US 11,680,793 B2
Method for detecting thickness of tree canopy based on ultrasonic echo signal
Mingxiong Ou, Jiangsu (CN); Ming Wang, Jiangsu (CN); Weidong Jia, Jiangsu (CN); Huitao Zhou, Jiangsu (CN); Shiqun Dai, Jiangsu (CN); and Shuai Yang, Jiangsu (CN)
Assigned to Jiangsu University, Jiangsu (CN)
Appl. No. 17/627,693
Filed by Jiangsu University, Jiangsu (CN)
PCT Filed Aug. 5, 2021, PCT No. PCT/CN2021/110817
§ 371(c)(1), (2) Date Jan. 17, 2022,
PCT Pub. No. WO2022/017539, PCT Pub. Date Jan. 27, 2022.
Claims priority of application No. 202010725096.3 (CN), filed on Jul. 24, 2020.
Prior Publication US 2022/0364856 A1, Nov. 17, 2022
Int. Cl. G01B 17/02 (2006.01)
CPC G01B 17/02 (2013.01) 5 Claims
OG exemplary drawing
 
1. A method for detecting a thickness of a tree canopy based on an ultrasonic echo signal, comprising:
sending, by an ultrasonic sensor, an ultrasonic emission signal toward the tree canopy;
forming the ultrasonic echo signal by the tree canopy reflecting the ultrasonic emission signal; and
acquiring the ultrasonic echo signal, the ultrasonic echo signal being composed of voltage data and corresponding time data thereof,
wherein the voltage data generates an array Vi=[V1, V2, V3, . . . , Vn], the corresponding time data generates an array T=[T1, T2, T3, . . . , Tn], i=1, 2, 3, . . . , n, and a calculation formula of the thickness L of the tree canopy is as follows:

OG Complex Work Unit Math
wherein L is the thickness of the tree canopy, in meters, vo is a local ultrasonic propagation rate, in meters/second, Tx is a first effective peak time of the ultrasonic echo signal, in seconds, Ty is a last effective peak time of the ultrasonic echo signal, in seconds, k is a correction coefficient, when a leaf area index (LAI) of the tree canopy meets 1.5≤LAI≤4.0, k=1, when the leaf area index of the tree canopy is

OG Complex Work Unit Math
and when the leaf area index of the tree canopy is

OG Complex Work Unit Math