The Temporal and Spatial Positioning Model Based on the Principle of Analemmatic Sundial in Different Parameters
Yu Liu, Zhu Xuedong, Xuefa Xia · 2016
Measurement Error Filter RuleAbstractWhen analyzing the data of photos and videos, it's very important to determine the shooting time and place.Usually, we can get the sun's shadow from the pictures and videos and establish different mathematical models to solve time and space positioning problems by the known parameters.Firstly, use basic amounts to establish Analemmatic sundial model; when obtaining a series of picture messages, you can get vertex coordinate data of a fixture's sun shadow on the level ground.Then to establish |y/x| scale model by Orthogonal multinomial fitting method, which can solve the latitude and longitude separately, and select 1 ‰ screening indicator as the error correction to get exact location; About shooting time, according to |y/x| scale model determining the position longitude, using MATLAB to enumerate solar declination, then develop Dynamic measurement error filter rule, select the appropriate latitude and solar declination values to calculate shooting date; when getting a video recording a fixture shadow changes, use MATLAB function of Videoreader frame image, then use Rgb2gray Function convert into gray image, finally use Ginput Function reads the image coordinates.Use those to establish a comprehensive model to get the time and location of the video shoot.Accomplish data analyzing work, which has important applications in the investigation, pointing prediction, spatial and temporal positioning and so on.