U.S. - Mexico (main page) | Project Details | Whiting Transfer
United States - Mexico Cooperative Charting Advisors Committee (Project Details)
Joint Hydrographic
Survey
International Chart Production
Tide Data Integration
Vertical Control
Personnel Exchanges
Training
Joint Hydrographic Survey in the Gulf of Mexico
One of the first major successes of this new partnership was a cooperative hydrographic survey carried out for the ports of Tampico and Altamira, conducted by the NOAA Ship THOMAS JEFFERSON in April-May 2004. Large ships, moving some eight and a half million tons via primary container ships of all sizes call on the Port of Altamira, and bulk and petroleum ships call on the Port of Tampico. This joint survey was planned to provide important new data for use in the production of a chart in the Gulf of Mexico and contribute to safer navigation for mariners in an area that is expected to see a significant rise in ship traffic in the near future.
The survey vessel used in this operation, THOMAS JEFFERSON is a 64m hydrographic survey vessel with two 9m hydrographic survey launches. It normally operates on the East and Gulf Coasts of the United States by NOAA to acquire near shore hydrographic surveys in support of marine transportation and commerce. The surveys of Tampico and Altamira consisted of both multibeam and side scan sonar data acquired simultaneously aboard the ship and independently aboard her launches. The survey area consisted of two 1:10,000 scale surveys in the area around the jetties and three 1:20,000 scale surveys offshore and between the ports. The depths in the survey area ranged from 5 in the vicinity of the jetties to 40 meters offshore.
THOMAS JEFFERSON completed 135 square nautical miles of multibeam and side scan sonar surveys in the approaches and discovered numerous uncharted wrecks and obstructions during the surveys. Below are the side scan sonar images of some of the wrecks discovered during these surveys.
Co-Production of an International Chart
A joint version of INT Chart 4144 was planned for compilation during the Cartographer Exchange period. This chart is part of a scheme designed by the IHO MesoAmerican Hydrographic Commission to provide seamless regional chart coverage through the collaborative efforts of member countries. The United States and Mexico had agreed to co-produce this particular chart as one of the initial activities of its joint Charting Advisors Committee. Plans are to follow-up and create an Electronic Navigational Chart (ENC) of INT 4144 by one of the Exchange cartographers.
During the planning of this survey, Mexico provided NOAA with details of their tide station installations and several months of data from the two stations (Tampico and Altamira). NOAA processed these data and computed preliminary MLLW datums for each. Harmonic analyses were performed to help construct the preliminary tidal zoning for the survey. These data were also used in the technology transfer and training program with the visiting hydrographers using data from their station to learn data processing tidal datum computation procedures. Benchmarks were established at the new station described above and tidal datum elevation information has been shared with the Mexican hydrographers for their future surveys.
In order to determine safe water, one of the most important correctors for hydrographic data are tides and water levels. Vertical control for the cooperative survey of Tampico and Altamira was planned and implemented using standard NOAA procedures. Historical data from nearby operating Mexican tide stations at Tampico and Altimira were obtained from Mexican counterparts and analyzed to produce preliminary tidal zoning for the survey using the NOAA tide station at Port Isabel, Texas as control. Because real-time data relative to datum could not be obtained and quality controlled in a timely manner for THOMAS JEFFERSON field operations from the existing Mexican stations, NOAA contracted with Texas A&M to install and operate a station to NOAA specifications during survey operations. Data from this gauge were transmitted over the NOAA GOES system for daily review and quality control. Datums were computed, tidal zoning was adjusted based on the new measurements, and final zoning and tide reducers from the gauge provided to the THOMAS JEFFERSON prior to them leaving the survey area. This new gauge was also established closer to the harbor entrance to provide tighter control than the existing Mexican station.
Hydrographic and Cartographic Personnel Exchanges
The first hydrographic personnel exchange occurred during the Fall of 2003. Mexico sent one of its hydrographers, LT Leonardo Tun, to spend four weeks aboard NOAA Ship RAINIER and subsequently two weeks in the processing and production offices of OCS headquarters. While aboard RAINIER, LT Tun learned multibeam data acquisition and processing methods used by NOAA. NOAA Ship RAINIER is a 70m purpose-built hydrographic survey platform with six 9m launches aboard. LT Tun then visited NOAA’s Pacific Hydrographic Branch in Seattle, Washington to observe the data being processed, quality assured and creation of products such as Smooth Sheets, H-Drawings and chart applications. He then followed the process through to NOAA Headquarters, visiting the Marine Chart Division (MCD) to observe the creation of products for the mariner including: Electronic Navigation Charts (ENC), Raster Charts and Lithograph Charts.
LT Juan Ramirez was provided detailed training in tides from the NOAA
Center for Operational
Oceanographic Products and Services over a two-week period. This training
included an overview of national water level program operations, and
detailed training in tides support for hydrographic survey operations.
This included project planning, tidal zoning, tide station operations,
tidal data processing and quality control, tidal datum computation,
final tidal zoning and tide reducer determination, harmonic analyses
and tidal prediction. Data from the Mexican tide stations were used
in support of the training. The training included a visit to the nearby
NOAA tide station in Baltimore, Maryland.
In June 2004, a team of four NOAA hydrographers and cartographers (Sean Legeer, Cathleen Barry, Castle “Gene” Parker and Ada Otter) spent three weeks with their counterparts at the DIGADHICAR headquarters in Mexico City. The primary objectives were to learn more about each country’s respective programs and procedures, to provide training in hydrographic data processing and to initiate the co-production of an International Chart (4144). This chart is part of a scheme designed by the IHO MesoAmerican Hydrographic Commission to provide seamless regional chart coverage through the collaborative efforts of member countries. The United States and Mexico had agreed to co-produce this particular chart as one of the initial activities of its joint Charting Advisors Committee.
The U.S. cartographic team was introduced to DIGHADICAR Cartographic Department’s methods for paper chart, raster and ENC production. Their process involves importing bathymetric data and topographic/shoreline information into a CARIS Geographic Information System (GIS) environment. Their method relies heavily on CARIS GIS for vectorization of the paper chart information. The digital file that results from this vectorization for the paper chart then becomes the basis for creation of both the raster chart and production of the ENC.
Training in Alternative Data Acquisition and Processing Methods
Two of the cartographers, who also specialize in hydrographic data processing, spent a week giving a special seminar at the Oceanographic Institute of the Naval Academy in the Mexican city of Veracruz on the Gulf Coast. Mr. Gene Parker gave a series of lectures to Mexican Navy officers and a civilian oceanography student that included an overview of the U.S. hydrographic program and a specific focus on shallow water multibeam and side scan sonar acoustic principles and processing. The integration of multibeam methodologies into the hydrographic process adds a new dimension in the complexity of data processing. There are many significant lessons learned from these experiences that can be taken advantage of as we all prepare to acquire and use these technologies.
Notes:
1 - Smooth Sheets are a product created from the verified and corrected bathymetric and feature data of recent hydrographic surveys, generally at 1:10,000 scale. The smooth sheet is a primary source for creating an H-Drawing at chart scale that is used to update the chart.
2 - DIGADHICAR has been reorganized since the time of this survey and is now called DIGAOHM (Dirección General Adjunta de Oceanografia, Hidrografia y Meteorología or General Directorate for Oceanography, Hydrography and Meteorology)
