Non-geodetically-aligned

Describing systems, data, or objects that are not precisely or consistently referenced to a geodetic datum. A geodetic datum is a standardized reference system that defines the shape and size of the Earth and the locations of points on its surface. Being non-geodetically-aligned indicates a lack of coherence or compatibility with this global, Earth-centered reference framework. This can result in discrepancies or errors when attempting to integrate data from different sources or perform precise spatial analysis. This state often arises from localized coordinate systems, historical surveys, or data processing techniques that haven't incorporated geodetic corrections. It implies a potential need for transformation or adjustment to align data to a common, geodetic standard.

Non-geodetically-aligned meaning with examples

• The legacy CAD drawings for the city's infrastructure were initially non-geodetically-aligned, complicating the integration of GPS-derived surveying data for a new mapping project. Accurate spatial analysis required complex transformation processes. The city’s GIS team used a sophisticated georeferencing process to rectify the old plans to align with the WGS 84 datum.
• Aerial photography, prior to georeferencing, may be considered non-geodetically-aligned as its initial orientation isn't directly linked to a global geodetic system. This means distances and directions measured from the aerial imagery are not directly comparable to those from ground-based surveying. The images require georectification before they can be accurately integrated with other spatial datasets.
• A sensor network deployed in a remote area might initially collect data that is not non-geodetically-aligned if each sensor uses its own local reference. Without establishing the positions in a geodetic coordinate system, it is difficult to relate to a common point and integrate with other geographic data. Integration requires establishing relationships between the various sensor local datasets.
• The early scientific data collected by space probes was often non-geodetically-aligned with the Earth's datums due to using the spacecraft's internal frame of reference for their location. Subsequent processing, often using radio ranging or optical tracking, was crucial to determine the precise location of the data relative to Earth's surface and relate the observations to a standard geodetic framework.