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When Geospatial Evidence Matters

Many disputes hinge on what existed on the ground at a specific point in time — not just what exists today. Geospatial evidence is often critical in cases involving land use, boundaries, access, drainage, visibility, and environmental change.

 

Attorneys engage Mangsen Mapping when a case requires objective, defensible analysis of spatial conditions over time.

 

Common case contexts include:

  • Boundary and encroachment disputes

  • Adverse possession and prescriptive easements

  • Land-use and zoning conflicts

  • Grading, drainage, and runoff disputes

  • Vegetation, obstruction, and line-of-sight issues

  • Environmental change and site history reconstruction

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View our current list of cases worked on here.

My Role as an Expert Witness

As an expert witness, my role is to provide independent, objective analysis grounded in established geospatial methods and documented data sources.

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I assist attorneys by:

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  • Evaluating whether geospatial evidence is relevant and reliable

  • Interpreting historic aerial imagery, elevation datasets and other geospatial data

  • Explaining methods, assumptions and limitations clearly

  • Preparing court-ready maps, exhibits and reports

  • Supporting counsel through deposition, mediation and trial

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My work is focused on clarity, defensibility and transparency, ensuring that complex geospatial information can be clearly understood by judges, juries and opposing counsel.

How the Engagement Process Works

To reduce uncertainty and control scope, expert witness engagements follow a clear, structured process.

1. Initial Case Inquiry

Attorneys submit a brief case description to determine whether geospatial analysis is appropriate and whether the matter fits within my expertise.

2. Preliminary Geospatial Assessment (Retainer Required)

A paid preliminary review evaluates:

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  • Availability of relevant imagery, Lidar datasets and other geospatial data

  • Temporal coverage

  • Evidentiary potential and limitations

  • Recommended next steps

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This state allows counsel to make informed decisions before committing to a full expert engagement.

3. Full Engagement

If retained, services may include detailed analysis, expert reporting, exhibits, consultation and testimony support as needed.

Expert Analysis & Deliverables

Work performed may include:

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  • Expert reports and declarations

  • Court-ready maps, graphics and exhibits

  • Historic aerial imagery interpretation

  • Elevation, drainage and obstruction analysis

  • Change detection and timeline reconstruction

  • Deposition and trial preparation support

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All deliverables are prepared with litigation standards and evidentiary clarity in mind.

Qualifications & Experience

  • Certified Photogrammetrist, American Society of Photogrammetry and Remote Sensing​

  • GIS Professional, GIS Certification Institute

  • M.S. Geographic Information Systems, Penn State University

  • 700+ remote sensing projects processed from raw data into usable maps

  • 33+ legal matters

  • CLE instructor

"Nathan worked on a high stakes prescriptive easement case for me. His report combined data from multiple years and sources. It was a big part of the court ruling in my favor. I am forever grateful for his work."

 

-A.L., Client

"We have worked with Nathan on several environmental, land use, zoning, and other property cases where historic aerial images of changes in land use have provided critical evidence supporting our clients' arguments. His analysis is always thorough and precise and his presentations of complex technical material are clear and easy to immediately apply for our clients' benefit.  I look forward to working with Nathan on future cases and highly recommend him to other litigators handling property and environmental cases." 

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-Attorney

Objective analysis • Clear exhibits • Litigation support

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