25 Jun 2024

The Effect of Increasing the Antenna Height on Radio Signal Reception at Tom Bevill Lock and Dam: LOMA-AIS Data Case Study

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) presents the effects on the reception of radio signals due to increasing the antenna height at Tom Bevill Lock and Dam (L&D) in Pickensville, Alabama. The signals are received Automatic Identification System (AIS) broadcasts from commercial vessels operating along the Tennessee-Tombigbee Waterway. These AIS broadcasts are received by the Lock Operations Management Application (LOMA) radio equipment at Tom Bevill L&D.

28 Feb 2024

Potential Lock Operations Management Application (LOMA) Hardware Installation Sites along the Ohio River to Improve Automatic Identification System (AIS) Reception and Transmit Range

Abstract: The purpose of this Coastal and Hydraulics Engineering technical note (CHETN) is to propose a list of candidate sites along the Ohio River for the installation of Automatic Identification System (AIS) shoreside towers within the US Army Corps of Engineers (USACE) Lock Operations Management Application (LOMA) program. The LOMA program manages a network of terrestrial (shoreside) AIS sites (Figure 1) and vessel-mounted AIS sites with receive and transmit capability. However, there are known limits to the reception and transmission areas served by existing shoreside towers (referred to as “coverage gaps”) along the Ohio River (DiJoseph et al. 2021). Parties interested in improving AIS coverage to enhance maritime domain awareness and navigational safety along the Ohio River may wish to pursue the installation of LOMA program hardware for this purpose.

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.