Presence of a CAT sensor
Sensor parameters
Object names for the aircraft and their call signs
Aircraft waypoint follow mode (i.e., time, speed, or command)
Aircraft timing error tolerance to be used in modeling aircraft dynamics
Pointers to the initial Communication Channel and Surveillance agents
Spatial error tolerance - to be used in identifying the aircraft position with reference to waypoints, sector boundary intersections, and turbulence penetration points
Route that the aircraft is to follow. A route is a list of waypoints; a waypoint is a four-dimensional point composed of the latitude-longitude ground coordinate, a flight level altitude, and time or speed of the aircraft at that point (depending on the follow mode).
Aircraft are created at random, based on a route-specific exponential distribution of interarrival times, with the mean interarrival time and the minimum time separation provided by the user. If the random time generator returns an aircraft creation time that is less than the minimum separation from the previous aircraft, the minimum separation time is used instead. Route-specific interarrival time distributions were derived from the recorded data on a sampled day (described in Chapter III). The same flight schedule is used in all replications and cases.
The first and last waypoints of each route are located in the upstream/downstream sector; all other waypoints are in the subject sector. Each flight is injected at the first waypoint of its route, i.e., inside the upstream/downstream sector, and terminates at its route's last waypoint, i.e., back in the upstream/downstream sector. For demonstration purposes, no aircraft type distinctions are made and all flights are given an initial cruise speed of 470 knots, which may change later in the simulation upon instruction from the subject sector's controller.
RandomACGen can specify only one route for all aircraft it creates; therefore, there is a RandomACGen agent for each route on which aircraft are to be simulated. In two hours of simulated time in the present demonstration, there are about 80 aircraft flying on 38 routes through the subject airspace sector. The total flight time simulated for a flight depends on the length of its route and any speed or altitude changes it experiences during its transit of the subject sector. Flight times in a base (no CAT) case range from 15 minutes to 30 minutes with a mode of approximately 20 minutes.
An Aircraft agent is modeled with six-degrees-of-freedom flight dynamics to follow the waypoints of its assigned route, using the RFS waypoint following aircraft agent (AircraftOnRoute). AircraftOnRoute objects follow from one waypoint to the other, adjusting heading, speed, and altitude (i.e., changing its waypoint list) as required. The Aircraft reports its position, speed, and heading to its Flight Crew and to the Surveillance agent. It also reports to the Flight Crew the severity (light, moderate, or severe) of any turbulence it experiences during its flight.
For this demonstration, the flying and non-flying pilots are modeled as a single RFS Flight Crew agent for each Aircraft. A Flight Crew controls its Aircraft with speed and altitude change instructions; route changes are possible but not implemented in this demonstration model. The Flight Crew also receives alerts from the Sensor on the presence of moderate or severe CAT. Through its sector's Communication channel agent, a Flight Crew sends messages to and receives messages from the sector Controller.
When a CAT is experienced, a relevant PIREP is overheard, or a sensor alert is received, the RFS Flight Crew agent calls upon the MIDAS Flight Crew agent to simulate at greater fidelity the human performance of the tasks required to respond to these events (as described in detail in Chapter V). For computational efficiency and tractability, a single MIDAS Flight Crew model is used to simulate the human behavior of all RFS Flight Crews that need the greater fidelity. MIDAS internally keeps straight the messages and task loadings pertinent to each Flight Crew it is simulating. This approach also avoids the problem of the transient behavior that would occur when "spinning up" a MIDAS model that was suddenly launched when a RFS Flight Crew decided it needed one.
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