= '''NJ DEP Channel Surveys''' =
[[Image:NewOrleansDataset 20.png|400px]]
[[Image:NewOrleansDataset 20.png|400px]]

Latest revision as of 19:43, 9 August 2023


Multiple Bathymetric Datasets

Limited bay bathymetry

  • NOAA – Offshore datasets
  • LIDAR – Shoreline and nearshore (important for structure resolution)
  • Channel

NJ State maintains north channel and north bay channel

Federally maintained entrance and south channel (15 years)

  • NAN-supported field data collection

Included bathymetry of the backbay (Spring High Tide)

NewOrleansDataset 1.png NewOrleansDataset 2.png

Common Spatial Reference Datum & Vertical Datum

NewOrleansDataset 3.png NewOrleansDataset 52.png NewOrleansDataset 53.png


NewOrleansDataset 4.png

Tides and Currents (NOAA)

https://tidesandcurrents.noaa.gov/

NewOrleansDataset 5.png

NewOrleansDataset 6.png

NewOrleansDataset 7.png

Vertical Datum Conversions

NewOrleansDataset 54.png


NewOrleansDataset 8.png


Prep for the Coastal Modeling System

  • Based off of a Cartesian grid
  • Planar coordinate system
  • Model computation is in metric and depths are positive from zero (elevations are flipped)
  • Grid is generated based off of a single bathymetry file stored in SMS scatterset file format
  • Vertical datum is not specified and is assumed local
  • The boundary condition forcing (tidal) must be in the same datum as the bathymetry
  • Typically modeling grids are brought to a mean datum such as mean sea level (msl) or mean tide level (mtl)
  • This requires that all datasets are brought in to unified projection, datum, and units
  • Shark River Inlet bathymetry will be converted to State Plane horizontal coordinates in meters with the vertical datum set to MSL in meters


Reprojecting Coordinates and Changing Datums

NewOrleansDataset 9.png

Object Projection tells SMS what the coordinates are to be project in. This can modify the location that SMS will display the dataset. Checking “Specify” Project Projection is how coordinates are converted to a different projection and vertical datum.


Converting Elevations to Depths (CMS Requirement)

NewOrleansDataset 10.png

Data Transform Can adjust scatterset data by scaling, translating (adding/subtracting), or rotating horizontal or veritcal

NewOrleansDataset 11.png

Select Depths Elevations Flips negative elevations to positive depths. Necessary for CMS model calculation.


NAN Channel Surveys

NewOrleansDataset 12.png


  • Horizontal Datum:

State Plane NAD27 New Jersey 2900 (ft)

  • Vertical Datum:

MLW (ft) – COE Datum (not local NOAA benchmark)


Conversions

NewOrleansDataset 8.png


NAN Channel Surveys Extended in to Bay

NewOrleansDataset 13.png NewOrleansDataset 15.png NewOrleansDataset 54.png

  • Horizontal Datum:

State Plane NAD27 New Jersey 2900 (ft)

  • Vertical Datum:

MLW (ft) – COE Datum (not local NOAA benchmark)

Dataset Calculator

NewOrleansDataset 16.png NewOrleansDataset 17.png


NewOrleansDataset 18.png NewOrleansDataset 19.png

NJ DEP Channel Surveys

NewOrleansDataset 20.png

  • XYZ pulled out of drawing and changed to ascii format

NewOrleansDataset 21.png

Provided conversion from local datum to NAVD88: MLW à NAVD88 + 2.41 ft (0.735 m) MLW à MSL + 2.17 ft (0.661 m)


Field Data Collection – Multibeam Bay Bathymetry (August 2009)

Horizontal Datum: State Plane NAD83 New Jersey 2900 (m) Vertical Datum: NAVD88 (m)


NewOrleansDataset 22.png


LIDAR

NewOrleansDataset 23.png

  • Files are emailed in separate sections from the NOAA CSC Archive
  • Typically several to 10s of files that are 5 - 100 mb in size
  • Compiling takes time
  • Points have been sampled/filtered and cropped to area of interest
  • Horizontal Datum:

State Plane NAD83 New Jersey 2900 (ft) Vertical Datum: NAVD88 (ft)


Coastal Relief Model (DTM/DEM)

NewOrleansDataset 24.png

NewOrleansDataset 25.png

NewOrleansDataset 26.png

NewOrleansDataset 27.png

  • Generate a 3 sec (pt/3rd second) grid

Coastal Relief Model

NewOrleansDataset 28.png

  • Horizontal Datum:

Geographic NAD83

  • Vertical Datum:

MSL (m) – Not accurate for shallow bathymetry (used for offshore)


Extra Bathymetry

NewOrleansDataset 29.png

  • Convert shoreline shapefile in SMS
  • Horizontal Datum:

State Plane NAD83 New Jersey 2900 (ft)

NewOrleansDataset 30.png

  • Added extra bay contour (set to -0.75 m)


Convert a Shapefile to Map

NewOrleansDataset 31.png

  • Drag and drop the shapefile (.shp)

NewOrleansDataset 32.png

  • Highlight all Coastline Mapping – Shapes and Feature Objects

NewOrleansDataset 33.png

  • Turn off GIS Data Arcs generated where GIS polylines

Convert a Map to Scatter

NewOrleansDataset 34.png

  • Highlight all Arcs, Rt-Click Redistribute Vertices Specified Spacing (spacing in spatial coordinates)

NewOrleansDataset 35.png

  • Feature Objects Map à Scatter Include all feature points and vertices (vertices spacing was set to 10)

NewOrleansDataset 36.png

NewOrleansDataset 37.png

NewOrleansDataset 38.png

  • Modify as necessary (i.e. remove entrance channel shoreline because it is old seawall and jetty configuration – LIDAR used here)


Create a Contour Polyline in the Map Module

File:NewOrleansDataset 39.png

Select Default Coverage under Map Data

  • Type à Generic à Mapping/Observation/Shoals

NewOrleansDataset 40.png

  • Draw arcs (polylines) feature with tool

NewOrleansDataset 41.png

  • Select arcs and convert the z elevation to the desired contour elevation


Create Scatterset Points from Map Data

NewOrleansDataset 42.png

  • Select arcs to redistribute the spacing of vertices Feature Objects à Redistribute Vertices Specify Spacing based on horizontal coordinate system units (metric in this case)

NewOrleansDataset 43.png

  • Feature Objects à Map>Scatter Include Feature Pts and vertices and the Arc Elevations

NewOrleansDataset 44.png

NewOrleansDataset 45.png

NewOrleansDataset 46.png


All Files Referenced to Same Horizontal and Vertical Datum

NewOrleansDataset 47.png

NewOrleansDataset 48.png

  • Delete unnecessary data points (check alignment and elevations in overlapping datasets)


Merging Scattersets

NewOrleansDataset 49.png

NewOrleansDataset 50.png

NewOrleansDataset 51.png

  • Merging all scattersets will integrate all points. Overlapping areas of scattersets should either be deleted, or use a separate method of merging (by prioritizing using triangles).


Surface-water Modeling System (SMS)

Questions?

Tanya Beck Tanya.m.beck@usace.army.mil

Or

Mitch Brown Mitchell.e.brown@usace.army.mil

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