The Air Traffic Situational Awareness Enhancement Act aims to significantly improve safety and operational efficiency at certain air traffic control towers. Specifically, it mandates the Federal Aviation Administration (FAA) to acquire and install certified Airborne Position Reference Tools at contract towers that currently lack modern situational awareness equipment within one year of enactment. Concurrently, for these same towers, the Secretary of Transportation must purchase, install, and maintain Standard Terminal Automation Replacement Systems (STARS) or equivalent systems, utilizing services directly from original equipment manufacturers or the FAA. To ensure effective integration of these new technologies, the bill requires the establishment of an appropriate training program for air traffic controllers employed by contract tower operators. This program will focus on the proper and efficient use of the enhanced situational awareness equipment. Furthermore, the Act authorizes the use of funds from the Airport and Airway Trust Fund for the acquisition, installation, and annual operating expenses of these certified tools. A key provision also includes retroactive reimbursement or grant funding for airport sponsors or towers that independently acquired and installed certified situational awareness systems, including APRTs or STARS, prior to the bill's effective date.