LiDAR remote sensing

Lecturer

Hooman Latifi

ECTS

5 ECTS

 

Aim

In this module you will gain a detailed understanding of the advantages and challenges of Earth observation using Light Detection and Ranging (LiDAR) systems. Compared to other types of remote sensing data, the data from active Light Detection and Ranging (LiDAR) systems is of particular importance for local studies, where the 3D component (height) of objects is of relevance. Commonly LiDAR data is applied it in the field of digital terrain modelling, in forestry – e.g. for canopy height assessment, or urban structure applications. LiDAR embraces a range of active remote sensing systems mounted on different platforms, which provide valuable information for characterization of horizontal and vertical structure of the earth surface by measuring the travel time of laser pulses in visible and near-infrared spectral domains. The quality of scanning depends on the nature of the LIDAR system (discrete-return or full waveform) as well as on a set of other terrain- and data-driven factors. This course provides you with an overview on the theory and applications of LiDAR data, with a particular focus on airborne laser scanning. Following the initial theoretical sections on the principles and basic characteristics of LiDAR data, diverse practical steps and exercises will be implemented to provide real-world examples to illustrate how the LiDAR point clouds can be applied to extract information on terrain, surface and vegetation. These information will be further employed to model vegetation structural attributes on multiple spatial scales ranging from single trees to landscape levels.

Content

Block 1: Introduction to LiDAR (how does laser scanning work?)

  • Reminder on general remote sensing issues: difference between active and passive sensing
  •  History of LiDAR measurements
  •  Basics of LiDAR data measurements (platforms, sensors)
  • Airborne vs. spaceborne LiDAR: history, applications and data access
  • Measurement of travel time of laser light (pulsed time of flight)
  • On the concept of “structure”: why a third dimension is crucial?

Block 2: Principles of LiDAR measurements

  • Platform navigation, orientation and positioning
  • Difference between types of data acquisitions: discrete return and echo waveform
  • The recorded parameters: elevation, height, signal intensity and co.
  • The concept of „single-pulse“ vs. „multiple-pulse“
  • How are the incoming returns recorded? first come- first served!
  • Terrestrial LiDAR measurement: one position, rotating scanner
  • Data formats and big data-management: each byte matters!

Block 3: Elevation models:

  • General thoughts: why are the elevation models essential?
  • Digital terrain models
  • Digital surface models
  • Normalized DSM (Canopy height models)
  • Application fields: Forest, landscape and habitat representations
  • Magnified focus on Forest (basic and derived parameters): Diameter at breast height,  height, tree type proportions, tree type mapping, crown closure, stem count, growing stock und aboveground biomass
  • Single tree measurements
  • Urban: City models, roof top and building footprints

Block 4: Exercises in Open-Source domain of LiDAR data processing (Fusion/LDV, LASTools, R)

  • Exercises on point cloud processing
    • Import, export, visualizations and rendering
    • Sample measurements, single tree measurements and associated tasks
    • Elevation models
    • Data trimming, cropping, smoothing and generalizing
    • Catalog and descriptive communication
  • Extraction of metrics for modeling purposes
    • Thoughts on metrics
    • Intensity: yes or no?
    • Multi-scale metric extraction
    • Multi-source metric extraction
  • Class works and workshops (CIP-Pool/Homework)
  • Literature review, discussion groups and public presentations

 

Coding

Coding examples and individual work will be covered

Software

Various software programs will be used, but mainly OpenSource software such as R.

Techniques

Different techniques will be introduced and practically applied.

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Content

The content of scientific with regard to the audience will be discussed.

General Course News and Updates

M.Sc. thesis presentation by Karsten Wiertz

Karsten Wiertz will present his M.Sc. thesis on Wednesday 14th at 11am in room 0.004 KW 86 with the title "Development of a semi-automatic remote sensing approach for change- detection of forest structures in Bialowieza Forest." From the abstract: The diversity of...

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M.Sc. thesis defense by Sebastian Roersch

Sebastian Roersch will defend his thesis "Development of a semi-automated method to measure solar potential" next Wednesday (14th) at 10 am in 0.004 OKW 86. From his abstract: "In the second half of the 21st century, it will be decided how big the impact of climate...

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M.Sc. presentation by Marina Reiter

Marina Reiter will present her M.Sc. thesis "Comparing Urban Green Spaces in German Cities Using Remote Sensing Data" on Thursday 8th of August at 11am in OKW 86, 0.004. Looking forward to a great presentation and lively discussion afterwards. From her abstract: "The...

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EAGLE Summer Dialogue 2019

Our 2019 EAGLE Summer Dialogue was a great success again and thanks a lot to all our EAGLE students who organised it. More than 100 participants enjoyed talks by Sandra Lohberger (RSS GmbH) and Alfred Schumm (WWF) who covered beside the technical aspects of their work...

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Field Work Course 2019

Within the EAGLE program many Earth Observation applications and techniques are introduced and practically executed with quite some computer work. However, remote sensing research also requires a sound understanding of the study area. Field work is therefore a crucial...

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textbooks on remote sensing

Our already published textbook on "Remote Sensing and GIS for Ecologists - using Open Source software" was very well perceived and we got very positive feedback. However, either an introduction or more advanced methods and data was asked for as well. Hence, we decided...

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