A new observation technique, suggested by recent advance in exospheric theory, appears useful for timely measurement of exospheric atomic hydrogen density, [H>. Fabry-Perot interferometer measurements of the geocoronal 0563 ¿ (∏&agr;) emission in the plane of the solar azimuth are used to approximately isolate the singly scattered resonant fluorescent intensity of H&agr; (ISS), thereby simplifying the derivation of [H>. This initial use of the technique procedures profiles of [H> from 400 to 10,000 km. The theoretical bulge of [H> in the early morning hours, previously escaping detection based on simple comparison of relative intensities, is now revealed with a magnitude exceeding the theoretical value. The measured ratio of [H> at 0430 local time to [H> at 2030 local times is 3.0+0.71-0.36 at 700 km, compared with a theoretical value of 1.72. At 2000 km we find no local time variation, in agreement with theory. Unlike nearly all previous studies, we find no arbitrary increase in the solar Lyman beta (Ly-&bgr;) flux is necessary to reconcile derived iISS with current models of exospheric [H>. Deriving absolute [H> remains subject to large systematic uncertainties (on the order of 50%), but the new method substantially improves upon linear extrapolation of relative density variations from H&agr; intensity changes. ¿ American Geophysical Union 1988