Status of the Vertical Geodetic Data at the Defense Mapping Agency Hydrographic/Topographic Center for Mexico and Central America,
Abstract
Since 1946, the Defense Mapping Agency (DMA) has been participating with Mexico and each of the Central American countries, as a result of the collaborative program under the Inter American Geodetic Survey for the production of cartogrpahic, geodetic, and geophysical products. The geodetic leveling network, which developed from these mapping agreements with each country, now contains over 50,000 kilometers of leveling. Gravity observations have also been observed over a large portion of these level lines. Most of these leveling data were adjusted by DMA in regional blocks as the basic leveling networks were completed. Each regional block was adjusted, holding mean-sea-level at the tidal stations equal to zero. Elevations of previously adjusted blocks were held fixed in each successive block adjustment. A test adjustment (1980) combining all of the first-order level links from the 1959 to 1972 regional adjustments was performed for analysis. Results of this 1980 Special Adjustment along with the current status of the leveling data in DMA files are presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1980
- Accession Number
- ADA089052
Entities
People
- Hiram H. Skaggs Jr