Field trials (IMAGE) University of Utah Caption Volunteers were timed walking 100-meter transects chosen to represent off-path landscape conditions, including nearly impassibly steep slopes and extremely dense vegetation. Credit Utah Remote Sensing Applications (URSA) Lab Usage Restrictions Credit must be given to the creator. License CC BY 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.