User examples

A page for librat users to add their examples. Put as much detail as you can, and upload any files / scripts that are required to the wiki unless they are large.



Validation of airborne waveform lidar simulations for a complex 3D savanna in Australia

Code, models, data and instructions are provided for lidar simulations. This document is a work in progress.

1. Building mixed tree-grass scenes

Generating tree and grass object files

OnyxTree tree models:
- direct parameterisation in OnyxTree
- adjustment of LAD to known distribution
- material mapping of leaves
Onyxtree grass models:
- matched to scene estimates of mean height and cover
- random distribution assumed
Scene objects:
- testing random vs. clumped distribution of trees

Validation of generated scenes

- ability to replicate measured CCP-FPC and SBA-FPC relationships
- comparison of measured and modelled gap size distributions

2. Librat lidar simulations

Simulating the airborne survey configuration

System parameterisation:
- transmitted pulse properties
- simulation of survey configuration

Table 1. Airborne survey configurations. These were used for planning lidar acquisitions for validation.
Configuration Parameters
A1
A2
A3
Flying height (m)
550
1000
1300
Flying speed (m/s)
55
55
55
Flight distance (km)
10
10
10
No. parallel flightlines
3
3
3
Ground overlap (%)
60
60
60
Pulse rate (kHz)
200
200
150
Scan rate (Hz)
113
80
63
Beam divergence (mrad)
0.5
0.5
0.5
Field of view (deg)
60
60
60

Batch processing using start




Post-processing of simulations



Visualisation of simulations



3. Comparison with measured lidar waveforms