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Ground Control for Mapping

The photogrammetric process for creating accurate mapping from aerial imagery relies fundamentally on accurate ground control. Terrasurv has performed ground control surveys in all 50 states and internationally for projects ranging in size from a few acres to over 20,000 sq miles, and for a variety of scales from 3 cm GSD to 1 m and greater.

LiDAR projects require both accurate ground control points (GCP) and checkpoints (CP) to verify the accuracy of the delivered product. Terrasurv has extensive experience establishing ground control for Lidar in an accurate and economical manner for a variety of clients including numerous large USGS 3DEP projects in both urban and remote areas.

Mapping control surveys are typically performed using Real Time methods including RTK over cell, using a Virtual Reference Station (VRS) network, or Trimble Real Time eXtended (RTX) methodologies.

 

Example Project: A LiDAR project was contracted for Post-Harvey mapping of several areas in Texas.

Project Area:

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115 Ground Control Points (GCP) were surveyed:

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268 Non-Vegetated Check Points (NVA) were surveyed:

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137 Vegetated (VVA) checkpoints (non-woods) were surveyed:

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And 50 woods (VVA-F) checkpoints were surveyed:

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