Satellites aid continuous forest monitoring
REMOTE SENSING TECHNOLOGIES USED IN THE FOREST HAVE come a long way in recent times and many forest managers now rely on drones and LiDAR for day-to-day monitoring.
While the low cost of drones has driven their use, it’s the increased availability of imagery and technological advances from high above the canopy providing near real-time views that have been the catalyst for greater adoption of satellite information.
New satellites with the capacity to record and monitor vegetation change are now launched monthly and their ready availability and reduced access cost is enabling foresters to monitor a given location repeatedly to detect subtle changes in vegetation vigour and identify underlying trends.
Any such initiatives do, however, involve massive data sets and downloading and storing these for local processing can lead to unworkable delays. That has now been overcome by the advent of cloud storage.
This has enabled Indufor’s resource monitoring team to develop a Continuous Plantation Monitoring System (CPMS) that can access both free and commercial satellites (such as Planet) to provide timely and accurate information across forests.
Dr Pete Watt, head of Indufor’s Resource Monitoring Team, says the CPMS outputs save time and resources by allowing targeted field inspections. These are designed to quickly validate harvest areas and pinpoint areas of un-mapped change, disease or crop failure.
“For example, before going to the field, we run our Canopy Index (CI) model over the satellite image to check for any unusual deviations from expected benchmark values,” he says, adding that examples might include areas affected by foliar diseases or pockets of wind damage.
Algorithms have been developed to provide automated monitoring of such planned operations as harvesting, roading and plantation thinning. These events can be tracked by comparing images acquired at different points in time. The detection algorithm identifies the change and groups all similar pixels to produce a change layer that can be loaded into a GIS. The outputs include a summary of the area harvested to date.
Dr Watt will be among a number of experts presenting at the upcoming 2018 ForestTECH conference being run for forest resource managers, remote sensing specialists and inventory foresters later this month. It runs in Rotorua on November 14-15 and then again in Melbourne a week later. For more details go to www.foresttech. events.