The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest Environments

Three colour and depth (RGB-D) devices were compared, to assess the effect of depth image misalignment, resulting from simultaneous localisation and mapping (SLAM) error, due to forest structure complexity. Urban parkland (S1) was used to assess stem density, and understory vegetation (≤1.3 m) was a...

Full description

Bibliographic Details
Main Authors: James McGlade, Luke Wallace, Bryan Hally, Karin Reinke, Simon Jones
Format: Article
Language:English
Published: MDPI AG 2023-04-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/23/8/3933
_version_ 1797603510930374656
author James McGlade
Luke Wallace
Bryan Hally
Karin Reinke
Simon Jones
author_facet James McGlade
Luke Wallace
Bryan Hally
Karin Reinke
Simon Jones
author_sort James McGlade
collection DOAJ
description Three colour and depth (RGB-D) devices were compared, to assess the effect of depth image misalignment, resulting from simultaneous localisation and mapping (SLAM) error, due to forest structure complexity. Urban parkland (S1) was used to assess stem density, and understory vegetation (≤1.3 m) was assessed in native woodland (S2). Individual stem and continuous capture approaches were used, with stem diameter at breast height (DBH) estimated. Misalignment was present within point clouds; however, no significant differences in DBH were observed for stems captured at S1 with either approach (Kinect <i>p</i> = 0.16; iPad <i>p</i> = 0.27; Zed <i>p</i> = 0.79). Using continuous capture, the iPad was the only RGB-D device to maintain SLAM in all S2 plots. There was significant correlation between DBH error and surrounding understory vegetation with the Kinect device (<i>p</i> = 0.04). Conversely, there was no significant relationship between DBH error and understory vegetation for the iPad (<i>p</i> = 0.55) and Zed (<i>p</i> = 0.86). The iPad had the lowest DBH root-mean-square error (RMSE) across both individual stem (RMSE = <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2.16</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">c</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">m</mi></semantics></math></inline-formula>) and continuous (RMSE = <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>3.23</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">c</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">m</mi></semantics></math></inline-formula>) capture approaches. The results suggest that the assessed RGB-D devices are more capable of operation within complex forest environments than previous generations.
first_indexed 2024-03-11T04:33:09Z
format Article
id doaj.art-902dc3e0278d42e6bc86ab73641393d7
institution Directory Open Access Journal
issn 1424-8220
language English
last_indexed 2024-03-11T04:33:09Z
publishDate 2023-04-01
publisher MDPI AG
record_format Article
series Sensors
spelling doaj.art-902dc3e0278d42e6bc86ab73641393d72023-11-17T21:16:45ZengMDPI AGSensors1424-82202023-04-01238393310.3390/s23083933The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest EnvironmentsJames McGlade0Luke Wallace1Bryan Hally2Karin Reinke3Simon Jones4School of Science, Royal Melbourne Institute of Technology Univeristy, 124 La Trobe St, Melbourne, VIC 3000, AustraliaSchool of Geography, Planning and Spatial Sciences, University of Tasmania, Churchill Ave, Hobart, TAS 7001, AustraliaSchool of Science, Royal Melbourne Institute of Technology Univeristy, 124 La Trobe St, Melbourne, VIC 3000, AustraliaSchool of Science, Royal Melbourne Institute of Technology Univeristy, 124 La Trobe St, Melbourne, VIC 3000, AustraliaSchool of Science, Royal Melbourne Institute of Technology Univeristy, 124 La Trobe St, Melbourne, VIC 3000, AustraliaThree colour and depth (RGB-D) devices were compared, to assess the effect of depth image misalignment, resulting from simultaneous localisation and mapping (SLAM) error, due to forest structure complexity. Urban parkland (S1) was used to assess stem density, and understory vegetation (≤1.3 m) was assessed in native woodland (S2). Individual stem and continuous capture approaches were used, with stem diameter at breast height (DBH) estimated. Misalignment was present within point clouds; however, no significant differences in DBH were observed for stems captured at S1 with either approach (Kinect <i>p</i> = 0.16; iPad <i>p</i> = 0.27; Zed <i>p</i> = 0.79). Using continuous capture, the iPad was the only RGB-D device to maintain SLAM in all S2 plots. There was significant correlation between DBH error and surrounding understory vegetation with the Kinect device (<i>p</i> = 0.04). Conversely, there was no significant relationship between DBH error and understory vegetation for the iPad (<i>p</i> = 0.55) and Zed (<i>p</i> = 0.86). The iPad had the lowest DBH root-mean-square error (RMSE) across both individual stem (RMSE = <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2.16</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">c</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">m</mi></semantics></math></inline-formula>) and continuous (RMSE = <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>3.23</mn></mrow></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">c</mi></semantics></math></inline-formula><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">m</mi></semantics></math></inline-formula>) capture approaches. The results suggest that the assessed RGB-D devices are more capable of operation within complex forest environments than previous generations.https://www.mdpi.com/1424-8220/23/8/3933RGB-Dforestryinventorylow-costremote sensing
spellingShingle James McGlade
Luke Wallace
Bryan Hally
Karin Reinke
Simon Jones
The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest Environments
Sensors
RGB-D
forestry
inventory
low-cost
remote sensing
title The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest Environments
title_full The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest Environments
title_fullStr The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest Environments
title_full_unstemmed The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest Environments
title_short The Effect of Surrounding Vegetation on Basal Stem Measurements Acquired Using Low-Cost Depth Sensors in Urban and Native Forest Environments
title_sort effect of surrounding vegetation on basal stem measurements acquired using low cost depth sensors in urban and native forest environments
topic RGB-D
forestry
inventory
low-cost
remote sensing
url https://www.mdpi.com/1424-8220/23/8/3933
work_keys_str_mv AT jamesmcglade theeffectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT lukewallace theeffectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT bryanhally theeffectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT karinreinke theeffectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT simonjones theeffectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT jamesmcglade effectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT lukewallace effectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT bryanhally effectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT karinreinke effectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments
AT simonjones effectofsurroundingvegetationonbasalstemmeasurementsacquiredusinglowcostdepthsensorsinurbanandnativeforestenvironments