Hydrogen geocorona and solar Lyman-alpha line: 1. Rocket measurement of the solar line profile

A rocket-borne high-resolution echelle spectrograph was used to measure the profile of the solar hydrogen-Lyman-alpha line. The profile was normalized to an integrated flux of 5.2 ergs/cm² sec, the value of which was measured with a nitric oxide ion chamber carried on the same flight. The flux available for scattering by hydrogen in the geocorona was 2.8 × 1011 photons/cm² sec. The optical depth at the center of the telluric absorption line was about 5.6 in the slant path at a 60° zenith distance. The general features of the profile are in agreement with earlier measurements.