Abstract: A method and a hybrid 3D-imaging device for surveying of a city scape for creation of a 3D city model. According to the invention, lidar data is acquired simultaneously with the acquisition of imaging data for stereoscopic imaging, i.e. acquisition of imaging and lidar data in one go during the same measuring process. The lidar data is combined with the imaging data for generating a 3D point cloud for extraction of a 3D city model, wherein the lidar data is used for compensating and addressing particular problem areas of generic stereoscopic image processing, in particular areas with unfavourable lighting conditions and areas where the accuracy and efficiency of stereoscopic point matching and point extraction is strongly reduced.
Type:
Grant
Filed:
March 23, 2017
Date of Patent:
January 11, 2022
Assignees:
LEICA GEOSYSTEMS AG, AIRBORNE HYDROGRAPHY AB
Inventors:
RĂ¼diger Wagner, Anders Ekelund, Andreas Axelsson, Patrick Steinmann
Abstract: The invention relates to a method and a device for determining a return time of a returning light pulse by a Single Photon (SPL) LiDAR scanner, the SPL scanner comprising of a low photon count detector for converting low amounts of photons or single photons to electrical signals, and a control and processing unit for processing the data and for determining the return time of the returning light pulse. The control and processing unit identify detected photons potentially representing a return pulse event and create a return pulse signal based on a criterion involving a temporal probability distribution for the detected photons, identify a rising edge and a falling edge of the return pulse signal, and determine the return time for each return pulse event based on the rising edge and the falling edge of the return pulse signal.
Abstract: A method and a hybrid 3D-imaging device for surveying of a city scape for creation of a 3D city model. According to the invention, lidar data is acquired simultaneously with the acquisition of imaging data for stereoscopic imaging, i.e. acquisition of imaging and lidar data in one go during the same measuring process. The lidar data is combined with the imaging data for generating a 3D point cloud for extraction of a 3D city model, wherein the lidar data is used for compensating and addressing particular problem areas of generic stereoscopic image processing, in particular areas with unfavourable lighting conditions and areas where the accuracy and efficiency of stereoscopic point matching and point extraction is strongly reduced.
Type:
Application
Filed:
March 23, 2017
Publication date:
September 28, 2017
Applicants:
LEICA GEOSYSTEMS AG, AIRBORNE HYDROGRAPHY AB
Inventors:
RĂ¼diger WAGNER, Anders EKELUND, Andreas AXELSSON, Patrick STEINMANN
Abstract: The invention relates to a method and a device for determining a return time of a returning light pulse by a Single Photon (SPL) LiDAR scanner, the SPL scanner comprising of a low photon count detector for converting low amounts of photons or single photons to electrical signals, and a control and processing unit for processing the data and for determining the return time of the returning light pulse. The control and processing unit identify detected photons potentially representing a return pulse event and create a return pulse signal based on a criterion involving a temporal probability distribution for the detected photons, identify a rising edge and a falling edge of the return pulse signal, and determine the return time for each return pulse event based on the rising edge and the falling edge of the return pulse signal.