Vegetation structure is important for measuring forest growth and the carbon cycle. Developed by the University of Salford and Halo Photonics Ltd, the Salford Advanced Laser Canopy Analyser (SALCA) is a unique multi-spectral, full waveform laser scanner using two wavelengths allowing distinction between leaves and woody material. This blog follows our research funded by the UK NERC and involving University of Newcastle, University College London and UK Forest Research.
Friday, 8 April 2011
The First SALCA Trip
Delamere Forest, Cheshire, Plot 2
Just completed the first field measurements with SALCA at Delamere Forest, Cheshire. We selected a mixed Oak/Silver Birch stand (plot 2) that has been used in our previous research with Riegl laser scanners. The main aim was to test the equipment and in particular the new generator, and the filters that we have acquired to try to minimise saturation of some of the close-range waveforms.
It took some time getting ready for this first field trip with plenty of equipment to gather together, including generator, tripod, digital camera, not to mention a host of spirit levels, laptops and cables, this is definitely shaping up to be a 2-person job and one where the off-road pram really comes into its own - despite the funny looks you get from walkers and cyclists in the forest. The set up all worked out in the field and we couldn't have picked a better day for it, with clear blue skies overhead.
Phenological observations: We arrived about a week after bud burst of the birch trees and leaf opening had already started. There are buds on the oaks but the buds have not yet started to open. A recce of the area showed that the sweet chestnut stands were less advanced with only the first signs of bud growth.
Fisheye photo directly above plot 2
We completed two scans at full resolution, which will be compared to hemispherical photos of the canopy. However, the scans took considerably longer than the assumed 'fat-hour' per scan, with full scans completing in about 2 hours, so a low resolution scan was also completed to check the feasibility of this as an option. I will definitely have to bring something to do next time.
SALCA in operation
We will now have to start the data analysis in order to assess the effects of the different filters and in readiness for the next trip scheduled for next week.
All in all, this was a hugely successful trip: we have collected a lot of data, established our first sampling plot and ensured that the power supply works without any problems.