Accurate Determination of the Solar Photospheric Radius
  The Solar Diameter Monitor measured the duration of solar meridian transits during the 6 years 1981 to 1987, spanning the declining half of solar cycle 21. We have combined these photoelectric measurements with models of the solar limb-darkening function, deriving a mean value for the solar near-equatorial radius of 695.508 +- .026 Mm. Annual averages of the radius are identical within the measurement error of +- .037 Mm. 
T. M. Brown (High Altitude Observatory, National Center for   Atmospheric Research, Boulder, CO) J. Christensen-Dalsgaard (T...