1. Ground Control Report
    1. Vertical and Horizontal Ground Control, DEMs, and Error Budget

FIX v2.4 updated to v2.4.1 – redownload if you have v2.4

The SDMI control report is now published and available (downloads below). The control report’s objective is to summarize control requirements for horizontal and vertical control necessary to meet the target of National Map Accuracy Standards at 1:24,000; and provide alternative methodologies for meeting the specification. Alaska poses a major challenge in terms of ortho-controlling regional coverages of imagery and elevation data. The extremes of terrain from sea level to 6,000 meter plus mountain peaks make a consistent ortho control model difficult. Logistics involved with ground control are also a formidable challenge. This report summarizes the issues associated with control of Alaska imagery and elevation data; provides a report on methods currently used by mapping agencies and firms; and proposes methods for control standards, and serving up ground control from a common repository.

Map of existing potential control sources in the state: (click for more detail)