The Effects of Superimposing Symbology on a Simulated Night Vision Goggle Display

Abstract

During low level, night vision goggle (NVG) helicopter flight, it is difficult and potentially unsafe for aviators to divert their attention from the external scene to obtain critical flight information from cockpit instruments. To address this problem, the U.S. Army is acquiring a system that superimposes flight symbology on the imagery seen through one of the NVG intensifier tubes. However, previous research indicates that superimposed symbology may distract the pilot's attention from obstacle detection, recognition, and avoidance, and may interfere with proper scanning patterns.This report describes the results of a research project designed to determine how well rotary wing aviators can monitor the simultaneous display of NVG imagery and symbology. The results showed a relatively small decrement in performance when the two types of information were presented together. Aviator performance with the system improved with practice and was related to pilot exper'ience and eye dominance. The aviators suggested several modifications for the symbology suite.The results of this research can be used to modify the proposed symbology suite and to develop operational procedures for fielding the equipment. The research also identifies additional NVG imagery and symbology issues that need to be investigated. EDGAR J JdHNS ONActing Director v ACKNOWLEDGMENTSThe authors express their appreciation to the following individuals who contributed to this project.From the U.S. Army Research Institute Aviation Research and Development Activity, Dennis K. Leedom provided overall guidance for the research, MAJ Dale Weiler Coordinated research subjects, and Larry Murdock conducted the statistical analyses. From Dynamics Research Corporation, Robert Simon and John Morey provided advice on the research design and reviewed a draft of the report.Five members of the Anacapa Sciences staff assisted in conducting the research. We thank Gary Coker for designing the computer architecture, writing the computer programs, and supporting the experimental sessions; Kenneth Persin for providing technical support; Annette Swan for scoring the scene data; Tina Pridgen for providing administrative, scoring, editing, and word processing support; and David Thill for serving as an experimenter.Finally, we thank CW2 Joseph Cogelia, who provided subject matter expertise in developing the scenarios and in identifying scoring criteria. Mr. Cogelia also served as an experimenter and compiled technical information for the project report.Although they are not mentioneu by name, we also thank the aviators who enthusiastically participated in this research. U.S. Army helicopter pilots routinely use night vision goggles (NVGs) to conduct low level flights at night. The most recent version of NVGs, the aviators night vision imaging system (ANVIS), allows the pilot to look under or around the goggles to read critical flight instruments. However, reading instruments that differ in illumination and optical distance from the external scene is difficult and potentially uns...