Sunday, 3 July 2016

Laser Scanning at Tumbarumba - DWEL, Riegl VZ-400, CBL and Zebedee

Recently a team from CSIRO traveled to the TERN Flux and Supersite at Tumbarumba in NSW to complete a week of laser scanning with DWEL, a Riegl VZ-400, a Compact Biomass Lidar (CBL) and two handheld Zebedee units.

Figure 1. The Tumba laser scan team, from left to right, Steve Zegelin, Mark Kitchen, Will Woodgate, Eva van Gorsel, Tom Jovanovic, Mick Schaefer and Debbie Crawford.

The Tumbarumba site is located in the Bago State forest in south eastern New South Wales. The forest is classified as wet sclerophyll, the dominant species is Eucalyptus delegatensis, and average tree height is 40 m. Elevation of the site is 1200 m and mean annual precipitation is 1000 mm. 

The mission at Tumbarumba was to scan and completely characterise the core 1 ha TERN Supersite plot. This involved collecting approximately 35 Riegl scans, 150 CBL scans, 18 DWEL scans and combining around 24 scans from the two Zebedee units. At each of the Riegl scan locations, digital hemispheric photographs were also collected.

While on-site, we also collected a few hi-res Riegl Scans from a unique angle, the top of the 70 m Flux Tower! This was a herculean effort from Will and Mark to climb to the top of the tower with the laser scanner in tow, but we think that the scan data will be well worth the effort. Care was taken while at the top of the tower to scan in the footprint of the towers' hyperspectral imaging system so that we can merge the laser scan data with that of the hyperspectral imagery, this will make a very interesting data set indeed!

Figure 2. Mark and the Riegl VZ-400 perched securely at the top of the tower, and the view out over the tree canopies.

Tuesday, 15 March 2016

Recent publications

1) Who knew? A five-parameter model for calibrating the Dual Waveform Echidna Lidar? That’s what it took to cover the range from 1 m and beyond, thanks to telescopic effects that decrease the signal from midrange (10-12 m) toward the instrument and Lambert’s Law, which decreases the signal from midrange to far range. See the fit in a new Sensors article by Zhan Li et al.

And even though it's not really a DWEL article...

2) Road trip! Attaching a SICK lidar and an active optical sensor to their 4-wheel drive SUV, Michael Schaefer and Dave Lamb recently cruised through a tall fescue pasture, mapping biomass from height and NDVI. You can read how they did it in their recent article in Remote Sensing.

And there are plenty more DWEL related publications over at the TLSIIG website. Thanks to Alan for these neat article intros!

Monday, 14 March 2016

Himalayans in the Mist

A little bit of eye candy to start the week off on a good note!

This is an image produced from a scan taken a while ago at the Arboretum here in Canberra. The image is produced from the intensity information recorded from the 1556nm laser.

Tuesday, 12 January 2016

Happy New Year!

Happy New Year everyone! All the best for 2016.

We have been a bit quiet on here in the past few months but we have a big 2016 planned so stay tuned...

Tuesday, 25 August 2015

DWEL & Zebedee at Canberra Arboretum - Part 2

Last week the bad weather finally cleared so we headed back out to the National Arboretum Canberra to collect scans a year on from the start of a collaborative project between CSIRO and the Australian National University. The project uses DWEL and Zebedee (a CSIRO handheld laser scanner) to monitor the growth, plant morphology, and health of some of the 94 small 'forests' that are planted in the arboretum. Preliminary views of the data show that several species of trees within the Arboretum have grown significantly over the year, in some cases up to 2.00m taller as well as the canopy filling out. We will now conduct scientific analysis and validation on selected trees within each of the scanned forests.

Monday, 27 July 2015

Online Visualization of your Lidar Point Clouds

I recently came across this website (Sketchfab) that allows you to upload your point clouds and visualize them online (like in this blog). You may have already seen it before, but if not I thought I would put it out there, there is only one catch, in the free account you can only upload files less than 50MB in size.
I will be using it from now on to post sample DWEL scans. Click the viewer below to see how it works!

C_Kara005_1064nm by mick.schaefer13 on Sketchfab

Tuesday, 2 June 2015

CBL up North

Recently a team of researchers from CSIRO traveled up to Northern QLD for a grassland biomass monitoring and satellite radar validation project. The field sites were located on the Spyglass Beef Research Facility a cattle property of approximately 100,000 hectares in size which is to be used as one of the pilot sites for the GEOGLAM-RAAP project.
Mapping out where to go next
We carried out many measurements including, soil moisture, point intercept, CBL (compact biomass lidar), destructive biomass sampling, field spectroscopy, tree structural measurements and ground cover.
Starting up the CBL for another scan.

It was very dry on the property, so more often than not the field sites didn't have much ground biomass at all, however it was a good exercise in establishing a baseline to work from and also the field protocols that we will use in the future.
Very dry and sparse vegetation courtesy being enduring 4 years of drought