Services : Digital Imagery Inspection

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AMT personnel have been using digitally scanned aerial imagery in photogrammetric production for many years and possess valuable and specific expertise for the inspection these products.

The extensive ZI suite of imagery tools, utilities and batch processes allows us to apply our photogrammetric expertise efficiently and with confidence. For example, interior orientation residuals are the strongest indicators for the analysis of metric stability. ISDM is used for automated measurement of Interior Orientations on a line-by line basis. Other softcopy systems require the manual measurement of fiducials for each individual frame, which is considerably more time consuming. ISDM also provides superior image rotation tools that allow us to rotate complete flight lines in seconds.

Powerful batch image processing is performed with ZI's ImageStation Raster Utilities (ISRU), which allows us to efficiently process jpeg compressed production images from uncompressed tiff files. The amount of compression is completely flexible and the output images can be tiled or un-tiled. Other ISRU options include the batch creation of grey-scale imagery from colour source images and batch tonal balancing/dodging.

Processing production imagery without adding compression is interactive and can take up to 20 minutes per image/stereo-pair on other softcopy systems.

ISDM, as illustrated on page 3 in dual monitor operation, is used for efficient inspection of the flight mission with respect to forward overlap and sidelap percentages as well as for radiometric quality, resolution and other image quality issues.

Complete inspection of project imagery involves analysis to detect the presence of anomalies as well as to identify the source(s) of the anomalies, as listed below.

• Project area coverage
• Forward overlap
• Sidelap
• Crab
• Cloud/smoke/haze
• Sun angles

• Radiometric quality
• Film resolution
• Metric stability
• Film titling/annotation
• Dust/hair//scratches

• Image names: presence of all imagery, no duplicate imagery
• File corruptions
• Radiometric quality
• Metric stability
• Scan resolution
• Data drops
• Scan registration errors
• Dust/hair

All findings, anomalies and anomaly source(s) are reported in a formal Inspection Report.