12 July 1999 Effects of aircraft windscreens and canopies on HMT/D aiming accuracy: III
Author Affiliations +
Modern fighter aircraft windscreens and canopies are typically made of curved, transparent plastic for improved aero-dynamics and bird-strike protection. Since they are curved these transparencies often refract light in such a way that a pilot looking through the transparency will see a target in a location other than where it really is. This effect has been known for many years and methods to correct the aircraft head- up display (HUD) for these angular deviations have been developed and employed. The same problem occurs for helmet- mounted display/trackers (HMD/Ts) used for target acquisition. However, in this case, the pilot can look through any part of the transparency instead of being constrained to just the forward section as in the case of the HUD and his/her head position can be anywhere in a rather large motion box. To explore the magnitude of these aiming errors several F-15, F- 16, F-18, and F-22 transparency systems were measured from a total of 12 different eye positions centered around the HMD Eye (the HMD Eye was defined to be a point 1.25 inches to the right of the aircraft Design Eye). The collection of eye points for assessing HMT/D aiming accuracy were: HMD Eye, 3 inches left and right of HMD Eye, 2 inches above HMD Eye, and 2 inches forward of HMD Eye plus all combinations of these. Results from these measurements along with recommendations regarding means of assessing 'goodness' of correction algorithms are presented.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
H. Lee Task, Chuck Goodyear, "Effects of aircraft windscreens and canopies on HMT/D aiming accuracy: III", Proc. SPIE 3689, Helmet- and Head-Mounted Displays IV, (12 July 1999); doi: 10.1117/12.352838; https://doi.org/10.1117/12.352838

Back to Top