Introducing two Mathematical Models using Data Functional Approximation to Determine the Shadow Angles and Lengths in North of Baghdad City

In this study, two models are presented to estimate a shadow angle and length of an object located outdoor during daytime. A stick, with 50 cm length and diameter 1 cm, used to measure the shadow angle and length from 9 am to 3 pm for 1 st , 11 th , 12 th , 21 st , 22 nd , and 31 st of August, 1 st , 11 th , 12 th , 21 st , 22 nd , and 30 th of September, 11 th , 12 th , 25 th , 26 th , and 31 st of October, 8 th , 16 th , 17 th , 25 th , 26 th , and 30 th of November, 1 st , 16 th , 17 th , 22 nd , and 23 rd December 2019. The introduced model’s results, for shadow angles and shadow lengths, show good agreement with the real data. The Normalize mean square error (NMSE) criterion used to measure the quality matching between the real and modeled data. The highest value of NMSE between the real and result shadow angles and shadow length from model is 0.006% and 0.003% respectively.