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Nevada Test Site Calibration Range and Geometric Calibration of Digital Cameras ISPRS I/2 Bob Kletzli Spectrum Mapping, LLC December 2-4, 2003. Outline. Engineer Sensor For Geometric Stability Lock Lenses at Infinity Before Calibration Lab Radiometric Calibration
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Nevada Test Site Calibration Range and Geometric Calibration of Digital CamerasISPRS I/2Bob KletzliSpectrum Mapping, LLCDecember 2-4, 2003
Outline • Engineer Sensor For Geometric Stability • Lock Lenses at Infinity Before Calibration • Lab Radiometric Calibration • Terrestrial Geometric Calibration • In Situ Calibration • Calibration Verification NTS
Geometric Stability • CDD Fixed To Milled Optical Bench • Lens Receptacle Is Opposite Side • Each Lens Fixed To Aluminum Socket • Lenses Are Interchangeable • Alignment Pins Eliminate Rotation • TEC Surrounds CCD • “Shake and Bake”
Lens Focus • Lens Focused At Infinity • High Frequency Target At 100m • Each Lens Adjusted & Pinned
Radiometric Calibration • Lab Tools Include: • Integrating Sphere • Spectralon Panels • Spectral Line Lamps • Lab Processes • Dark Current • Flat Fielding • White Balance
Insitu Range (NM) • 400+ points by RTK • 2-3 cm accuracy • Photo Identifiable • Variable terrain • Used for both laser & photography • Building corners surveyed
Summary • Digital Cameras Can be Calibrated to Conventional Specifications • Calibrations Are Maintained Over Time • Regional Test Ranges Are Extremely Useful For Calibration and Verification