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Software: Spectral Image Exploitation - QUAC®

QUAC (Quick Atmospheric Correction) is a very fast, empirical atmospheric correction code for hyperspectral or multispectral imagery that uses only in-scene information. No knowledge of sensor metadata is  required, the sensor need not be radiometrically calibrated, and automated batch operation is supported. While first-principles codes such as FLAASH® are the most accurate for well-calibrated sensors and clear atmospheric conditions, QUAC can be superior under stressing conditions such as thick haze or smoke, under cloud cover, and for long slant paths.

QUAC is paired with FLAASH in the Atmospheric Correction Module (ACM) for ENVI, the popular and powerful image visualization and processing software by Exelis Visual Information Solutions.

[Pullout: QUAC

Licensing or Purchase: To purchase the ENVI Atmospheric Correction Module (ACM), please visit the Exelis VIS website. For licensing the ENVI ACM by the month, please visit the CloudEO Store. For custom implementations of QUAC, please contact



The figure shows the QUAC-generated reflectance spectra of surface materials.