New Models to Estimate Daytime and Shadow Length by Tracking the Shadow

In this study, models are presented to estimate the time from an object shadow angle and estimate the shadow length from daytime. A stick length of 10 cm used to measure the shadow length and shadow angle from 7 am to 5 pm for 1st, 11th, 12th, 13th, 21st, 22nd, and 30th September 2019. A new algorithm presented to extract the shadow length and angle automatically of work the images quickly and with high accuracy. The presented algorithm results for both shadow length and shadow angle show a good matching of the measured data. The introduced models' results, for daytime and shadow length, have good agreement with the real data. The highest value of Normalize mean square error (NMSE), used as a criterion for daytime data (from the first model) and real daytime, was 0.029%. The (NMSE) for the real shadow length and shadow length (online) was 0.011% while the value (NMSE) between real shadow length with the resulting model was less than 0.010%. This small percentage shows a good matching in the estimation of the daytime and shadow length of an outdoor object in the different day-times. The presented models can generalize globally.