Single photon lidar in mobile laser scanning: the sampling rate problem and initial solutions via spatial correlations

V. V. Lehtola, H. Hyyti, P. Keränen, J. Kostamovaara

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

3 Citations (Scopus)
72 Downloads (Pure)


Single photon lidars (in solid state form) offer several benefits over pulsed lidars, such as independence of micro-mechanical moving
parts or rotating joints, lower power consumption, faster acquisition rate, and reduced size. When mass produced, they will be
cheaper and smaller and thus very attractive for mobile laser scanning applications. However, as these lidars operate by receiving
single photons, they are very susceptible to background illumination such as sunlight. In other words, the observations contain a
significant amount of noise, or to be specific, outliers. This causes trouble for measurements done in motion, as the sampling rate (i.e.
the measurement frequency) should be low and high at the same time. It should be low enough so that target detection is robust,
meaning that the targets can be distinguished from the single-photon avalanche diode (SPAD) triggings caused by the background
photons. On the other hand, the sampling rate should be high enough to allow for measurements to be done from motion. Quick
sampling reduces the probability that a sample gathered during motion would contain data from more than a single target at a specific
range. Here, we study the exploitation of spatial correlations that exist between the observations as a mean to overcome this sampling
rate paradox. We propose computational methods for short and long range. Our results indicate that the spatial correlations do indeed
allow for faster and more robust sampling of measurements, which makes single photon lidars more attractive in (daylight) mobile
laser scanning.
Original languageEnglish
Title of host publicationThe International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Subtitle of host publicationOptical 3D Metrology
EditorsF. Remondino, M. Shortis
Place of PublicationStrasbourg
PublisherInternational Society for Photogrammetry and Remote Sensing (ISPRS)
Number of pages7
Publication statusPublished - 29 Nov 2019
Event1st Optical 3D Metrology Workshop 2019 - Strasbourg, France
Duration: 2 Dec 20193 Dec 2019
Conference number: 1

Publication series

NameInternational Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
ISSN (Print)2194-9034


Workshop1st Optical 3D Metrology Workshop 2019
Internet address



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