## Materials and Methods
Here, four different UAS conducted simultaneous operations, with two UAS conducting extended-visual line of sight (EVLOS) altitude-stratified flight operations and two UAS conducting local operations utilizing a combination of altitude-stratified and geographically contiguous airspace. The two UAS conducting EVLOS altitude-stratified flights along the corridor (green and purple areas) simulated a pipeline survey/inspection mission. The UAS conducting low local operations at Herder Burner (blue area) simulated either a SAR mission or vegetation mapping mission, depending upon the sensor flown. The hillside mission (brown area) simulated a dinosaur fossil mapping or glacier mapping mission (both were rehearsals for actual missions to be performed later that summer). Flights accomplished included four simultaneous UAS: one sortie in high-altitude block (650-850') EVLOS along the corridor (Responder); one sortie in mid-altitude block (250-550') EVLOS along the same corridor (Matrice); one sortie in low-altitude block (0-250') stratified local airspace (Ptarmigan); and one sortie contiguous airspace (0-500') local operations (S1000). These flights were conducted in both the AM/PM time blocks using the airspace shown in Figure 11.  
Day 2 scenario (media day). This mission set included up to five different UAS conducting simultaneous coordinated geographically separated operations, 1-2 at UAF campus and 1-2 at PFRR. The AM mission at UAF included videography of the new Elvey 9 m satellite dish by a S800 Ptarmigan UAS, as well as an airborne video of the mission taken by a DJI Inspire. The PM mission at UAF involved a lakeshoe mapping of Smith Lake. The simultaneous AM mission at PFRR was the demonstration of a parachute system for multirotor UAS (S900 hexacopter). PM missions at PFRR involved an airborne SAA demonstration and Real-Time Kinematic (RTK) GPS work (S1000 octocopter). For the UTM/USS implementation, UAF selected a semicentralized approach using one UTM Point of Contact (POC) at UAF and a second UTM POC at PFRR locations. Simultaneous operations for UAF and PFRR were achieved by coordinating launch times in advance and then communicating via  
Figure 11: UAF TCL2 campaign at the Poker Flat Research Range (PFRR), May 2017. UAF assets included 1\(\times\) each Ptarmigan S800, S900, S1000, ING Responder, and DJI Matrice 100, DJI Inspire [22] (p. 10). text. Flight operations at PFRR were conducted in close proximity as shown in Figure 11. The airspace utilized for UAF site missions is shown in Figure 12A. The ACUASI Ptarmigan hexacopter performing the inspection is shown in Figure 12B. Flight activities during days 3 and 4 were similar to that of the day 1 scenario, but with varying altitude blocks and UAS involved. These days were also used for weather makeup, as both snow (even in June) and wind had often curtailed planned flight activities. UTM TCL3 campaign: The third phase of the UTM program focused on more technically complex systems, which would begin to provide increasingly automated UAS/USS system capabilities to handle the additional complexities associated with higher-density UAS traffic and interactions. NASA asked the UAS test sites to consider which aspects they would focus on for their respective efforts and used a competitive bid process, enabling NASA to spread the effort between the various entities based upon the program interests and team capabilities. Highlights from the TCL3 SoW are listed in Appendix A.  
TCL3 included a series of distributed events occurring at several UAS test sites. For this campaign, UAF changed locations for flight operations from PFRR to the grounds adjacent to the UAF's main campus. The flight airspace was divided into complex and tightly integrated geometries to increase the airspace density and UAS interaction above previous TCL2 levels. Tasks were divided into sets of major categories: (1) CNS: Communication, Navigation, and Surveillance; (2) SAA: Sense And Avoid; (3) DAT: Data and Information Exchange; and (4) CON: Concepts.