He earned his PhD in Physics (1978) from California Institute of Technology where he studied under Eric Becklin, Michael Werner and Gerry Neugebauer on board NASA’s Kuiper Airborne Observatory.
He was a Senior Principal Scientific Officer in 1986 before he left it to work as an Astronomer at the US National Optical Astronomy Observatories (NOAO) in Tucson Arizona.
As chair of the NOAO Steering Committee, Gatley led a collaboration team working on a project funded by the US Naval Observatory and NOAO to develop the world's largest InSb infrared detector array (the first megapixel device with a format of 1024 x 1024 pixels code-named Aladdin) which was adopted by major observatories around the world.
His team also developed the first color infrared camera for Kitt Peak National Observatory in collaboration with the Space Telescope Science Institute.
Gatley left NOAO for Rochester Institute of Technology in 1997 where he held several positions over his tenure including: Director of Chester F. Carlson Center for Imaging Science (1997), Dean of the College of Science, and Director[4] of the Center for Student Innovation and Undergraduate Research Support (2009).