DigitalGlobe’s Advanced Elevation Series (AES) is a suite of elevation products that are reasonably priced with global coverage. By utilizing existing archive coverage and their constellation of 30 to 50-cm WorldView and GeoEye-1 satellites, DigitalGlobe is able to offer an industry first: global elevation data delivered in reasonable time frames at competitive market prices.
There are three basic product offerings within the AES: Mapping, Precision and Very High Precision elevation data. The three products are differentiated by their resolution and accuracy – this information is summarized in the table below. For each of the products, DigitalGlobe offers both a Digital Surface Model (DSM) which include human-made and natural features (such as trees, bushes and buildings); and a Digital Terrain Model (DTM) with these features removed. Other important specifications include:
- Minimum Order Size
- 100 square kilometers
- Geographic Coverage
- Price lifts do exist for some Asian countries
- Cloud Cover
- 5% or less
- Cloudy pixels in final product are identified with an Esri polygon shapefile
- Data Sharing
- Data can be shared with up to 5 end users for no additional charge
- Uplifts can be applied to accommodate more end users
A Summary Table of Key AES Product Specifications
|Resolution||Absolute Vertical Accuracy (LE90%)||Relative Vertical Accuracy (LE90%)||Absolute Horizontal Accuracy (CE90%)||Relative Horizontal Accuracy (CE90%)||Ground Control (GCPs) Required?||Formats Available|
|Mapping||8 m||8 m||5 m||10 m||8 m||No||DSM / DTM|
|Precision||4 m||4 m||2 m||5 m||4 m||Yes*||DSM / DTM|
|Very High Precision||2 m||2 m||1 m||2 m||3 m||Yes*||DSM / DTM|
* Horizontal and vertical accuracies stated here assume GCP accuracy of 50-cm CE90%/LE90% accuracy or better.
Below is a comparison of two Very High Precision products created over Dunedin, New Zealand: one is a DSM and the other a DTM. DSMs are commonly used in line of sight and watershed analysis as they include human and natural features; while DTMs are commonly used in orthorectification where a ‘true’ model of Earth’s surface is crucial for improved horizontal accuracy. In this animation, we start with the DSM and then transition to the DTM, using the same color ramp with low elevations in red and higher elevations in green.
With pricing to meet different budget requirements and global coverage, DigitalGlobe’s AES elevation suite is the ideal solution for:
- Regional studies which require an analysis of elevation.
- Academics in need of a reasonably-priced solution to replace dated and low resolution public sources.
- Engineers looking to replace costly field labor in distant lands.
- More accurate orthorectification, particularly in areas of high topographic change.
If you would like more information about the global AES offering by DigitalGlobe, you can send requests to firstname.lastname@example.org or call us at (720) 720-7988.