Esri ArcGIS Pro Foundation Certification Practice Test

To create a map to compare global data, which type of spatial reference should be used?

1. Geographic transformation

2. Projected transformation

3. Earth-centered datum

4. Local datum

The correct answer is: Earth-centered datum

When creating a map to compare global data, using an earth-centered datum is crucial. This type of spatial reference aligns with the Earth's center of mass, providing a consistent framework for representing global data across various geographic scales. Earth-centered datums are designed to account for the Earth's shape and rotation, making them ideal for applications that require accurate global analysis. In contrast, other types of spatial references may not offer the same level of accuracy or consistency on a global scale. Geographic transformations typically refer to converting between different geographic coordinate systems but may not be as useful when focusing on global comparisons. Projected transformations are useful for visualizing data in specific regions and providing a flattened view for analysis, yet they can distort distances and areas depending on the projection used. Local datums are designed for specific areas and can lead to discrepancies when applied to global contexts, as they prioritize accuracy for localized measurements rather than a broader global accuracy. By choosing an earth-centered datum, you ensure that the map maintains integrity in representing global data, facilitating accurate comparisons and analyses.