WGS 66
Overview
The World Geodetic System 1966 (WGS 66) was a geodetic datum used for geodesy and navigation. It was developed by the United States Department of Defense (DoD) and was the first in a series of World Geodetic Systems, which were later refined and replaced by WGS 72, WGS 84, and others. WGS 66 was the first attempt to create a consistent and accurate global geodetic reference system, and it laid the groundwork for the development of more advanced systems.
History
The development of WGS 66 was prompted by the need for a unified, global geodetic system that could be used for military and civilian navigation. Prior to its creation, various countries used their own geodetic systems, which often led to inconsistencies and inaccuracies when trying to navigate or map on a global scale. The United States Department of Defense took the initiative to develop a global system, resulting in the creation of WGS 66.
Methodology
The WGS 66 was based on the mean sea level ellipsoid, a mathematical model of the Earth's shape, which was derived from a combination of terrestrial and satellite data. This model was used to establish a global reference frame for geodesy and navigation. The system used a variety of data sources, including surface gravity measurements, satellite tracking data, and astronomical observations, to create a comprehensive and accurate representation of the Earth's shape and gravitational field.
Characteristics
The WGS 66 defined the Earth's shape as an oblate spheroid, a shape that is nearly spherical but slightly flattened at the poles and bulging at the equator. The major (equatorial) radius of the Earth as defined by WGS 66 was 6,378.145 kilometers, and the minor (polar) radius was 6,356.750 kilometers. The flattening factor, which describes the amount of compression, was 1/298.25.
Applications
WGS 66 was used for a variety of applications, including mapping, navigation, and geodesy. It was also used in the design and operation of satellites, as the system provided a consistent and accurate global reference frame that was essential for precise satellite tracking and positioning.
Limitations and Successor Systems
While WGS 66 was a significant advancement in the field of geodesy, it had several limitations. The system was based on a relatively small amount of data, and as a result, it had some inaccuracies. Furthermore, the system did not account for certain factors, such as plate tectonics, that can affect the Earth's shape and gravitational field.
These limitations led to the development of successor systems, including WGS 72 and WGS 84. These systems incorporated more data and advanced methodologies, resulting in more accurate and comprehensive geodetic systems.