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Published June 1988 | public
Journal Article

Verification of image processing based visibility models

Abstract

Methods are presented for testing visibility models that use simulated photographs to display results of model calculations. An experimental protocol is developed and used to obtain input data including standard photographs of chosen scenes on a clear day and during a smog event at Pasadena, CA. With the clear day photograph as a substrate, pollutant properties measured on the smoggy day are introduced into the visibility model, and results of the model calculations are displayed as a synthetic photograph of the expected appearance of the smog event. Quantitative comparisons are made between the predicted and actual appearance of the smog event. Diagnostic techniques developed are applied to the visibility modeling procedure proposed by Malm et al. That model is shown to reproduce the contrast reduction characteristic of urban air pollution but produces synthetic photographs with sky elements that differ substantially from a real photograph of the actual smog event.

Additional Information

© 1988 American Chemical Society. Received for review December 16, 1986. Accepted November 5, 1987. This research was supported by the California Air Resources Board under Agreement A2-077-32. We thank Shohreh Gharib for assistance with filter handling, Dana Brennen for preparation of distance images, Chris Tiller for help during the field experiments, and Kenneth McCue for help in constructing Figures 5 and 6. Assistance with the chemical analysis was rendered by James Huntzicker of the Oregon Graduate Center, Thomas Cahill and his staff at the University of California-Davis, and John Cooper of NEA Inc. The South Coast Air Quality Management District provided information on gaseous pollutant concentrations.

Additional details

Created:
August 19, 2023
Modified:
October 26, 2023