Prepared in cooperation with the National Oceanic and Atmospheric Administration

National Oceanic and Atmospheric Administration 

Hydrographic Survey Data Used in a U.S. Geological 

Survey Regional Geologic Framework Study Along the 

Delmarva Peninsula

Open-File Report 2014–1262

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the National Oceanic and Atmospheric Administration

National Oceanic and Atmospheric Administration 

Hydrographic Survey Data Used in a U.S. Geological 

Survey Regional Geologic Framework Study Along the 

Delmarva Peninsula

By Elizabeth A. Pendleton, Laura L. Brothers, E. Robert Thieler, William W. Danforth, and Castle E. Parker

Open-File Report 2014–1262

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2015

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Suggested citation:

Pendleton, E.A., Brothers, L.L., Thieler, E.R., Danforth, W.W., and Parker, C.E., 2015, National Oceanic 

and Atmospheric Administration hydrographic survey data used in a U.S. Geological Survey regional 

geologic framework study along the Delmarva Peninsula: U.S. Geological Survey Open-File Report 

2014-1262, 18 p., http://dx.doi.org/10.3133/ofr20141262.

ISSN 2331-1258 (online)
iii

Acknowledgments

We thank David Rodziewicz (National Oceanic and Atmospheric Administration [NOAA] Corps), the National 

Ocean Service hydrographic data manager at the National Geophysical Data Center, Marine Geology and 

Geophysics Division, for providing the Reson raw data files for hydrographic surveys: H11647, H11648, H11649, 

H11872, H11873, H11874, H11992, H12001, H12002, H12003, and H12091. We thank Rebecca T. Quintal of 

Leidos (formerly SAIC) for providing, with NOAA’s permission, Reson data files for hydrographic surveys H12092, 

H12093, H12094, H12160, H12161, H12336, H12337, H12338, and H12339. Both David and Rebecca were 

extremely helpful in communicating information and providing data to aid this effort, and we sincerely wish to thank 

them for their patience and cooperation.

We also wish to thank Anya Duxfield and the Fledermaus software support and development team at Quality 

Positioning Service for their dedication to providing support and solutions to the users of Fledermaus FMGeocoder 

Toolbox software.

Andrea Toran of the U.S. Geological Survey (USGS) provided essential support and guidance during the 

publication of this report. This report also benefited from reviews by Larry Poppe, Jane Denny, and VeeAnn Cross 

(all of the USGS).
iv

Contents

Acknowledgments.......................................................................................................................................................iii

Abstract ...................................................................................................................................................................... 1

Introduction................................................................................................................................................................. 2

Methods...................................................................................................................................................................... 3

Regional Bathymetric Grid ...................................................................................................................................... 3

Regional Multibeam Backscatter Mosaic ................................................................................................................ 3

Summary .................................................................................................................................................................... 4

Selected References .................................................................................................................................................. 4

Figures

1. Map of the Delmarva Peninsula, Delaware, Maryland, and Virginia, showing the 23 hydrographic surveys 

used to create the regional bathymetric grid and backscatter mosaic ........................................................... 8

2. Map showing nine hydrographic surveys along the Delmarva Peninsula, Delaware, Maryland, and Virginia, 

that used Klein sidescan sonar between 2006 and 2009 to produce mosaics along with bathymetric data .. 9

3. Maps of gridded bathymetric data from National Oceanic and Atmospheric Administration survey H12003 

along the Delmarva Peninsula, Delaware, Maryland, and Virginia .............................................................. 10

4. Map of resampled, interpolated bathymetric data from National Oceanic and Atmospheric Administration 

surveys H12003, H12092, H12093, and H12094 along the Delmarva Peninsula, Delaware, Maryland, and 

Virginia......................................................................................................................................................... 11

5. Map showing the interpolated bathymetric data along the Delmarva Peninsula, Delaware, Maryland, and 

Virginia, in a 5-meter–per-pixel grid............................................................................................................. 12

6. Map of National Oceanic and Atmospheric Administration survey H11647 along the Delmarva Peninsula, 

Delaware, Maryland, and Virginia................................................................................................................ 13

7. Map of National Oceanic and Atmospheric Administration survey H12160 along the Delmarva Peninsula, 

Delaware, Maryland, and Virginia................................................................................................................ 14

8. Map showing 2-meter-per-pixel resolution multibeam backscatter images for 20 hydrographic surveys 

along the Delmarva Peninsula, Delaware, Maryland, and Virginia .............................................................. 15

9. Images of acoustic backscatter mosaics from National Oceanic and Atmospheric Administration survey 

H12003 along the Delmarva Peninsula, Delaware, Maryland, and Virginia................................................. 16

Tables

1. National Oceanic and Atmospheric Administration hydrographic surveys along the Delmarva Peninsula, 

Delaware, Maryland, and Virginia, processed for multibeam backscatter.................................................... 17

2. Advantages and disadvantages of multibeam echosounder and sidescan sonar backscatter..................... 18
v

Conversion Factors

International System of Units to Inch/Pound

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

kilometer (km) 0.5400 mile, nautical (nmi) 

Area

square meter (m2) 10.76 square foot (ft2) 

square kilometer (km2) 0.3861 square mile (mi2)

Datum

Vertical coordinate information is referenced to the Mean Lower Low Water (MLLW) tidal datum.

Horizontal coordinate information is referenced to the World Geodetic Coordinate System of 1984 (WGS 84).

Abbreviations

BAG bathymetry attributed grid

FMGT FMGeocoder Toolbox Fledermouse module

GIS geographic information system

GeoPDF georeferenced portable document formation

GeoTIFF georeferenced tagged interface file format

GSF generic sensor format

MBES multibeam echosounders

M/V motor vessel

NOAA National Oceanic and Atmospheric Administration

NOS National Ocean Service

SAIC Science Applications International Corporation

USGS U.S. Geological Survey

1

National Oceanic and Atmospheric Administration 

Hydrographic Survey Data Used in a U.S. Geological 

Survey Regional Geologic Framework Study Along the 

Delmarva Peninsula

By Elizabeth A. Pendleton, 1 Laura L. Brothers,

1 E. Robert Thieler,1 William W. Danforth,1 and Castle E. Parker2

Abstract

The U.S. Geological Survey initiated a research effort in 2014 to define the geologic framework 

of the Delmarva Peninsula inner continental shelf, which included new data collection and assembly of 

relevant extant datasets. Between 2006 and 2011, Science Applications International Corporation, under 

contract to the National Oceanic and Atmospheric Administration National Ocean Service, carried out 

23 hydrographic surveys covering more than 4,100 square kilometers of the continental shelf using 

Reson multibeam echosounders and Klein towed sidescan sonars to update nautical charts along the 

Delmarva Peninsula. Acoustic backscatter data from these instruments are valuable for characterizing 

aspects of shallow geologic framework, including seafloor geology, sediment transport pathways, and 

marine resources. The data cover an area that extends from the entrance of Delaware Bay, Delaware,

south to Parramore Island, Virginia, in water depths of about 3 to 35 meters below mean lower low 

water. Data were collected along lines spaced 40 meters apart, resulting in 40 to 100 percent seafloor 

coverage for multibeam bathymetry. Processed bathymetric data within the Delmarva Peninsula study 

area are available through a National Ocean Service interactive map interface, but towed sidescan data 

products are limited, and multibeam backscatter data products have not been available in the past.

The U.S. Geological Survey obtained raw Reson multibeam data files from Science Applications 

International Corporation and the National Oceanic and Atmospheric Administration for 20 

hydrographic surveys and extracted backscatter data using the Fledermaus Geocoder Toolbox from

Quality Positioning Service. The backscatter mosaics produced by the U.S. Geological Survey for the 

inner continental shelf of the Delmarva Peninsula using National Oceanic and Atmospheric 

Administration data increased regional geophysical surveying efficiency, collaboration among 

government agencies, and the area over which geologic data can be interpreted by the U.S. Geological 

Survey. This report describes the methods by which the backscatter data were extracted and processed 

and includes backscatter mosaics and interpolated bathymetric surfaces.

 1

U.S. Geological Survey

2

National Oceanic and Atmospheric Administration
2

Introduction

In 2014, the U.S. Geological Survey (USGS) began a collaborative project with the University 

of Delaware, the National Park Service, the Mid-Atlantic Coastal Resilience Institute, and the National 

Oceanographic and Atmospheric Administration (NOAA) to define the geologic framework of the 

Delmarva Peninsula coastal system. Geologic mapping of the inner continental shelf combined with 

oceanographic processes data are intended to be used to facilitate effective management of this dynamic 

coastal system as it responds to storms, sea-level rise, and anthropogenic activities. This mapping effort 

builds on recent and ongoing hydrographic, geologic, and ecological studies in the area and represents a 

unique opportunity to construct a geospatial framework around existing datasets and to acquire new data 

to fill knowledge gaps. This report presents an existing hydrographic dataset collected by Science 

Applications International Corporation (SAIC) under contract to NOAA’s National Ocean Service 

(NOS) and reprocessed by the USGS to extract backscatter and generate seamless bathymetric and 

backscatter surfaces for the region. Prior to recent software advances, multibeam backscatter datasets 

were too cumbersome to extract and use. This report describes a technique that uses recently developed 

software to reprocess the NOAA dataset. The dataset as reprocessed by the USGS provides valuable 

baseline geophysical information that enhances our understanding of seafloor geology and sediment 

transport pathways within the Delmarva coastal system.

Between 2006 and 2011, NOAA carried out 23 hydrographic surveys covering more than

4,100 square kilometers of the Atlantic inner shelf adjacent to the Delmarva Peninsula. Reson 

multibeam echosounders (MBESs) and Klein sidescan sonars were used to collect data aboard the motor 

vessel (M/V) Atlantic Surveyor for the purposes of updating nautical charts (fig. 1; table 1). The survey 

area extended from the entrance of Delaware Bay offshore of Cape Henlopen, Delaware, to the south 

past Parramore Island, Virginia, in water depths from about 3 to 35 meters (m) below mean lower low 

water (fig. 1). MBES bathymetry and backscatter were acquired using a Reson Seabat 8101 between 

2006 and 2009 and a Reson Seabat 7125 between 2010 and 2011. Sidescan sonar data were collected 

with a Klein 3000 dual frequency sonar. The Reson MBES bathymetric and backscatter data are the 

focus of this report. Trackline spacing was set at 40 m for all 23 of the hydrographic surveys, producing 

full seafloor coverage in water depths greater than 10 m and between 40 and 100 percent coverage in 

water depths less than 10 m.

NOAA published the processed Reson bathymetry for all 23 hydrographic surveys in 

bathymetry attributed grid (BAG) format files at resolutions from 50 centimeters per pixel to 4 meters

per pixel. Klein sidescan sonar mosaics were published as georeferenced tagged image file formats 

(GeoTIFFs) from three of the surveys and as layers in georeferenced portable document format 

(GeoPDF) maps from six other surveys (fig. 2; table 1). The bathymetric and sidescan data are available 

on the National Geophysical Data Center’s (NGDC) Interactive Mapping Server (IMS) Web interface 

(http://maps.ngdc.noaa.gov/viewers/bathymetry/). Multibeam BAG files were downloaded from the 

IMS for each survey, interpolated to fill gaps, then combined (mosaicked) at 5-meter-per-pixel 

resolution. In order to create a continuous backscatter mosaic for the seafloor in the surveyed area, the 

USGS obtained the raw Reson data in generic sensor format (GSF) from NOAA and SAIC for 20 

surveys to process for backscatter.
3

Methods

Regional Bathymetric Grid

More than 40 BAG files were downloaded from the NGDC’s IMS at resolutions between 

50 centimeters per pixel and 4 meters per pixel. Due to the set 40-m track line spacing, seafloor 

coverage was less than 100 percent in water depths less than 10 m (fig. 3). Each BAG file was imported 

into Quality Positioning Service’s (QPS) Fledermaus software and converted to scientific data [object]

(.sd) format. Individual .sd files within surveys were then merged using the surfacemerge function in 

Fledermaus’s FMCommand utility. The merged .sd files were then interpolated for five iterations using 

the Fledermaus “interpolate surface” function to fill gaps in shallow-water areas. Despite five iterations, 

gaps remain in the regional bathymetric grid across three shoal areas in the vicinity of Chincoteague

Inlet Va., where the M/V Atlantic Surveyor could not survey due to draft restrictions (fig. 4). These gaps 

were left unfilled in order to avoid introducing erroneous depth values through interpolation. Merged, 

interpolated 32-bit GeoTIFFs for each survey were exported from Fledermaus and loaded into Esri 

ArcMap where they were resampled to 5-meter-per-pixel resolution and mosaicked into a single raster 

dataset (fig. 5).

Regional Multibeam Backscatter Mosaic

In 2005, the University of New Hampshire developed GeoCoder software to improve multibeam 

backscatter processing (Rzhanov and others, 2011). GeoCoder backscatter processing algorithms are 

now part of several hydro-industry software packages. In this report, QPS Fledermaus FMGeocoder 

Toolbox (FMGT) version 7.4.1 was used to process all GSF format Reson data obtained from NOAA

and SAIC. The relative ease with which multibeam backscatter can now be processed gives multibeam 

backscatter some advantages over sidescan sonar backscatter. However, the broader swath width of a 

sidescan sonar compared with the swath width of MBES can be a surveying time advantage in areas 

where full multibeam seafloor coverage is not required (table 2).

The survey data obtained from NOAA and SAIC contained only beam-average backscatter data, 

meaning that ‘snippets’ or time series backscatter data were not recorded. Beam-average data can still 

produce high-quality backscatter imagery, especially for regional-scale geologic mapping purposes. 

Geoscientists prefer snippet data, when available, because they offer the full time series of decibel (dB)

values and thus a more dynamic range in a final backscatter mosaic when compared with beam-average 

data. Snippet data files, however, can be prohibitively large to archive because the full dB time series 

results in raw data files that are several times larger than files without snippet data. SAIC did not 

archive multibeam backscatter snippets because NOAA’s charting mission was fulfilled by the 

collection of multibeam bathymetry, including more than 200 percent seafloor coverage with sidescan 

sonar data.

Hydrographic surveys were processed individually in FMGT to allow modification of processing 

parameters among surveys (such as ocean absorption coefficients). In most cases, the data were 

processed as beam-average Reson 8101 or 7125 backscatter data on a per survey basis. The metadata 

included in the Data Download section of this report provide more detailed information on processing 

parameters.

All of the 20 Reson surveys for which GSF data were obtained produced useable backscatter 

mosaics, though there was some variation in mosaic quality. With the help of the software support and 

development team at QPS, issues encountered during processing were resolved. One issue noted in the 
4

Reson 7125 data from 2010 and 2011 was resolved by QPS under a new software release (version 

7.4.1). In general, among the surveys where sidescan sonar mosaics are available for comparison with 

multibeam backscatter mosaics, both the Reson 8101 and the Reson 7125 produced backscatter mosaics 

of quality comparable to the Klein sidescan sonar mosaics (figs. 6 and 7). Some mosaics contain 

banding artifacts from incremental gain changes during acquisition, but the banding does not appear to 

obscure seafloor features in the final 2-meter-per-pixel resolution backscatter mosaics. After satisfactory 

mosaic images for each survey were produced with FMGT, mosaics were exported as 2-meter-per-pixel 

resolution GeoTIFF images (fig. 8). MathWorks’s MATLAB was used to fill gaps between adjacent 

lines in shallow water (less than 8 to 10 m deep) and other small data drop out areas in the mosaics by 

interpolating backscatter values from surrounding pixels to replace pixels with null values using an 

inverse distance-weighted method. Surveys at an average depth greater than 10 m required minimal 

interpolation. More interpolation was required in some of the nearshore surveys where mean water 

depths were less than 10 m and seafloor coverage was less than 100 percent (fig. 9).

Summary

A seamless regional 5-meter-per-pixel bathymetric grid (fig. 5) and 2-meter-per-pixel resolution

backscatter mosaic images (fig. 8) for the inner continental shelf from Cape Henlopen, Delaware, to 

Parramore Island, Virginia, were created from hydrographic survey data collected by Science 

Applications International Corporation and the National Oceanic and Atmospheric Administration 

(NOAA) National Ocean Service (NOS). These data were collected by NOAA at high resolution and 

high density to update navigational charts and identify navigational hazards along the coast of the 

Delmarva Peninsula. The U.S. Geological Survey (USGS) reprocessed and resampled the data to aid a

regional-scale geologic framework study of the Delmarva Peninsula, which aims to facilitate our 

understanding and effective management of this dynamic coastal system as it responds to storms, sealevel rise, and anthropogenic activities.

This study is an example of interagency collaboration and demonstrates that one dataset can 

serve the missions of two agencies. Although NOAA and the USGS often partner to conduct research 

and create geologic data products from hydrographic survey information (for example, Andrews and 

others, 2013; Poppe and others, 2014), this study is unique in that the backscatter data products are 

derived from multibeam echosounder (MBES) data, which have historically been underutilized as a 

geophysical dataset until the availability of software that can efficiently process large volumes of MBES 

backscatter data. This study suggests that similar NOAA datasets could be reprocessed and repurposed 

for geologic investigations in the future. Such collaborations optimize government investments in 

marine research.

Selected References

Andrews, B.D., Chaytor, J.D., ten Brink, U.S., Brothers, D.S., and Gardner, J.V., 2013, Bathymetric 

terrain model of the Atlantic Margin for marine geological investigations: U.S. Geological Survey 

Open-File Report 2012–1266, 11 p., accessed September 12, 2014, at 

http://dx.doi.org/10.3133/ofr20121266.

Hewitt, Anthony, Salisbury, Richard, and Wilson, Jerry, 2010, Using multibeam echosounder 

backscatter to characterize seafloor features—Geocoder processing gives multibeam echosounder 

backscatter an advantage over side scan sonar in producing reliable seafloor maps: Sea Technology, 
5

v. 51, no. 9, accessed July 23, 2014, at http://www.seatechnology.com/features/2010/0910/multibeam_echosounder_backscatter.php.

National Oceanic and Atmospheric Administration, 2006a, Survey H11554—Multibeam and side scan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 06–TR–015, 

13 p., accessed September 12, 2014, at http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-

H12000/H11554/DR/H11554.pdf.

National Oceanic and Atmospheric Administration, 2006b, Survey H11555—Multibeam and side scan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 06–TR–016, 

57 p., accessed September 12, 2014, at http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-

H12000/H11555/DR/H11555.pdf.

National Oceanic and Atmospheric Administration, 2007a, Survey H11650—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 07–TR–011, 

18 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-H12000/H11650/DR/H11650.pdf.

National Oceanic and Atmospheric Administration, 2007b, Survey H11647—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 07–TR–008, 

164 p., accessed September 12, 2014, at http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-

H12000/H11647/DR/H11647.pdf.

National Oceanic and Atmospheric Administration, 2007c, Survey H11648—Multibeam and sidescan 

sonar descriptive report: OPR–D302–KR–07: National Oceanic and Atmospheric Administration 

SAIC Doc. 07–TR–009, 167 p, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-H12000/H11648/DR/H11648.pdf.

National Oceanic and Atmospheric Administration, 2007d, Survey H11649—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 07–TR–010, 

77 p., accessed September 12, 2014, at http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-

H12000/H11649/DR/H11649.pdf.

National Oceanic and Atmospheric Administration, 2008a, Survey H11872—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 09–TR–035, 

34 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-H12000/H11872/DR/H11872.pdf.

National Oceanic and Atmospheric Administration, 2008b, Survey H11873—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 09–TR–043, 

32 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-H12000/H11873/DR/H11873.pdf.

National Oceanic and Atmospheric Administration, 2008c, Survey H11992—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 09–TR–045, 

19 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-H12000/H11992/DR/H11992.pdf.

National Oceanic and Atmospheric Administration, 2008d, Survey H11874—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 09–TR–044, 

24 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H10001-H12000/H11874/DR/H11874.pdf.

National Oceanic and Atmospheric Administration, 2009, Survey H12001—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 10–TR–001, 

20 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12001/DR/H12001.pdf.
6

National Oceanic and Atmospheric Administration, 2010a, Survey H12093—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 11–TR–001, 

35 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12093/DR/H12093.pdf.

National Oceanic and Atmospheric Administration, 2010b, Survey H12094—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 10–TR–040, 

41 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12094/DR/H12094.pdf.

National Oceanic and Atmospheric Administration, 2010c, Survey H12160—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 11–TR–003, 

26 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12161/DR/H12161.pdf.

National Oceanic and Atmospheric Administration, 2010d, Survey H12002—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 10–TR–002, 

74 p., accessed September 12, 2014, at http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-

H14000/H12002/DR/H12002.pdf.

National Oceanic and Atmospheric Administration, 2010e, Survey H12003—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 10–TR–003, 

31 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12003/DR/H12003.pdf.

National Oceanic and Atmospheric Administration, 2010f, Survey H12091—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 10–TR–004, 

26 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12091/DR/H12091.pdf.

National Oceanic and Atmospheric Administration, 2010g, Survey H12092—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 10–TR–030, 

41 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12092/DR/H12092.pdf.

National Oceanic and Atmospheric Administration, 2011a, Survey H12336—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 11–TR–030, 

29 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12336/DR/H12336.pdf.

National Oceanic and Atmospheric Administration, 2011b, Survey H12337—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 12–TR–003, 

29 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12337/DR/H12337.pdf.

National Oceanic and Atmospheric Administration, 2011c, Survey H12339—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 12–TR–005, 

33 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12339/DR/H12339.pdf.

National Oceanic and Atmospheric Administration, 2011d, Survey H12160—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 11–TR–005, 

27 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12160/DR/H12160.pdf.

National Oceanic and Atmospheric Administration, 2011e, Survey H12338—Multibeam and sidescan 

sonar descriptive report: National Oceanic and Atmospheric Administration SAIC Doc. 12–TR–004, 
7

33 p. plus appendixes, accessed September 12, 2014, at

http://surveys.ngdc.noaa.gov/mgg/NOS/coast/H12001-H14000/H12338/DR/H12338.pdf.

Poppe, L.J., McMullen, K.Y., Danforth, W.W., Blankenship, M.A., Clos, A.R., Glomb, K.A., Lewit, 

P.G., Nadeau, M.A., Wood, D.A., and Parker, C.E., 2014, Combined multibeam bathymetry data from 

Rhode Island Sound and Block Island Sound—A regional perspective: U.S. Geological Survey OpenFile Report 2014–1012, DVD-ROM, accessed September 12, 2014, at 

http://dx.doi.org/10.3133/ofr20141012.

Rzhanov, Yuri, Fonseca, Luciano, and Mayer, Larry, 2011, Construction of seafloor thematic maps 

from multibeam acoustic backscatter angular response data: Computers and Geosciences Journal, 

v. 41, p. 181–187. [Also available at http://dx.doi.org/10.1016/j.cageo.2011.09.001.]
8

Figure 1. Map of the Delmarva Peninsula, Delaware, Maryland, and Virginia, showing the 23 hydrographic 

surveys used to create the regional bathymetric grid and backscatter mosaic. The survey boundaries and numbers 

are shown along with the multibeam bathymetric data that were collected simultaneously with backscatter using 

Reson 8101 and Reson 7125 systems. Details of the hydrographic surveys are listed in table 1. MLLW; mean lower 

low water. Not for navigational use.
9

Figure 2. Map showing nine hydrographic surveys along the Delmarva Peninsula, Delaware, Maryland, and 

Virginia, that used Klein sidescan sonar to produce mosaics along with bathymetric data. Details of the 

hydrographic surveys are listed in table 1. Not for navigational use. Other sidescan mosaics may be available by 

request through NOAA.
10

Figure 3. Maps of gridded bathymetric data from National Oceanic and Atmospheric Administration (NOAA) 

survey H12003 along the Delmarva Peninsula, Delaware, Maryland, and Virginia, showing A, a 1-meter-per-pixel 

grid containing data gaps within areas shallower than approximately 10 meters, and B, a 5-meter-per-pixel grid 

generated by the U.S. Geological Survey through interpolation and resampling of the NOAA data for use in regional 

geologic mapping studies. Map location is shown on figure 5. MLLW, mean lower low water. Not for navigational 

use.
11

Figure 4. Map of resampled, interpolated bathymetric data from National Oceanic and Atmospheric 

Administration surveys H12003, H12092, H12093, and H12094 along the Delmarva Peninsula, Delaware, 

Maryland, and Virginia, showing data gaps (black arrows) across the tops of shoals that were not filled in after five 

iterations of nearest neighbor interpolation. These gaps were left unfilled in order to avoid introducing erroneous 

depth values through interpolation. Map location is shown on figure 5. Not for navigational use. MLLW, mean lower 

low water.
12

Figure 5. Map showing the interpolated bathymetric data along the Delmarva Peninsula, Delaware, Maryland, 

and Virginia, in a 5-meter–per-pixel grid. Bathymetric data were merged and small gaps filled between adjacent 

survey lines to create a regional seamless bathymetric grid to use in regional geologic framework studies. Not for 

navigational use. MLLW, mean lower low water.
13

Figure 6. Map of National Oceanic and Atmospheric Administration survey H11647 along the Delmarva 

Peninsula, Delaware, Maryland, and Virginia, showing a backscatter mosaic collected A, with a Klein 3000 

sidescan sonar published as a georeferenced tagged image format file and B, with a Reson 8101multibeam 

echosounder system (MBES) and processed by U.S. Geological Survey. Both sidescan and multibeam backscatter 

data are able to resolve a series of shoreface-attached ridges; however, there appears to be more dynamic range 

in the multibeam data. Some banding artifacts are present in the MBES data. These are thought to be introduced 

by gain changes during acquisition. Location of survey is shown on figure 1.
14

Figure 7. Map of National Oceanic and Atmospheric Administration survey H12160 along the Delmarva 

Peninsula, Delaware, Maryland, and Virginia, showing a backscatter mosaic collected A, with a Klein 3000 

sidescan sonar published as a layer in a georeferenced portable document format map and B, with a Reson 7125 

multibeam system and processed by U.S. Geological Survey. The sidescan sonar data have some nadir artifacts

and data dropouts, which create striping in the mosaic. Multibeam data contain banding artifacts, but overall less 

striping than the sidescan sonar data. Location of survey is shown on figure 1.
15

Figure 8. Map showing 2-meter-per-pixel resolution multibeam backscatter images for 20 hydrographic surveys 

along the Delmarva Peninsula, Delaware, Maryland, and Virginia, collected by Science Applications International 

Corporation for the National Oceanic and Atmospheric Administration and reprocessed by the U.S. Geological 

Survey to create a regional backscatter mosaic for geologic framework investigations. Not for navigational use.
16

Figure 9. Images of acoustic backscatter mosaics from National Oceanic and Atmospheric Administration survey 

H12003 along the Delmarva Peninsula, Delaware, Maryland, and Virginia, A, uninterpolated to show real data gaps 

(in red) between shallow water lines and B, interpolated output from MathWorks MATLAB that removes null-data 

gaps and creates a seamless backscatter image. Map location is shown on figure 5. Not for navigational use.
17

Table 1. National Oceanic and Atmospheric Administration hydrographic surveys along the Delmarva Peninsula, 

Delaware, Maryland, and Virginia, processed for multibeam backscatter. Sidescan sonar mosaics listed as not 

available through the IMS may be available by request through NGDC.

[Hydrographic survey data were processed with FMGeocoder Toolbox of Quality Positioning Service’s Fledermaus. Click on a survey 

number to retrieve the survey descriptive report; descriptive reports are listed in the Selected References section of this report. NGDC, 

National Geophysical Data Center ; IMS, Internet Mapping Server; km, kilometers; km2, square kilometers; GeoTIFF, georeferenced 

tagged interface format file; Geo PDF, georeferenced portable document format]

Survey 

number

Year 

collected

Multibeam 

system

Length of 

trackline, in km Survey area, in km2

Sidescan mosaic 

available on NGDC 

IMS

Included in 

backscatter 

mosaic

Included in regional 

bathymetric grid

H11554 2006 Reson 8101 3,939 155 GeoTIFF No Yes

H11555 2006 Reson 8101 6,035 240 GeoTIFF No Yes

H11647 2007 Reson 8101 3,139 121 No Yes Yes

H11648 2007 Reson 8101 5,065 223 No Yes Yes

H11649 2007 Reson 8101 5,086 200 No Yes Yes

H11650 2007 Reson 8101 3,924 180 GeoTIFF No Yes

H11872 2008 Reson 8101 6,600 263 No Yes Yes

H11873 2008 Reson 8101 5,502 290 No Yes Yes

H11874 2008 Reson 8101 6,320 248 No Yes Yes

H11992 2008 Reson 8101 2,219 142 No Yes Yes

H12001 2009 Reson 7125 1,231 77 No Yes Yes

H12002 2010 Reson 7125 3,745 203 No Yes Yes

H12003 2010 Reson 7125 5,585 220 No Yes Yes

H12091 2010 Reson 7125 3,782 164 No Yes Yes

H12092 2010 Reson 7125 7,014 225 No Yes Yes

H12093 2010 Reson 7125 2,841 182 GeoPDF layer Yes Yes

H12094 2010 Reson 7125 4,996 196 No Yes Yes

H12160 2011 Reson 7125 3,240 127 GeoPDF layer Yes Yes

H12161 2011 Reson 7125 1,883 119 No Yes Yes

H12336 2011 Reson 7125 2,607 103 GeoPDF layer Yes Yes

H12337 2011 Reson 7125 1,862 118 GeoPDF layer Yes Yes

H12338 2011 Reson 7125 4,372 163 GeoPDF layer Yes Yes

H12339 2011 Reson 7125 2,430 154 GeoPDF layer Yes Yes
18

Table 2. Advantages and disadvantages of multibeam echosounder and sidescan sonar backscatter.

[Based on Hewitt and others (2010). Advantages are shown highlighted in green, and disadvantages, in red]

Multibeam echosounder backscatter Sidescan sonar backscatter

Bathymetry and backscatter are collected simultaneous with a multibeam 

echosounder system (MBES), so only one instrument is necessary

A towed sidescan system can introduce significant positioning errors 

associated with cable-out and currents; this may lead to offsets in mosaics 

between adjacent survey lines

Multibeam backscatter can be radiometrically (travel path) and 

geometrically (seafloor topography) corrected because the area of 

insonification is known in three dimensions

Sidescan sonar data can contain offsets and shadows associated with 

features because there is no correction of bathymetry and the seafloor is 

assumed to be flat

Multibeam backscatter range is limited by water depth in the same way that 

multibeam bathymetry is limited; surveying efficiency is not as good with 

an MBES when compared with a sidescan sonar system

The much broader swath width (100 to 200-meter range in shallow water) of 

a sidescan sonar system can greatly increase surveying efficiency for 

shallow water (less than 50 meter) surveys where 100 percent

bathymetric coverage is not needed

With the development of GeoCoder processing algorithms, MBES 

backscatter processing is largely managed by a computer with limited 

time invested by a user

Processing can be time consuming, requiring user input for many processing 

steps including bottom detection, corrections, and positional offsets
For more information concerning this report, contact

Director

Woods Hole Coastal and Marine Science Center

U.S. Geological Survey

384 Woods Hole Road

Quissett Campus

Woods Hole, MA 02543–1598

WHSC_science_director@usgs.gov

Telephone: (508) 548–8700 or (508) 457–2200

or visit our Web site at

http://woodshole.er.usgs.gov/
ISSN 2331

-1258 (online)

http://dx.doi.org/10.3133/ofr20141262

Pendleton and others—Hydrographic Survey Data Used in a U.S. Geological Survey Regional Geologic Framework Study, Delmarva Peninsula —OFR 2014–1262