Determining the Astronomical Refraction and Building the Radio Wave Refractive Delay Model Measured(Ⅳ)——Instantaneous Astronomical Measured Latitude

According to the principle of determining the astronomical refraction and requisites for building radio wave refractive delay corrective models, strict requirements of the instantaneous astronomical measured latitude are described, and the reasons why the instantaneous measured latitudes obtained via classic measuring instruments and by space geodetic surveying techniques are not suitable here are analyzed in the paper. A novel approach to find the instantaneous measured latitudes by differences between measured and calculated hour angles in given azimuths except for the meridian is presented so as to avoid residual errors of the refraction corrective value. Some basic demands on observational data processing are brought forward. Finally the feasibility of implementing the approach via the planned special measuring instrument is discussed.