Assessment and Planning covers a wide range of functions related to air quality control, including:       State Implementation Plan (SIP) development; national and state policy development; Development of rules and regulations to attain and maintain the National Ambient Air Quality Standards (NAAQS);   Stationary source emissions summation, data calculation, and emission modeling;   Air Use Permit ambient air modeling as well as Air Quality Index (AQI) forecasting; Support for mobile source planning and NAAQS transportation conformity; and   Technical evaluation and support for emissions trading programs