20 Mar 2023

Reception of Automatic Identification System (AIS) Message 21 from US Army Corps of Engineer AIS sites along the Upper Mississippi River, Mile 0 to 301

Purpose: The purpose of this study was to map the on-vessel receipt of message 21 broadcasts from shoreside Automatic Identification System (AIS) sites. Message 21 is one of 27 different AIS messages, and it is used to provide information about real and virtual aids to navigation (AtoNs). Virtual AtoNs are broadcast to warn mariners of hazards like temporary construction zones or submerged debris that may not be marked with a physical buoy. In this study, message 21 was broadcast from different shore-based AIS transceiver sites along the river. Equipment onboard the patrol vessel Pathfinder was monitored for receipt of message 21 during patrols on the Mississippi River that ranged from Lock and Dam (L&D) 22 to Cairo, Illinois, with the confluence of the Ohio River. The Pathfinder is owned by the US Army Corps of Engineers (USACE) and is based out of the St. Louis District (MVS). Understanding where vessels receive, or do not receive, message 21 has important implications for maritime safety in this heavily traveled portion of the inland waterway system.

9 Mar 2023

Automatic Identification System (AIS) Data Case Study: Vessel Traffic through the Yaquina Bay Breakwater at Newport, Oregon

Abstract: The navigation staff at US Army Corps of Engineers (USACE) Portland District (NWP) asked for information on vessel transits through the two existing openings in the breakwater on the north side of Yaquina Bay in Newport, Oregon. Currently, no authorized federal channel passes through the breakwater openings; however, the design for a possible federal channel is under consideration. NWP staff were interested in historical vessel transits, with a special focus on isolating transits for the largest (i.e., longest) vessels, identified as vessels 80 feet or longer, currently utilizing the area inside the breakwater. The Automatic Identification System Analysis Package (AISAP) software created by USACE-ERDC (2018) was used to analyze vessel traffic.

23 Feb 2023

AIS Data: An Overview of Free Sources

Abstract: The purpose of this Coastal and Hydraulics Engineering technical note (CHETN) is to describe the sources of Automatic Identification System (AIS) data available to the public, with a focus on federal employees who may need AIS data to carry out their official duties. AIS data, in this context, refer to both real-time and historic vessel position information.

17 Jan 2023

US Port Connectivity and Ramifications for Maintenance of South Atlantic Division Ports

Abstract: This study utilized automatic identification system (AIS) data to quantify vessel traffic patterns within a predominantly US port network from 1 January 2009 to 31 December 2020, with the methods validated using independent data sets collected between 1 January 2015 and 31 December 2019. The analysis focused on South Atlantic Division (SAD) ports. AIS-derived data characterized individual ports’ traffic and port-to-port connectivity for the network. With foreign vessel entrances and clearances (E&C) data, the AIS-reported vessel characteristics enabled calculation of ships’ physical volume, which was a reasonable proxy for tonnage at many SAD ports. The PageRank algorithm was then applied to port-to-port traffic, revealing how individual ports participate in cargo movement through the network. PageRank scores also provided insight into the maritime supply chain beyond traditional traffic metrics. For example, many East Coast SAD ports ranked higher by PageRank than by raw tonnage. Because of the supply chain implications of shared vessel traffic, PageRank scores can augment tonnage metrics when prioritizing channel and infrastructure maintenance. Vessel volume, port-to-port connectivity, and PageRank scores reveal maritime supply chain resilience by identifying alternative destinations for cargo bound for disrupted ports, robustness across supply chains, and the effects of seasonality and disruptions.

14 Jul 2022

Automatic Identification System Analysis Package User Guide

Abstract: The Automatic Identification System Analysis Package (AISAP) enables acquisition, statistical analysis, and visualization of Automatic Identification System (AIS) data from historic vessel position reports. The web-based AISAP software allows the users to choose which data they want to examine for a specific geographic area, time period, and vessel type(s). Built-in features provide vessel characteristics, arrival and departure information within a geofenced area, vessel travel time between two locations, vessel track line plots, and relative density plots of AIS data reports. AISAP accesses the Nationwide Automatic Identification System database hosted by the United States Coast Guard. This user manual provides training exercises for users to follow to familiarize themselves with AISAP procedures and workflows. These training exercises also provide examples of AISAP products.

25 Jan 2022

Freight Fluidity for the Port of Baltimore: Vessel Approach and Maritime Mobility Metrics

Abstract: The United States Army Corps of Engineers is tasked with maintaining waterborne transportation system elements. Understanding channel utilization by vessels informs decisions regarding operations, maintenance, and investments in those elements. Historically, investment decisions have been informed by safety, environmental considerations, and projected economic benefits of alleviating channel restrictions or shipping delays (usually derived from models). However, quantifying causes and impacts of shipping delays based on actual historical vessel location data and then identifying which causes could be ameliorated through investment has been out of reach until recently. In this study, Automatic Identification System vessel position reports were used to develop quantitative measures of transit and dwell-time reliabilities for commercial vessels calling at the Port of Baltimore, Maryland. This port has two deep-water approaches: Chesapeake Bay and the Chesapeake and Delaware Canal. Descriptive metrics were determined for each approach, including port cycle time, harbor stay hours, travel time inbound, and travel time outbound. Then, additional performance measures were calculated: baseline travel time, travel time index, and planning time index. The key finding of this study is that the majority of variability in port cycle time is due to the variability in harbor stay hours, not from channel conditions or channel restrictions.

24 Jan 2022

AIS Data Case Study: Evaluating Reception of AIS Position Reports on the Missouri River by LOMA AIS Sites in April and August 2020

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) describes a method for evaluating the received coverage from Automatic Identification System (AIS) shoreside sites along the Missouri River managed by the US Army Corps of Engineers (USACE) Lock Operations Management Application (LOMA), and presents the results of that analysis. The purpose is to identify AIS coverage gaps in the current system. Reception of AIS transmissions between shore-based transceivers and vessels is generally line-of-sight between the vessel and the AIS site antenna. However, signal reception may be affected by factors such as the distance and terrain between the vessel and the transceiver site, quality of the transceiver installation, state of the equipment either aboard the vessel or at the shore transceiver station, and atmospheric phenomena. Quantifying coverage gaps along the inland waterways system can inform research that uses AIS data, provide information on the performance of the AIS network, and provide guidance for efforts to address coverage gaps to improve navigation safety. In autumn 2020, severe shoaling was occurring on the Missouri River. As the shoals were identified, the Kansas City District requested the LOMA system transmit AIS Aid to Navigation (AtoN) to mark the shoals in several critical areas. However, vessel pilots sometimes reported that they were not receiving the AIS AtoN being transmitted. At the request of the Kansas City District, the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (ERDC-CHL), conducted a coverage analysis using data collected from the LOMA AIS transceivers in the area to determine if there were coverage issues and their extent and to aid in determining the best means of addressing any coverage gaps.

14 Jun 2021

AIS data case Study: identifying AIS coverage gaps on the Ohio River in CY2018

Abstract: This Coastal and Hydraulics Engineering Technical Note describes a method for evaluating the received coverage from Automatic Identification System shore sites and the availability of historic vessel position reports along the Ohio River. The network of AIS shoreside sites installed and operated by the US Army Corps of Engineers and the US Coast Guard receive information transmitted from vessels; however, reception of these transmissions is generally line-of-sight between the vessel and the AIS site antenna. Reception may also be affected by factors such as the quality of the transceiver installation aboard the vessel as well as the state of the equipment at the receiving site. Understanding how to define and quantify coverage gaps along the inland river system can inform research utilizing AIS data, provide information on the performance of the AIS network, and provide guidance for efforts to address identified coverage gaps.

2 Jun 2021

AIS data case study: quantifying connectivity for six Great Lakes port areas from 2015 through 2018

Abstract: This Coastal and Hydraulics Engineering Technical Note presents results from a preliminary examination of commercial vessel traffic connectivity between six major port areas on the Great Lakes using Automatic Identification System data collected from 2015 to 2018. The six port areas included in this study are Calumet Harbor, IL and IN; Cleveland, OH; Detroit, MI; Duluth-Superior, MN and WI; Indiana Harbor, IN; and Two Harbors, MN. These six locations represent an important subset of the more than 100 federally authorized navigation projects in the Great Lakes maintained by the US Army Corps of Engineers. The results are presented in the context of USACE resilience-related policy initiatives as well as the larger topic of maritime system resilience.