1. A New Approach for Applying Bathymetry to Nautical Charts
Noel Dyer
Cartographer, NOAA

2. Current Electronic Chart Suite

3. Re-scheme Plan

4. Reducing ENC Scales Reducing unique scales from 131 to 10
Re-compilation of data to fit new scales
Applying new incoming data directly to the updated scale

5. Recommended depth contours per scale band
Standard Scale (rounded)
Width
Height
Band 1
1:5,120,000
38.4
100, ,…
1:2,560,000
19.2
50,100,150,200,…
Band 2
1:1,280,000
9.6
1:640,000
4.8
,50,100,150,200,…
Band 3
1:320,000
2.4
20,30,50,100,150,200,…
1:160,000
1.2
10, ,20,30,50,100,150,200,…
Band 4
1:80,000
0.6
5, , ,20,30,50,100,150,200,…
1:40,000
0.3
2, , , ,20,30,50,100,150,200,…
Band 5
1:20,000
0.15
2, , ,10,15,20,30,50,100,150,200,…
1:10,000
0.075
2,3,4,5,6,7,8,10,15,20,30,50,100,150,200,…
Recommended depth contours per scale band
IHO S-4 (B-411)

6. Hydrographic Survey Data
MCD receives survey data in grid format
Cleaned for anomalies, set to horizontal/vertical datum prior to arrival
Sunset of H-Cell
(USGS)

7. Bathymetric Attributed Grid
Depth
Uncertainty

8. Automating Cartographic Processing
Tool developed to support the creation of new re- schemed ENC chart products
Creates depth areas, contours and soundings at scale from input raster surface (BAG file)

9. Simplified Workflow
Creates depth areas through series of geo-processing tasks
Raster to polygon, dissolve, buffer, aggregate, smooth, clip
Creates contours using the intersections of adjacent depth areas
Creates soundings by converting the input raster to point features
Also creates a thinned version for display purposes

10. Automating Cartographic Processing
Depth Range

11. Another Example

12. Limitations
Depth Range

13. Conclusions
Tool developed to derive depth areas, contours, and selected soundings from gridded bathymetry data
Positive feedback from MCD cartographers
Efficiency and support for cartographic judgements
May still require manual adjustments
Improvements in development

14. Thank you for your time! Questions?