"October 1980."

I. Introduction -- II. Summary and conclusions -- III. Methods -- IV. Data analysis presentation The opacity of the visible emissions from the two stationary sources within the Petersburg Generating Station, Indianapolis Power and Light Company (IP&L), Petersburg, Indiana, were measured during the late afternoon hours on June 13, 1980. The sources investigated were the Unites 1 and 2 Stack and the Unit 3 Stack. All measurements were conducted remotely from off the plant site. Opacities were measured remotely with the NEIC Omega-1 Lidar which is a new instrumentation method. This method has been proposed in the Federal Register as Alternate Method 1 to Reference Method 9. Six sets of opacity measurements were made, the total of which was about 1.9 hours of observation, and about 740 individual measurements. The sets of measurements ranged in length from 7 to 30 minutes. Measurements were made at a temporal frequency of once about every 10 seconds. Allopacity measuremens were subsequently analyzed and reduced with the NEIC laboratory computer using the methods given in Alternate Method 1 (proposed).