The relation of three main effects of eye-position on perceived direction was investigated using a method of hand pointing in the horizontal plane: (1) Retinal eccentricity is overestimated with respect to the fovea by a constant factor of 2.6 degrees; (2) an extraretinal signal induces a shift in perceived visual direction (slope 0.12) that is opposite to the direction of eccentric gaze; and (...

The Ice, Cloud and land Elevation Satellite (ICESat) in its 8 day repeat orbit mode provided data not only on the along-track surface slope, but also on the cross-track surface slope from adjacent repeat ground tracks. During the first 36 days of operation, four to five such repeat orbits occurred within 1 km in the cross-track direction. This provided an opportunity to use ICESat data to measu...

Smooth slopes can be displayed on treadmills through tilt mechanisms , but these mechanisms are typically too slow to present sudden slope changes. The Sarcos Treadport utilizes a mechanical tether that can apply horizontal forces to the user to simulate gravity forces. Psychophys-ical results are presented to show that slope display via tether forces is a reasonable facsimile for treadmill slo...

The curvature of the sea wave was tested as a parameter for estimating wave direction in the search for better results in estimates of wave direction in shallow waters, where waves of different sizes, frequencies and directions intersect and it is difficult to characterize. We used numerical simulations of the sea surface to determine wave direction calculated from the curvature of the waves. U...

Acoustic studies of several languages indicate that second-formant (F2) slopes in high vowels have opposing directions (independent of consonantal context): front [iː]-like vowels are produced with a rising F2 slope, whereas back [uː]-like vowels are produced with a falling F2 slope. The present study first reports acoustic measurements that confirm this pattern for the English variety of Stand...