TY - JOUR T1 - Statistical Consideration of the Structure of Atmospheric Refractive-Index AU - , S.E. Falodun JO - Research Journal of Applied Sciences VL - 2 IS - 6 SP - 773 EP - 779 PY - 2007 DA - 2001/08/19 SN - 1815-932x DO - rjasci.2007.773.779 UR - https://makhillpublications.co/view-article.php?doi=rjasci.2007.773.779 KW - Refractive index KW -refractivity gradient KW -atmospheric layer KW -normal distribution KW -k-factor AB - In relation to the irregular vertical distribution of atmospheric refractive index, the mean effective-earth-radius-factor, k, was determined for Akure (7.15 N, 5.12 E) from experimental data and also, some variation characteristics of air refractive index with space and time were discussed. The air temperature, the water-vapour pressure and the barometric pressure were measured at various heights above the earth`s surface from which the distribution of the refractive index were obtained. Also, the refractive index was statistically considered and it was found that the average refractivity gradient of the atmospheric layer of thickness H (m) approximately follows the normal distribution. Hence, by introducing H, the height range of the propagation path and defining the mean gradient of M-profile in this range, the conception of the effective earth radius factor, k, was brought out. ER -