## 4 Conclusion
* Precision agriculture: Monitoring of crop health and precision application of chemicals require large payloads such as pesticide/herbicide applicators and advanced E/O sensors, as well as precise navigational and maneuvering capability. Relatively small areas of operation combine to yield a preference for larger VTOL UAS in these applications. The HALE UAS remain at the upper end of the cost scale and will be available for select applications of global scale; climate, ocean and ice monitoring. These aircraft tend to be considered in situations where long duration and/or long distance requirements are essential to the success of the mission and trump concerns of operational cost. Once airspace guidelines and access issues are resolved (by the FAA in the US, for example), additional thought and evaluation will be required to locate the optimum compromise of cost versus capability for many of these unique resource applications. Continuing advances in the miniaturization of remote sensing and positioning hardware, with an eye toward their use on UAS, is placing increasingly powerful monitoring and mapping equipment on ever smaller UAS platforms. As UAS operation for peacetime uses becomes routine, we predict the evolution of multiple avenues of access to UAS for potential users. Government agencies or universities with budgets and facilities sufficient to acquire or develop and maintain UAS of their own, likely will remain among the largest users of UAS, while smaller agencies and non-governmental organizations with relationships to these groups may benefit from contributions of UAS capabilities by their larger partners. Additional availability of UAS through the acquisition of military surplus by approved users (such as government agencies) may provide some benefits through greater familiarity with UAS use and operation within these organizations, although the scientific benefits of surplus UAS in the face of such rapidly developing technology are questionable. Commercial UAS manufacturers will increasingly tailor their products to the needs of civilian clients as wartime military outlays for UAS stabilize and peacetime demand increases with regulatory clarification. Additionally, a service sector will evolve to offer UAS services such as leased systems, on-demand flights, or consultation for choosing appropriate platforms or analyzing UAS-generated data. While UAS manufacturing offers significant barriers to entry and competition from established companies, the affiliated-service sector likely will see dramatic growth in the coming decade. The potential user of UAS technology will need to carefully consider their data gathering requirements and thus, the sensors needed to carry out their mission. Sensor size, weight and power draw coupled with flight duration requirements will largely determine the minimum aircraft size acceptable for the mission. Choosing unmanned versus manned aircraft is a decision that must also be made with care. Under current cost per hour pricing, manned aircraft often offer the cheaper and more efficient alternative; however, cost is not always the only consideration in fire and disaster response. Pilot and crew safety must also be considered along with human flight limitations. UAS continue to undergo rapid technological progress, and regulatory bodies struggle to cope with this rapid evolution while balancing the economic, information, and safety needs of their constituents. The articles presented in this Special Issue showcase several of the most advanced studies and organizations utilizing UAS in the civilian sector to date. Readers whose needs may be met with UAS technology in the future should consider collaborations or consultations with these or other established UAS groups to maintain awareness of new technological advances.