Field Assessment of Methane Emissions (IMAGE) Princeton University, Engineering School Caption James McSpiritt, an optomechanical engineer in Princeton University's Department of Civil and Environmental Engineering, adjusts an eddy covariance tower, a stationary device used to measure air pollution. The device allowed the researchers to collect data about methane emissions that they could compare to samples collected from the mobile laboratory. Credit Bernhard Buchholz Usage Restrictions non-commercial use License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.