Comparison of SMS Calculation Methods Based on NGSIM Data for UAV Detection

The introduction of UAV into transportation offers a great number of challenges such as how to utilize the collected vehicle data of different levels to obtain traffic variables. Meanwhile, different detection approaches may acquire different types and precisions of vehicle data, and the methods that will be chosen for each detection approach also may vary. The main objective of this paper is to compare the difference of several methods of calculating space mean speed (SMS), so as to provide guidance for SMS calculation and application based on various detection data of UAV. Two basic methods and three expanded methods that are possible to be used for UAV detection to calculate SMS of a road are discussed based on a dataset from NGSIM. Without considering the errors that may be caused by instability of UAV flight and video processing, differences among the methods are analyzed in the MatLAB software. The results of the two basic methods are of large difference, and the expanded methods used to estimate the SMS in various time periods will also generate different results. So when the results obtained by these methods are used for data fusion and other transportation applications, they should be assigned different weights. Some other results are obtained too, which may provide references for the traffic parameter extraction based on UAV detection, and the data fusion between the space mean speed from UAV detection and that from other traffic detection methods.