SlashScan: An iOS app for field-based, real-time slash pile mapping and volume estimation

Slash piles are accumulations of forest residues such as branches, tops, and unmerchantable logs that remain after logging or thinning operations. Left in place, they can create a wildfire hazard or interfere with regeneration, replanting, and other forest management activities. 

Photo Credit

Courtesy photo by Heechan Jeong

A slash pile on the research site in Starker Forest, Oregon.

Whether a manager plans to burn, dispose of, or utilize slash pile material, they need to accurately estimate the pile’s volume and location. This information:

• Feeds into assessments of fuel loads, which inform fire behavior modeling and prescribed burning intensity
• Supports biomass transportation logistics, cost estimation, and supply chain optimization for renewable energy production
• Guides the retention of some biomass on site to support various soil, habitat and biodiversity functions

However, better tools are needed to inventory slash piles across large forest landscapes and remote areas. 

An efficient, mobile, and low-cost method for slash pile inventory

To address this challenge, researchers at the Forest Service and Oregon State University developed SlashScan, a mobile application for iPhone and iPad that field-going foresters, fuels managers, and contractors can use to estimate the volume of slash piles and generate location data in real time. The app provides a practical, relatively low-cost way to inventory slash piles in the field – and quickly: it only takes about 30 seconds to estimate the volume of a pile. Further, it does not require internet connection to use. The app integrates LiDAR scanning, three-dimensional (3D) reconstruction, volumetric analysis, and geospatial mapping within a single platform and operates entirely on the device. 

Photo Credit

Figure by Heechan Jeong

Using an iPad 13-inch Pro, the SlashScan app does 360-degree scanning of a slash pile.

This app can improve efficiency in forest operations and management, particularly biomass removal and use in fire-prone landscapes. It can also save money. The Forest Service typically estimates pile volume using manual geometric methods, which are relatively simple but labor intensive. Drone-based (UAV) lidar methods are very accurate and efficient in the field over large areas but require relatively costly equipment and intensive data processing that is not generally done on site. SlashScan is both more accurate and less costly than manual geometric methods and has comparable accuracy to drone-based lidar, generating almost instantaneous volume estimates on the fly at lower cost, while simultaneously mapping piles.

The application is available for download from the Apple App Store. 

Purpose

SlashScan is a mobile app for iPhone and iPad that field-going foresters, fuels managers, and contractors can use to simultaneously estimate slash pile volume and generate location data in real time without additional equipment. SlashScan provides a practical, relatively low-cost way to inventory slash piles in the field where rapid volume estimation, accurate location and immediate results are important.

Applicability and Overview