This report presents a non-contact ultrasonic technique to map the full-field surface deflection of railroad ties using known concepts of sonar-based distance measurements. Between September 2019 and July 2021, the University of California San Diego (UCSD) created a beam with six sonar sensors and performed field testing at the UCSD Rail Defect Testing Facility (RDTF) and at a Burlington Northern Santa Fe (BNSF) rail yard in San Diego, CA. The test results indicate the potential of this non-contact system to measure full-field tie deflections in three-dimensions (3D) and possibly detect defective tie-ballast support conditions such as center-binding.