## 4 Conclusion  
The past decade's proliferation of UAS platforms and sensors provides unprecedented choices: where authorized, users may choose based on capability and, to an increasing degree, budgetary constraints. The continued trend of increasingly miniaturized components promises an era of tailored systems for on-demand remote sensing at extraordinary levels of sensor precision and navigational accuracy. The latter capability in particular will lead to the ability of researchers to remotely establish study sites at small spatial scales for fine-scale projects that can be repeatedly sampled without resorting to ground-control points, frequently obviating the need for site visits. While costs can be difficult to assess per mission or per flight hour due to varying requirements for personnel, sensors, and logistical support, improved reliability and technological miniaturization may be expected to reduce acquisition or operation costs. The capabilities found in UAS offer to revolutionize natural-resources management, remote sensing, and numerous other fields to the same degree as the advent of GIS two decades ago. The utility of UAS in fire mapping applications, for example, has been clearly shown in a number of demonstrations on aircraft of varying size and capability. Based on recent demonstration missions, the US Forest Service envisions using LASE (Low altitude, short endurance) and MALE (Medium altitude, long endurance) UAS for fire detection and active fire monitoring missions. VTOL aircraft are particularly appealing in wildfire and disaster response situations where access to improved surface runways are seldom guaranteed. Beyond fire and disaster response, LASE and MALE UAS aircraft will provide a host of cost-competitive applications in resource mapping and monitoring applications. Envisioned applications include:  
* Forest health monitoring: This application requires advanced electro-optical (E/O) sensor payloads, such as near-infrared and (in some cases) hyperspectral. Due to large areas of coverage required, MALE UAS are likely to be favored in the near term. * Forest inventory: Coarse-scale inventory requiring lightweight E/O sensors may allow the use of LASE UAS, which would confer the additional advantage of operation away from runways. * Wildlife surveys: Terrestrial flights for large-animal surveys have been conducted using LASE UAS, while MALE aircraft may be preferred for marine surveys due to requirements for extended operations. * Avalanche patrols: Depending on local facilities and preferred operations styles, this application may utilize either MAVs carried by rescue personnel, or LASE or MALE UAS operated from larger or fixed stations. * Air quality monitoring: Sampling payloads may require the additional lift capacity of larger UAS, but generally the geographic scope of the mission profile will determine whether short-duration flights by VTOL or the greater coverage and duration offered by LASE or MALE UAS are preferred. * Plume tracking: For monitoring of water pollution, repeated flights from local platforms may be accomplished by VTOL UAS. However, extensive surveys such as those required to track oil spills may make MALE UAS preferable. Payload requirements, which will impact platform choice, will be driven by specific pollutant types. * Groundwater discharge monitoring: Because these surveys are likely to take place over areas with easily-identified ground-control points (GCPs), the high costs associated with high-precision georeferencing payloads may not be necessary for UAS use by agencies charged with these missions. In the case of local-scale missions of this profile, LASE UAS equipped with visible-spectrum or IR payloads (for nocturnal surveys) may be used. * Mine surveys: Operation inside small, confined areas without GPS coverage make VTOL and MAV or NAV UAS a likely choice for enclosed mines, while larger LASE or VTOL with exotic payloads (e.g., LIDAR, RADAR) can be envisaged to improve surveys and operations in open-pit mines.