We propose a modified algorithm for the gradient method to determine the near-edge smoke plume boundaries using backscatter signals of a scanning lidar. The running derivative of the ratio of the signal standard deviation (STD) to the accumulated sum of the STD is calculated, and the location of the global maximum of this function is found. No empirical criteria are required to determine smoke boundaries; thus the algorithm can be used without a priori selection of threshold values. The modified gradient method is not sensitive to the signal random noise at the far end of the lidar measurement range. Experimental data obtained with the Fire Sciences Laboratory lidar during routine prescribed fires in Montana were used to test the algorithm. Analysis results are presented that demonstrate the robustness of this algorithm.
© 2005 Optical Society of America
Original Manuscript: July 8, 2004
Revised Manuscript: October 14, 2004
Manuscript Accepted: October 27, 2004
Published: March 20, 2005
Vladimir A. Kovalev, Jenny Newton, Cyle Wold, and Wei Min Hao, "Simple algorithm to determine the near-edge smoke boundaries with scanning lidar," Appl. Opt. 44, 1761-1768 (2005)