Snow depth and water equivalent retrieval with UAV photogrammetry: toward an operational procedure for Arctic tundra watersheds

总部位于伊卡卢特的北极无人机公司为北极环境和社区的各种应用提供无人机（UAV）飞行和图像采集服务，包括土地测量，摄影测量，搜索和救援，现场检查和野生动物调查。拟议的项目旨在在北极冻土带环境中开发和测试基于无人机摄影测量的雪测绘方法。总体目标是开发和测试雪深和雪水当量的操作检索工作流程，包括衍生地图产品的准确性，并允许Arctic UAV Inc.将其纳入其业务服务套件。这项工作利用了伊魁特附近现有的雪科学活动和流域建模研究。无人机图像将用于在积雪覆盖和无雪条件下生成密集的地表地形三维点云，以便计算高分辨率积雪分布图。雪深将被转换成雪水当量使用现场和模式估计的密度。测绘产品的精度将根据现场测量来确定，并且将制定一份不使用现场测量来估计精度的协议，以提高北极无人机公司将提议的方法纳入使用长航时飞机的超视距（BVLOS）无人机应用的能力。BVLOS积雪测量是研究和发展的战略领域，因为许多北方水电公用事业需要及时准确地估计加拿大大片偏远地区的景观雪水当量。

Iqaluit-based Arctic UAV Inc. provides Unmanned Aerial Vehicle (UAV) flight and image acquisition services for a wide variety of applications in Arctic environments and communities, including land surveying, photogrammetry, search and rescue, site inspections and wildlife surveys. The proposed project aims to develop and test snow mapping methodologies based on UAV photogrammetry in Arctic tundra environments. The overarching objective is to develop and test a workflow for operational retrieval of snow depth and snow water equivalent including accuracies of the derived mapping products and to allow Arctic UAV Inc. to incorporate this into their suite of business services. The work leverages existing snow science activities and watershed modelling research near Iqaluit. UAV imagery will be used to generate dense 3-dimensional point clouds of surface topography during snow-covered and snow-free conditions in order to calculate high-resolution snow distribution maps. Snow depth will be converted to snow water equivalent using the field and model-derived estimates of density. Accuracies of the mapping products will be determined based on field measurements, and a protocol for estimating accuracies without the use of field measurements will be developed to advance Arctic UAV Inc.'s ability to incorporate the proposed methodologies into beyond visual line of site (BVLOS) UAV applications using long endurance aircraft. BVLOS snow surveying is a strategic area for research and development since many northern hydropower utilities require timely and accurate estimates of landscape snow water equivalent over large, remote regions of Canada.