Brian Calder's research while affiliated with University of New Hampshire and other places
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Publications (96)
The compilation of Electronic Navigational Charts (ENCs) requires significant amount of time, labor-intensive efforts, and cost. Despite the advancements in technology and the various research efforts, generalization tasks are still performed manually or semi-manually with expected human errors. The dramatic increase in the amount of data that is c...
Although much progress has been made in recent years to fully map the world ocean, only approximately 20% is adequately mapped to modern standards. Filling in the remainder must by necessity be a multimodal effort, with traditional ocean mapping technologies such as crewed survey ships with multibeam echosounders being mixed with newer systems such...
When planning for ship navigation or compiling data for a bathymetry map, the navigator or mapper uses many different sources of bathymetry information and navigation hazards. The quality of these sources is inconsistent in general, however, making it challenging to provide a coherent picture for planning. Here, we describe an approach for consiste...
Version of Record now available at http://doi.org/10.1080/01490419.2023.2166173
Supporting data for the submitted paper "Aggregation Methods Using Bathymetry Sources of Differing Subjective Reliabilities for Navigation Mapping"
Conventional techniques for extracting bathymetric soundings from LiDAR point clouds are at best semi-automated and require considerable manual effort. An algorithm that couples a widely used sonar data processing method with a newly developed machine-learning(ML)-based algorithm was evaluated for accuracy and potential operationalisation. Data rep...
Ocean mapping professionals are facing challenges in various areas of the hydrographic workflow. Understanding them can be difficult, as they are many and varied, but essential toward solving them. Some understanding can be reached with studying existing specifications and reports, however a more in-depth knowledge may be acquired directly from pro...
This study describes the geomorphometries of archipelagic aprons on the southern flanks of the French Frigate Shoals and Necker Island edifices on the central Northwest Hawaiian Ridge that are hotspot volcanoes that have been dormant for 10–11 m.y. The archipelagic aprons are related to erosional headwall scarps and gullies on landslide surfaces bu...
To automate extraction of bathymetric soundings from lidar point clouds, two machine learning (ML¹) techniques were combined with a more conventional density-based algorithm. The study area was four data “tiles” near the Florida Keys. The density-based algorithm determined the most likely depth (MLD) for a grid of “estimation nodes” (ENs). Unsuperv...
Shallow-water depth estimates from airborne lidar data might be improved by using sounding attribute data (SAD) and ocean geomorphometry derived from lidar soundings. Moreover, an accurate derivation of geomorphometry would be beneficial to other applications. The SAD examined here included routinely collected variables such as sounding intensity a...
Knowledge of offset vectors from vessel mounted sonars, to systems such as Inertial Measurement Units (IMUs) and Global Navigation Satellite Systems (GNSS) is crucial for accurate ocean mapping applications. Traditional survey methods, such as employing laser scanners or total stations, are used to determine professional vessel offset distances rel...
The goal of this work was to evaluate if routinely collected but seldom used airborne lidar metadata – ‘point attribute data’ (PAD) – analyzed using machine learning/artificial intelligence can improve extraction of shallow-water (less than 20 m) bathymetry from lidar point clouds. Extreme gradient boosting (XGB) models relating PAD to an existing...
The processes controlling advance and retreat of outlet glaciers in fjords draining the Greenland Ice Sheet remain poorly known, undermining assessments of their dynamics and associated sea-level rise in a warming climate. Mass loss of the Greenland Ice Sheet has increased six-fold over the last four decades, with discharge and melt from outlet gla...
Depth areas are utilized by the Electronic Chart Display and Information Systems (ECDIS) along with the vessel's characteristics (e.g., draft, squat) and other situational information (e.g., tides) for separating safe areas from those unsafe to navigate. Any error in their compilation is carried over to the analysis performed in the ECDIS. As a res...
Navigational charts contain a combination of geospatial information of varying quality collected at different times using various techniques. Bathymetric data quality is mainly encoded in electronic charts with the Category of Zones of Confidence (CATZOC). CATZOC provides information about the horizontal and vertical uncertainty of depth informatio...
Charted bathymetry encompasses the cartographer's effort to accurately describe submarine topography based on the source information. A key factor in the selection process is that, at any location, the charted features do not give a false impression that the water depth is deeper than it actually is. Our research work focused on development of an a...
More than 844,000 km2 of the northern Line Islands Ridge mapped with multibeam bathymetry and backscatter provide unprecedented views of the geomorphology of this isolated area in the central equatorial Pacific Ocean. A compilation of all available multibeam data in the area reveals six extensive submarine dendritic channel systems that encompass a...
The Electronic Navigational Chart (ENC) consists of point, line, and area features compiled following the node-chain topological model. To ensure that the topological structure is valid, the International Hydrographic Organization (IHO) has developed a number of checks defined in Publication S-58. Many of the checks deal with the vertical component...
Data quality is visualized in ECDIS as an additional layer with symbols using a rating system of stars: six to two stars for the best to lowest quality data and “U” for unassessed data. This work presents an alternative methodology for consideration by the IHO Data Quality Working Group members.
Presentation of an improved method for the visualization of zones of confidence (ZOC) and quality of bathymetric data (QoBD) on ECDIS.
Marine Volunteered Geographic Information (informally “crowdsourced bathymetry”) has raised much interest within the authoritative hydrographic community as a means to cheaply gather information to satisfy chart updating requirements. So far, however, a routine path to the official chart has been rare, mainly due to lack of calibration and other me...
Most navigational charts are an amalgamation of geospatial information of varying quality collected using different techniques at different times. Data collected with high resolution multi-beam echo sounders or lidar systems may co-exist on the chart with data collected with lead-line as far back as the 18th century. Data quality on charts is curre...
The compilation of nautical charts comprises a number of tasks that are often monotonous, time consuming, and, as such, prone to human error. A long-term goal of the hydrographic community has thus been the automation of the process due to the unquestionable advantages of automation to the accuracy, reliability, and consistency of products for a re...
Modern ocean mapping relies heavily on complex algorithms that may strongly affect the reported outputs (e.g., gridded bathymetry, acoustic mosaics). When implemented in commercial software, these algorithms usually cannot be directly examined, and thus represent black boxes.
To ease the understanding of existing algorithms and the creation of bet...
The nautical chart is one of the fundamental tools in navigation used by mariners to plan and safely execute voyages. Its compilation follows strict cartographic constraints with the most prominent being that of the safety. Thereby, the cartographer is called to make the selection of the bathymetric information for portrayal on charts in a way that...
Depth curves and charted soundings are two structural components of nautical charts, both derived from a more detailed dataset through generalization. Once depth curves are generated, the cartographer makes a selection of soundings that complements the depth curves and other features carrying bathymetric information in the adequate representation o...
Abstract: When planning for ship navigation or compiling data for a bathymetry map, the navigator or mapper use many different sources of bathymetry information and navigation hazards. Sources include electronic charts at different scales, gridded bathymetry of different ages and quality, special purpose vector products, sonar data, crowdsourced da...
A method for partitioning a large computation task (direct, variable resolution bathymetric grid construction from raw observations) into thread-parallel code is described. Based on the data density estimated for the first pass of the CHRT algorithm, this algorithm statically partitions the estimation task into spatially distinct blocks of approxim...
An objective measurement of the bathymetric uncertainty introduced by sonar bottom detection has been proposed (Lurton and Augustin, 2009) to overcome the sonar-specific heuristic solutions proposed by constructors. This approach pairs each sounding with an estimation of sonar detection uncertainty (SDU) based on the width of the signal envelope (a...
The selection of soundings to be shown on nautical charts is one of the most important and complicated tasks in nautical cartography. From the vast number of source soundings the cartographer is called to select all those important for the safety of navigation and to verify the “shoal biased” pattern of selection against the source soundings. A lon...
The uncertainty of a scalar field is essential structuring information for any estimation problem. Establishing the uncertainty in a dense gridded product from sparse or random uncertainty-attributed input data is not, however, routine. This manuscript develops an equation that propagates the uncertainty of individual observations, arbitrarily dist...
A new algorithm for data-adaptive, large-scale, computationally efficient estimation of bathymetry is proposed. The algorithm uses a first pass over the observations to construct a spatially varying estimate of data density, which is then used to predict achievable estimate sample spacing for robust depth estimation across the area of interest. A l...
The review of hydrographic and cartographic data sets is still too often based on tedious and error-prone manual actions; however, these same characteristics make the work suitable for automation. As such, a software suite of task-specific solutions was developed to support the reviewer. The specific application of these tools to NOAA Coast Survey...
A bathymetric terrain model of the Atlantic margin covering almost 725,000 square kilometers of sea floor from the New England Seamounts in the north to the Blake Basin in the south is compiled from existing multibeam bathymetric data for marine geological investigations. Although other terrain models of the same area are extant, they are produced...
Previously unknown features in Hatteras Transverse Canyon and environs were recently mapped during multibeam surveys of almost the entire eastern U.S. Atlantic continental margin. The newly identified features include (1) extensive landslide scarps on the walls of Hatteras Transverse and Hatteras Canyons, (2) an area of multiple landslide deposits...
A detection methodology for marine debris presence after a natural disaster is described. The methodology is based both on a predictive model and a Bayesian hierarchical spatial method.
The chosen fusion approach relies on auto-logistic regression to weight the outputs of multiple target detection algorithms, as well as to capture the intrinsic pro...
Current methods for representing uncertainty in hydrographic products typically describe the type or completeness of data collected, but not the risk of transit or certainty about the data presented. This paper proposes a model for risk based on the background information, own-ship information, and how much is unknown about the area. Based on a mod...
Tidally-referenced shoreline data serve a multitude of purposes, ranging from nautical charting, to coastal change analysis, wetland migration studies, coastal planning, resource management and emergency management. To assess the suitability of the shoreline for a particular application, end users require reliable estimates of the uncertainty in th...
HUDDL is a data description language, written in XML, designed to simplify and standardize the description of hydrographic data files. In addition to providing a standard way to communicate a data format specification between manufacturer and user, in computer-readable format, HUDDL descriptions can also be used to automatically generate both docum...
Since many of the attempts to introduce a universal hydrographic data format have failed or have been only partially successful, a different approach is proposed. Our solution is the Hydrographic Universal Data Description Language (HUDDL), a descriptive XML-based language that permits the creation of a standardized description of (past, present, a...
A study of sound propagation over a submarine canyon northeast of Taiwan was made using mobile acoustic sources during a joint ocean acoustic and physical oceanographic experiment in 2009. The acoustic signal levels (equivalently, transmission losses) are reported here, and numerical models of 3-D sound propagation are employed to explain the under...
Attempting to assess the risk of a release from a potentially polluting marine site (PPMS) can be a very subjective process. The Marine Site Risk Index (MaSiRI) is designed to provide a more objective approach to this process by adopting a table-based evaluation scheme, while still allowing for the inevitable unknown conditions by including a subje...
HMS Challenger made the first sounding of Challenger Deep in 1875 of 8184 m. Many have since claimed depths deeper than Challenger's 8184 m, but few have provided details of how the determination was made. In 2010, the Mariana Trench was mapped with a Kongsberg Maritime EM122 multibeam echosounder and recorded the deepest sounding of 10,984 ± 25 m...
There is currently great interest in lidar surveys of salt marshes to support coastal management and decision making. However, vertical uncertainty of lidar elevations is generally higher in salt marshes than in upland areas, and it can be difficult to empirically quantify due to the challenges of obtaining ground control in marshes. Assuming that...
Necker Ridge is an enigmatic 650-km long, narrow, linear aseismic bathymetric feature that rises 2500 to 3000 m above the abyssal seafloor south of the Hawaiian Ridge. The ridge is the largest of a series of aseismic ridges that emanate from the eastern side of the Mid-Pacific Mountains outward towards the northeast. The trend of Necker Ridge is at...
An increasing availability of geospatial marine
data provides an opportunity for hydrographic agencies to
contribute to the identification of potentially polluting
marine sites (PPMS). This new acronym has been created
not only to refer to shipwrecks of modern vessels, but also
for other types of marine sites such as dumping areas,
pipelines, etc....
The method described attempts to remotely identify the shape of an anthropogenic object, such as a wreck of a modern vessel, using reflectivity data from Multi-Beam Echosounder (MBES) systems. In the beam domain, the backscatter strength values - geometrically and radiometrically corrected - are used to extract a large number of Gray Level Co-occur...
Ship noise data reveal an intensification of the near-surface sound field over a submarine canyon. Numerical modeling of sound propagation is used to study the effect. The noise data were collected during an ocean acoustic and physical oceanography experiment northeast of Taiwan in 2009. In situ measurements of water sound-speed profiles and a data...
The National Oceanic and Atmospheric Administration's (NOAA) National Geodetic Survey (NGS) is mandated to map the national shoreline, which is depicted on NOAA nautical charts, serves as an important source in determining territorial limits, and is widely used in various coastal science and management applications. The National Geodetic Survey's p...
This document describes data, sensors, and other useful information pertaining to the ONR sponsored QPE field program to quantify, predict and exploit uncertainty in observations and prediction of sound propagation. This experiment was a joint operation between Taiwanese and U.S. researchers to measure and assess uncertainty of predictions of acous...
This study presents and compares two new methods of assessing the uncertainty of lidar-derived National Shoreline mapped by NOAA’s National Geodetic Survey: an empirical (ground-based) approach and a stochastic (Monte Carlo) approach.
This study's focus is on the horizontal and vertical uncertainties associated with ALB measurements due to scattering through the water column. A lidar simulator was constructed and we present its design and preliminary results. OCIS codes: (280.3640) Lidar; (010.4458); Oceanic scattering (120.3620); Optical standards and testing; (120.5820) Scatte...
For the United States, the greatest opportunity for an extended continental shelf under UNCLOS is in the ice-covered regions of the Arctic north of Alaska. Since 2003, CCOM/JHC has been using the icebreaker Healy equipped with a multibeam echosounder, chirp subbottom profiler, and dredges, to map and sample the region of Chukchi Borderland and Alph...
a b s t r a c t Acoustic backscatter mosaics derived from multibeam and sidescan sonars are often used to estimate seafloor type and composition, which are important parameters in the description of benthic habitats. However, due to limitations of the mosaicking technique, backscatter mosaics are restricted in their capacity to unambiguously discri...
The long-term goal of the Quantifying, Predicting and Exploiting Uncertainty DRI is to understand and exploit (if possible) the fundamental acoustic, oceanographic, bathymetric and geoacoustic uncertainties of the tactical naval environment, and demonstrate how they may be exploited tactically or strategically in an Exercise Area. Focussing on the...
Vast amounts of new multi-beam bathymetry and associated acoustic backscatter are being collected to support potential US extended continental shelf claims under Article 76 of the UN Convention on the Law of the Sea. The new data have been and are continuing to be collected from US continental and insular margins. The processed bathymetry and backs...
In this paper, we describe an algorithm built on top of a precision time protocol (PTP) implementation that allows for synchronization, syntonization and absolute time referencing to coordinated universal time (UTC), including the estimation of timestamp uncertainty. We call this the software grandmaster (SWGM) algorithm, since it provides similar...
Four drowned shelf-edge delta complexes, two drowned shelf deltas, three drowned barrier islands, large areas of “hardground”, and fields of bedforms on the mid and outer continental shelf and uppermost slope north of the head of De Soto Canyon, NE Gulf of Mexico were mapped with high-resolution multibeam echosounder. Deltas formed not during the l...
The long-term goal of the RIPPLES DRI is to develop the ability to predict the geometry and evolution of seafloor morphology and in particular the presence or absence of ripples which have been shown to affect the sub-seafloor penetration of acoustic energy. Specific goals are to: (1) Measure and model ripple morphology and gradients on scales rang...
A series of experiments were conducted to adjust and normalize the acoustic backscatter acquired by Reson 8111 and 8160 systems. The dependency of the backscatter on the receiver gain, transmit power, pulse width and acquisition mode was analyzed. Empirical beam patterns are calculated as the difference between the backscatter measured by the sonar...
In any geologic application, noisy data are sources of consternation for researchers, inhibiting interpretability and marring images with unsightly and unrealistic artifacts. Filtering is the typical solution to dealing with noisy data. However, filtering commonly suffers from ad hoc (i.e., uncalibrated, ungoverned) application. We present here an...
As the international hydrographic community continues to address the question of irreducible uncertainty in modern surveys, a similar question must be asked of archived vertical beam echosounder (VBES) and leadline data sets. The Office of Naval Research funded STRATAFORM project surveyed an area of the New Jersey shelf around 39 $^circ$ 12' N 72 $...
Article 76 of the UN Convention on the Law of the Sea (UNCLOS) outlines
a series of criteria that may allow a coastal state to extend its legal
jurisdiction beyond the EEZ. The mapping required to support an UNCLOS
submission generates datasets useful to a wide spectrum of disciplines;
the new maps will provide a new framework for the next generati...
Kevin LePage (Naval Research Laboratory, Washington, DC), Robert I. Odom (University of Washington, Applied Physics Laboratory), Irina Overeem, James Syvitski (University of Colorado, INSTAAR, Boulder, CO) and Lincoln Pratson (Duke University, Durham, NC). The weakest link in performance prediction for naval systems operating in coastal regions is...
Multibeam bathymetry and 3.5-kHz sub-bottom profiler data collected from the US icebreaker Healy in 2003 provide convincing evidence for grounded ice on the Chukchi Borderland off the northern Alaskan margin, Arctic Ocean. The data show parallel, glacially induced seafloor scours, or grooves, and intervening ridges that reach widths of 1000 m (rim...
A high-resolution multibeam survey of the northwest Florida shelf mapped six relict shelf-edge deltas, each with a drowned barrier–island system developed on its south and southwestern rims. The deltas appear to have formed during periods of sea-level stasis that occurred between 58,000 and 28,000 years ago. The barrier islands formed on the deltas...
The acoustic backscatter acquired by multibeam and sidescan sonars carries important information about the seafloor morphology and physical properties, providing valuable data to aid the difficult task of seafloor characterization, and important auxiliary information for a bathymetric survey. One necessary step towards this characterization is the...
The Kauai Experiment was conducted from June 24 to July 9, 2003 to provide a comprehensive study of acoustic propagation in the 8–50 kHz band for diverse applications. Particular sub‐projects were incorporated in the overall experiment 1) to study the basic propagation physics of forward‐scattered high‐frequency (HF) signals including time/angle va...
We describe an experiment designed to determine the time required to process Multibeam Echosounder (MBES) data using the CUBE (Combined Uncertainty and Bathymetry Estimator) [Calder & Mayer, 2003; Calder, 2003] and Navigation Surface [Smith et al., 2002; Smith, 2003] algorithms. We collected data for a small (22.3×10 6 soundings) survey in Valdez N...
Historically, archaeological investigations use sidescan sonar and
marine magnetometers as initial search tools. Targets are then examined
through direct observation by divers, video, or photographs.
Magnetometers can demonstrate the presence, absence, and relative
susceptibility of ferrous objects but provide little indication of the
nature of the...
[1] Multibeam echosounders (MBES) are currently the best way to determine the bathymetry of large regions of the seabed with high accuracy. They are becoming the standard instrument for hydrographic surveying and are also used in geological studies, mineral exploration and scientific investigation of the earth's crustal deformations and life cycle....
This paper presents the CUBE (Combined Uncertainty and Bathymetry Estimator) algorithm. Our aim is to take advantage of statistical redundancy in dense Multibeam Echosounder data to identify outliers while tracking the uncertainty associated with the estimates that we make of the true depth in the survey area. We recognize that a completely automat...