DNR Open-File Project 401
Aeromagnetic Data Reprocessing Test

Background

Aeromagnetic Vertical Derivative Grids before (left) and after SI-Grid (right)

Graphic from Figure 5 in Contractor Report - Vertical Derivative Grids before (Conventional Grid - left) and after (SI-Grid right).

On July 19, 2017 the Department of Natural Resources released via Open-File format several files resulting from a pilot project to test whether legacy statewide aeromagnetic data products might be improved by additional reprocessing and re-gridding of the underlying data. Minnesota's existing statewide aeromagnetic data coverage and derived products provide geoscientists with a valuable remote sensing aid for interpreting bedrock geology in areas of the state covered by surficial materials.

The pilot project offers an opportunity to check whether advancements in computer processing and software can provide additional meaningful detail from the legacy data set, beyond that already extracted in the last round of reprocessing in 2007. Minnesota's world-class statewide digital aeromagnetic data coverage was acquired, compiled and published over a twelve year period from 1979-1991 by efforts of the Minnesota Geological Survey (MGS) through funding by the State of Minnesota Legislative Commission on Minnesota Resources (LCMR). In 2007, MGS reprocessed the original data set based on updated software and computing power and released the results for public use. The 2007 statewide aeromagnetic data coverage is available at the Minnesota Geological Survey website:
Statewide aeromagnetic data This link leads to an external site.»

The new pilot project data files are being released so that users of aeromagnetic data may gain access to the project files prior to development of a final report. The Department invites aeromagnetic data users to review, compare and provide feedback on the reprocessed data, gridded products and optional derived products, and whether similar reprocessing of other legacy data blocks might be beneficial.

Contractor report and data

The open file 'sha_pilot_jun12_2017.zip' contains a contractor report, Geosoft format databases, Geosoft format grids, and DXF format contact vectors produced by contractor Scott Hogg and Associates (SHA) as part of the test. The legacy data used for the pilot project crosses several geologic terranes and includes portions of three aeromagnetic data blocks (Mora, Grand Rapids and CUS-East), altogether covering approximately 24,500 km of flight line data in a configuration roughly 20 miles wide by 200 miles north-south. The report and associated data files are available to download here:
Report and data files (sha_pilot_jun12_2017.zip - 94 MB) »

For more information on this project, or to provide feedback, contact:

Dave Dahl
MnDNR Lands and Minerals
1525 3rd Avenue East
Hibbing, MN 55746
231-218-8445
Dave.Dahl@state.mn.us