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Health care inequity in remote and rural Indigenous communities often involves difficulty accessing health care services and supplies. Remotely Piloted Aircraft Systems, or drones, offer a potentially cost-effective method for reducing inequity by removing geographic barriers, increasing timeliness, and improving accessibility of supplies, equipment, and remote care.We assessed the feasibility of drones for delivery of supplies, medical equipment, and medical treatment across multiple platforms, including drone fleet development and testing; payload system integration (custom fixed-mount, winch, and parachute); and medical delivery simulations (COVID-19 test kit delivery and return, delivery of personal protective equipment, and remote ultrasound delivery and testing).Drone operational development has led to a finalized, scalable fleet of small to large drones with functional standard operating procedures across a range of scenarios, and custom payload systems including a fixed-mount, winch-based and parachute-based system. Simulation scenarios were successful, with COVID-19 test swabs returned to the lab with no signal degradation and a remote ultrasound successfully delivered and remotely guided in the field.Drone-based medical delivery models offer an innovative approach to addressing longstanding issues of health care access and equity and are particularly relevant in the context of SARS-CoV-2.

Remotely sensed glaciological measurements can be expensive, often involving a trade-off between resolution, scale, and frequency. We report on a case study in which two low-cost techniques were used to generate digital elevation models and orthomosaics of an Arctic glacier in consecutive ablation seasons. In the first aerial survey we used an unmanned aerial vehicle and acquired images autonomously. The following year we took advantage of the helicopter used for site access, and were able to acquire images manually, for little additional helicopter time. We present a preliminary assessment of accuracy and apply these data to measure glacier thinning and motion.

We present a first assessment of UAS-derived orthoimagery and digital elevation data in the context of newly-released accuracy standards for digital geospatial data developed by the American Society for Photogrammetry and Remote Sensing. We outline results from two case studies using a commercially-available UAS, photogrammetry software, and an array of ground control and check points. Radial horizontal and vertical root-mean-square-errors (RMSE) were calculated as 0.05 m and 0.06 m, respectively, for one site, and 0.08 m and 0.03 m, respectively, for the other. Under the 1990 ASPRS standards, both surveys meet the requirements for Class 1 accuracy at the 1:500 map scale and at the 0.50 m contour interval. Under the newly-developed ASPRS standards, the reported errors fulfill the requirements for both horizontal and vertical mapping at the 10 cm RMSE level. Overall, these results provide initial direction for practitioners considering UAS surveying in the context of accuracy standards.

Small unmanned aircraft systems (UASs) are often suited to applications where the cost, resolution, and (or) operational inflexibility of conventional remote sensing platforms is limiting. Remote sensing with small UASs is still relatively new, and there is limited understanding of how the data are acquired and used for scientific purposes and decision making. This paper provides practical guidance about the opportunities and limitations of small UAS-based remote sensing by highlighting a small sample of scientific and commercial case studies. Case studies span four themes: (i) mapping, which includes case studies to measure aggregate stockpile volumes and map river habitat; (ii) feature detection, which includes case studies on grassland image classification and detection of agricultural crop infection; (iii) wildlife and animal enumeration, with case studies describing the detection of fish concentrations during a major salmon spawning event, and cattle enumeration at a concentrated animal feeding operation; (iv) landscape dynamics with a case study of arctic glacier change. Collectively, these case studies only represent a fraction of possible remote sensing applications using small UASs, but they provide insight into potential challenges and outcomes, and help clarify the opportunities and limitations that UAS technology offers for remote sensing of the environment.

Twin time-lapse cameras were set up to provide a convergent view of ten targets located on the surface of an Arctic glacier, near its terminus. Using photogrammetric analysis, daily target elevations were calculated over three winters and two ablation seasons. Results show that the glacier surface level dropped by approximately 2.9 and 2.5 m respectively over the 2009 and 2010 ablation seasons. GPS measurements suggest the associated average vertical errors were 0.105 m and 0.04 m respectively. Photogrammetric measurements indicated that thinning from melting exceeded surface gains due to ice inflow by a factor of ~ 5: 1 during 2009 and 2010. Horizontal flow rates of 6–12 mm d–1 were measured photogrammetrically during autumn 2008 and compared to interpolated winter rates established from GPS measurements, with differences ranging between 7.4% and 17.2%. The availability of a continuous series of data for the duration of the study allowed the start and end dates of each ablation season to be identified, making it possible to determine the length of each balance year. The results show the utility of time-series photogrammetry for observing surface elevation changes and dynamic processes in remote glacial environments.

Small unmanned aircraft systems (sUAS) are a relatively new type of aerial platform for acquiring high-resolution remote sensing measurements of Earth surface processes and landforms. However, despite growing application there has been little quantitative assessment of sUAS performance. Here we present results from a field experiment designed to evaluate the accuracy of a photogrammetrically-derived digital terrain model (DTM) developed from imagery acquired with a low-cost digital camera onboard an sUAS. We also show the utility of the high-resolution (0.1 m) sUAS imagery for resolving small-scale biogeomorphic features. The experiment was conducted in an area with active and stabilized aeolian landforms in the southern Canadian Prairies. Images were acquired with a Hawkeye RQ-84Z Areohawk fixed-wing sUAS. A total of 280 images were acquired along 14 flight lines, covering an area of 1.95 km2. The survey was completed in 4.5 h, including GPS surveying, sUAS setup and flight time. Standard image processing and photogrammetric techniques were used to produce a 1 m resolution DTM and a 0.1 m resolution orthorectified image mosaic. The latter revealed previously un-mapped bioturbation features. The vertical accuracy of the DTM was evaluated with 99 Real-Time Kinematic GPS points, while 20 of these points were used to quantify horizontal accuracy. The horizontal root mean squared error (RMSE) of the orthoimage was 0.18 m, while the vertical RMSE of the DTM was 0.29 m, which is equivalent to the RMSE of a bare earth LiDAR DTM for the same site. The combined error from both datasets was used to define a threshold of the minimum elevation difference that could be reliably attributed to erosion or deposition in the seven years separating the sUAS and LiDAR datasets. Overall, our results suggest that sUAS-acquired imagery may provide a low-cost, rapid, and flexible alternative to airborne LiDAR for geomorphological mapping.

Proglacial icings are one of the most common forms of extrusive ice found in the Canadian Arctic. However, the icing adjacent to Fountain Glacier, Bylot Island, is unique due to its annual cycle of growth and decay, and perennial existence without involving freezing point depression of water due to chemical characteristics. Its regeneration depends on the availability of subglacial water and on the balance between ice accretion and hydro-thermal erosion. The storage and conduction of the glacial meltwater involved in the accretion of the icing were analyzed by conducting topographic and ground penetrating radar surveys in addition to the modelling of the subglacial drainage network and the thermal characteristics of the glacier base. The reflection power analysis of the geophysical data shows that some areas of the lower ablation zone have a high accumulation of liquid water, particularly beneath the centre part of the glacier along the main supraglacial stream. A dielectric permittivity model of the glacier – sediment interface suggests that a considerable portion of the glacier is warm based; allowing water to flow through unfrozen subglacial sediments towards the proglacial outwash plain. All these glacier-related characteristics contribute to the annual regeneration of the proglacial icing and allow for portions of the icing to be perennial. Copyright © 2013 John Wiley & Sons, Ltd.

Remotely-sensed glaciological measurements can be expensive, and often involve a trade-off between resolution, scale, and frequency. In an attempt to overcome these issues we report on a case study in which two low-cost techniques were used to generate orthomosaic images and digital elevation models (DEMs) of an arctic glacier in two consecutive ablation seasons. In the first aerial survey we used an unmanned aerial vehicle (UAV) and acquired images autonomously, while in the second we used a piloted helicopter and acquired images manually. We present a preliminary assessment of accuracy and apply these data to measure glacier thinning and motion.

SYNOPSIS The paper reviews general applications of remotely sensed data within the fields of forestry and environmental, management, and the potential of such data for resource assessment and monitoring. The various satellite systems and sensors available for resource surveys in South Africa are discussed; and comparisons are made in terms of data formats, mapping feasibilities, operating scales, and cost-effectiveness. The applicability of both digital processing and visual interpretation techniques are assessed, now that precision-corrected hard copy imagery is available in Gauss Conformal projection; and that GISs are becoming an acceptable management tool in South Africa. Forestry and associated environmental management applications are reviewed in some detail. Examples include the capability for species level inventory, forest structure analysis, leaf area index measurements, biomass estimates, canopy chemistry, stress/disease assessment, fire and fire management; and wildlife habitat evaluation.

Interferograms were generated from 10 TerraSAR-X image pairs, with the objective of obtaining estimates of winter surface motion for a slow-moving polythermal arctic glacier. Flow directions were computed using both ascending and descending-pass interferograms for each period, with the median value being adopted as the final direction. The weighted average flow was computed, with weighting based on the inverse of the difference between the ascending and descending-pass displacement estimates for each date. This study uses multiple interferograms with different imaging geometries to provide estimates of down-glacier flow. The methodology adopted minimizes the effects of glacier / satellite track alignment and those resulting from vertical motion of the glacier surface. Current velocities were compared with flow estimates derived from a 1992 ERS-1 image pair. The velocities were similar over most of the glacier, but current velocities were found to be 30% to 50% lower on the lower glacier.

To understand and predict Earth-surface dynamics, scientists often rely on access to the latest remote sensing data. Over the past several decades, considerable progress has been made in the development of specialized Earth observation sensors for measuring a wide range of processes and features. Comparatively little progress has been made, however, in the development of new platforms upon which these sensors can be deployed. Conventional platforms are still almost exclusively restricted to piloted aircraft and satellites. For many Earth science research questions and applications these platforms do not yet have the resolution or operational flexibility to provide answers affordably. The most effective remote sensing data match the spatiotemporal scale of the process or feature of interest. An emerging technology comprising unmanned aircraft systems (UAS), also known as unmanned aerial vehicles (UAV), is poised to offer a viable alternative to conventional platforms for acquiring high-resolution remote sensing data with increased operational flexibility, lower cost, and greater versatility (Figure 1).

This paper describes an approach to the provision of tool support for two particular aspects of requirements analysis: method support by active guidance, and specification interpretation and validation by animation. Method guidance is supported by a method model used to describe the sequence of method steps that should be followed. Animation provides an indication of the dynamic behaviour of the specified system by walking through a specification fragment to follow some scenario of interest. This approach to tool assistance has been tested by implementing a prototype set of tools for the CORE method and the Analyst workstation, and by application to a major case study. The current status of that work is described and evaluated.