HomeNewsNewsletterArchivesAuthorsJobsVideoDirectoryTwitterEvents
Register to receive the LiDAR MAG Newsletter  
advertisement

eNewsletter

News

remove subscribe

LiDAR Magazine Today


 

follow us on Twitter 

Sponsored By


TAS Lidar Content
TAS Content
Videos
Meet the Authors
Check out our fine lineup of writers. Each an expert in his or her field.
Sponsored By


Partner Sites

American Surveyor

machinecontrolonline 

lbszone.com

GISuser.com

GeoJobs.biz

GeoLearn

 

Spatial Media LLC properties

Associates

ASPRS

Connect

LinkedIn Group
twitter
youtube
facebook group
rss

  LiDARmag     

Bluesky LiDAR Maps Used to Monitor the Spread of Deadly Tree Disease Print E-mail
Written by James Eddy   
Saturday, 10 June 2017

A 1.281Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

Laser maps collected by airborne mounted sensors have, for the first time, been used to successfully segment individual trees affected by the deadly Larch tree disease. The laser scanning surveys (LiDAR) were undertaken by aerial mapping company Bluesky and used to model tree canopy height models as part of a wider study to prove the effective use of the technology for disease identification and monitoring. 

Phytophthora ramorum is a funguslike pathogen which causes extensive damage and mortality to a wide range of trees and other plants. Generically referred to as ramorum, the disease was first discovered in the UK back in 2002 and has now spread to sites from Cornwall to Scotland, causing destruction in high profile areas including Epping Forest and the Forest of Dean.

"Current trends suggest that UK forests and woodlands are subject to a greater threat from exotic diseases, such as Larch tree disease, than ever before," commented Chloe Barnes, Postgraduate Researcher at the University of Leicester and author of the study. "While the use of LiDAR in forestry applications has become more common, its use to identify individual trees affected by diseases has, until now, been underutilized." 

LiDAR has been used extensively to derive canopy height models (CHMs); in fact it is one of the key datasets used to create Bluesky's unique National Tree Map. However, when trees are affected by disease, evidenced by defoliation and dieback, irregularities across the entire canopy add complications to the segmentation of individual tree crowns (ITCs).

Using the Bluesky LiDAR data, sample plots of two study sites in Wales were assessed using different segmentation algorithms. A series of raster format CHMs were computed at different pixel sizes and tested across a range of plantation larch plots in order to perform ITC delineation. 

"The three dimensional nature of LiDAR provides structural information on topography, canopy height, tree density and crown dimensions, which we have proved can be used to determine biophysical parameters and inform forest inventories," concluded Barnes. "The high resolution and accuracy of the data also enables the extraction of forest parameters associated with individual tree crowns, including the opportunity for the detailed study of forest condition and dynamics." 

In order to capture highly accurate LiDAR (Light Detection and Ranging) data, a survey aircraft equipped with a system of lasers is used. Lasers are transmitted to the ground and the time taken for the beam to be bounced back to the aircraft-mounted receivers is recorded. Using the known position of the aircraft (derived from on-board satellite positioning equipment), the time taken for the return of the laser beam and the known value of the speed of light, the distance between the aircraft and ground is calculated. 

Readings can also be taken to determine the height of buildings, vegetation and other surface structures such as above ground pipelines, highways, street furniture, power lines and railway tracks. 

Bluesky is a specialist in aerial survey including aerial photography, LiDAR and thermal data, using the very latest survey technology, including two UltraCam Eagles and a Teledyne Optech Galaxy LiDAR system integrated with a PhaseOne camera and thermal sensor. An internationally recognized leader with projects extending around the globe, Bluesky is proud to work with prestigious organizations such as Google, the BBC and Government Agencies. 

Bluesky has unrivalled expertise in the creation of seamless, digital aerial photography and maintains national "off the shelf" coverage of aerial photography, DTM and DSM through an ongoing three-year update program. By purchasing a world first sensor for the simultaneous capture of LiDAR, Thermal and Aerial Photography data, Bluesky is in the enviable position of being able to provide customers with unique and cost effective solutions. 

Bluesky is leading the way in developing innovative solutions for environmental applications, including the UK's first National Tree Map (NTM), solar mapping and citywide `heat loss' maps and is currently developing noise and air quality mapping products. For more information, visit: www.bluesky-world.com

James Eddy is Technical Director of Bluesky International.

A 1.281Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

 
< Prev   Next >

 

Share this page with your favorite social networks! 

deliciousrssnewsletterlinkedinfacebooktwitter

LiDARmag Exclusive Online-only Article ticker
Featured LiDAR MAG Events
List Your Event Here
please
contact LiDAR

Google
 
LiDAR MAG TOP NEWS


SITECO New
Products at
Intergeo 2017

GOT NEWS? Send To
press [at] lidarmag.com
INTERGEO TV
Online Internet Content

Sponsor


White Papers
Careers

post a job
Reach our audience of Professional land surveyors and Geo-Technology professionals with your career ad. Feel free to contact us if you need additional information.

News Feeds

 
Subscribe to LiDAR MAG updates via friendfeed

Need Help? See this RSS Tutorial






©Spatial Media LLC - All rights reserved / Privacy Statement
Spatial Media LLC
905 W 7th St #331
Frederick MD 21701
301-620-0784
301-695-1538 - fax