1. Pennsylvania State University MGIS Program Advisor: Karen Schuckman
An Analysis of the Survey Decay Term in NOAA's Hydrographic Health Model Using Historic Bathymetric Datasets Nicholas Morgan
Pennsylvania State University
MGIS Program
Advisor: Karen Schuckman

2. What is the Hydrographic Health Model?
Risk based gap analysis
Geospatial Data Driven
Likelihood Parameters (risk)
Consequence Parameters (risk)
Desired Survey Score (gap)
Present Survey Score (gap)
Initial Survey Score (CATZOC)
Decay Function
Change Agents
Fandel et al., 2017

3. The Depreciation Coefficient (The Decay Term)
Fandel et al., 2017
Exponential Decay Function
Inputs are raster files that provide spatially varying change agents
Output is Present Survey Score as a function of time
The base function’s curve:
CATZOC A -> B in 10 years
CATZOC A -> C in 55 years
Single change agent set to max (5), other two set to min (1)
Requires Decay factor of 0.022/4

4. Question: Proposed Solution:
How Does the Decay Term Compare to Real Life?
Further the work of Fandel et al. US Hydro 2017
Proposed Solution:
Attempt to assess real data by comparing historic Hydrographic Smooth Sheet data with modern Bathymetric Attributed Grids

5. Methodology: Identify suitable subject area
Must be an area with large set of historic surveys over past 100 years
Sandy/loose sediment bottom type (consistent with seafloor type in mind when developing HHM)
Perform differencing of historic soundings with modern BAGs (ArcGIS)
Generate basic statistics to describe results as a function of time (is the amount of change related to time?)
Attempt to identify when transitions occur from CATZOC A to B and CATZOC B to C (real world “anchor points”)

6. Data: NECI Bathymetric Data Viewer

7. Data: Modern BAGs (24 surveys from 2003-2012)
1m and 4m resolution. Did not attempt to use BAGs with 50cm resolution
Some BAGs had coordinate system issues after and were not used
NAD83, MLLW
Historic HSSs (24 surveys from )
ASCII XYZ file format

8. Data: Historic HSSs
~1M soundings at various densities

9. Data: Modern BAGs
Full Coverage and Set Line Spacing

10. Process: Part 1 Depth Differencing

11. Process: Part 2 CATZOC Accuracy Thresholds Calculation

12. Final Data Product: ~160,000 sounding comparisons
49 Different DETLA_T values

13. Results:

14. Results:

15. Results:
For DELTA_T with >500 comparisons

16. Considerations: Not factoring in propagated uncertainty
Data bias to frequently surveyed areas
Also tend to be more dynamic seafloors
Difficulty accounting for Human Debris
One, two , and three sigma do not capture extreme outliers

17. Conclusions: Unable to definitively define “anchor points”
Need a more focused approach with homogenous environment
Balance between sample size and subject area size
Further work to compare model results for same subject area

18. Acknowledgements Karen Schuckman, Advisor Penn State MGIS Program
NOAA’s Office of Coast Survey for Historical Information
Corey Allen, Mike Gonsalves, Christy Fandel Office of Coast Survey, Hydrographic Surveys Division

19. References
ESRI ArcGIS Desktop: Release Redlands, CA: Environmental Systems Research Institute.
Fandel, C., Gonsalves, M., Keown, P., Allen, C., Hick, L., and Gallagher, B. (2017). Hydrographic Health: A National Overview [PowerPoint slides]. Retrieved via through personal communication.
International Hydrographic Organization. (2014). IHO Transfer Standard for Digital Hydrographic Data (IHO Publication S-57, Edition 3.1, Supplement No. 3). Retrieved from
National Oceanic and Atmospheric Administration, National Centers for Environmental Information (2019). Bathymetric Data Viewer. Retrieved from
National Oceanic and Atmospheric Administration, Office of Coast Survey (2012). NOAA Hydrographic Survey Priorities Edition. Retrieved from
National Oceanic and Atmospheric Administration, Office of Coast Survey (2017). History of Coast Survey. Retrieved July 12, 2018 from
National Oceanic and Atmospheric Administration, Office of General Council (2017). United States is an Ocean Nation. Retrieved March 12, from
United Nations, Oceans and Laws of the Sea (1982). Laws of the Sea, Part V, Article 57. Retrieved March 12, 2019 from