Abstract: Remote monitor and control of an airfield lighting system. A processing system local to the airport is provided in communication with the airfield lighting system for monitor and control thereof, the airfield lighting system producing airfield information for processing by the local processing system. The local processing system connects to a global communication network such that the airfield information is accessed from a remote location disposed on the global communication network.

Abstract: A method and system for visually guiding an aircraft in its landing approach to a runway having an approach area equipped with approach lights operable in off, low, medium, and high intensity states. The lights are communicated with a secondary side of a transformer, which has a primary side with low, medium, and high taps that correspond to the light states. Off, low, medium, and high lighting intensity requests correspond to the low, medium, and high states of the plurality of lights. AC power is switched between the transformer taps in response to a request for an increase in lighting intensity. Power is sequentially applied to the taps by supplying the power to the low tap for a first predetermined time interval before supplying the power to the medium tap.

Abstract: A method and system for locating aircraft with respect to airport runways selecting as a function of aircraft state parameters one of a plurality of candidate runways that the aircraft on which it is installed is most likely to encounter, whether taxiing, preparing for take-off, or approaching to land.

Abstract: A method and system for visually guiding an aircraft in its landing approach to a runway having an approach area equipped with approach lights operable in off, low, medium, and high intensity states. The lights are communicated with a secondary side of a transformer, which has a primary side with low, medium, and high taps that correspond to the light states. Off, low, medium, and high lighting intensity requests correspond to the low, medium, and high states of the plurality of lights. AC power is switched between the transformer taps in response to a request for an increase in lighting intensity. Power is sequentially applied to the taps by supplying the power to the low tap for a first predetermined time interval before supplying the power to the medium tap.

Abstract: A runway lighting fixture of the type normally permanently installed at an aircraft installation such as an airport to provide visible light signals to an aircraft, the fixture having an internal, non-visible light source such as an infrared lamp capable of being activated to provide a non-visible light signal to an aircraft specially equipped to see such non-visible signals. An airport normally having arrays of permanent visibly-lighted fixtures can be equipped for long-term or permanent covert operations capability by installing covert, non-visibly-lighted fixtures in place of visibly-lighted fixtures. In a preferred form the covert fixtures are capable of being both visibly and non-visibly lighted to allow normal appearing non-covert operations at the airport, and unobtrusive covert operations whenever needed.

Abstract: A guidance system guides a driver to drive a service vehicle, such as a baggage loading vehicle, into a prescribed parking position adjacent to an aircraft without colliding with the aircraft. The guidance system includes at least two indicator markers, preferably marker lights, arranged spaced apart from one another on the aircraft. The two markers present a prescribed visual pattern, e.g. an alignment of the two markers, along a line of sight defining a safe approach path. If the driver steers along this safe approach path so that he sees the prescribed visual pattern of the markers, then a collision between the vehicle and the aircraft will be avoided. Alternatively, a projector projects a light pattern such as a projected boundary marker line onto the ground surface adjacent to the aircraft to mark a safe collision-free approach path.

Abstract: A method for locating aircraft with respect to airport runways and taxiways, generating and annunciating situational awareness advisories as a function of aircraft state parameters relative to a determination of the aircraft location.

Abstract: An airfield guidance sign. The sign 100 (of FIG. 1a) includes a case (102), a multi-element light source (114) attached to the case (102) for providing light interior to the case (102), a light dispersion subsystem of the case for dispersing the light from the light source (114) substantially uniformly throughout the interior of the case (102); and a side panel (126) forming a side of the case (102) for displaying information.

Abstract: A hazard avoidance system for a vehicle utilizes data related to a location of a collision threat, conditions at the location, and vehicle operating parameters to select a light illumination routine that is optimal to attract the attention of and repel a collision hazard.

Abstract: The present invention involves a lighting control module for at least one aviation obstruction light including a microcontroller, and switching means for selectively coupling the aviation obstruction light to a power source, the microcontroller coupled to the switching means and selectively activating the aviation obstruction light. The microcontroller has programming for sensing a master light controller such that if a master light controller is sensed, then the microcontroller coordinates activation of the aviation obstruction light with the master light controller, and if a master light controller is not sensed, then the microcontroller sends activation signals as a master light controller.

Abstract: A flight guidance system providing perspective flight guidance symbology using positioning and terrain information provides increased pilot situational awareness of an aircraft. The guidance system uses a positioning system and a detailed mapping system to provide a perspective display for use in an aircraft. A Perspective Flight Guidance (PFG) symbology set is thereby displayed on a pilot display. The PFG symbology set includes broken line symbols representing an open tunnel and providing flow field data, a half-bracket symbol to indicate that the aircraft is no longer in the open tunnel represented by the broken line symbols and a quickened flight path vector (QFPV) symbol to provide the pilot with predictive flight path information.

Abstract: An aircraft FMS/guidance system which provides for automated and immediate calculation of a preferred flight path and full heading, pitch-and-roll guidance along that path for paths of random origins, such as during late-occurring missed approaches and circling-to-land maneuvers.

Abstract: A barricade system includes supports positioned in a spaced-apart fashion across a path to be closed. A lightable rope is fastened to the supports to close the path to vehicular traffic. The lightable rope is energizable by a single electrical power source such as a generator or an electrical outlet. The components of the system can be stowed and transported on a trailer or the like, making the system very portable. The barricade system is particularly suited for use in closing airport taxiways, in which case it warns pilots that a taxiway is closed and prevents entry onto the taxiway. The entire system (or at least those parts of it that are placed on the taxiway) also is sufficiently frangible to permit its use as a taxiway barricade system.

Abstract: Aircraft piloting system, at least for piloting the aircraft during a non precision approach with a view to a landing.

Abstract: Techniques are described for monitoring runway occupancy and providing an indication of occupancy of a runway to an airplane on final approach the runway. A system, for example, defines and monitors one or more zones on the runway to determine whether the runway is occupied. Such a system includes sensors, such as inductive loop sensors, that may be located proximate to or on the runway, and the system may monitor ingress and egress of objects, such as airplanes or other vehicles on the ground, into and out of the zone in order to determine whether the zone is activated. The sensors may be located at points of entry and exit for the zone. The zones may be located at take-off hold areas of the runway and intersections of the runway with taxiways. A ground-based approach light array of the system may provide the indication of runway occupancy to the airplane.

Abstract: An airport feature display system for aircraft provides visual guidance cues and awareness to track the specified taxi path on a HUD. The guidance cues include symbology representative of the position of selected airport features such as runway and taxiway edges, taxi routes, and airport signage. Data representative of the airport features is communicated between aircraft systems using a data interchange method that facilitates efficient throughput of the large quantities of data required to represent the airport features.

Abstract: An integrated surface moving map advisory system that provide selectable amounts of simplified airport layout information, simultaneously with authorized ground movement authority in order to provide highly informative and intuitive guidance with respect to all aspects of operating an aircraft or other vehicle in a controlled geographical area. The advisory system may be further enhanced by the additional overlay of symbols representing other airport traffic along with the general intentions of such traffic.

Abstract: A method for automating a landing maneuver for an aircraft, comprising the steps of generating an approach profile comprising an initial approach fix (IAF), a flight path, a landing decision point, a balked landing route, a pre-landing point, and a landing point, engaging an automated approach system to access the approach profile, receiving periodic position data of the aircraft, comparing the position data to the approach profile to compute a plurality of deviations each time the position data is received, outputting the plurality of deviations to a display, converting the plurality of deviations into a plurality of control commands, and maneuvering the aircraft in response to the control commands along the flight path.

Abstract: A method and system for determining a desired altitude for an aircraft during descent toward a runway is provided. The method and system utilize latitude and longitude data provided by a global positioning system (GPS) as well as coordinate data concerning the location of a touchdown point. Elevation data concerning the elevation above mean sea level of the touchdown zone of a runway on which the aircraft is to land is utilized in the exemplary embodiment. The method and system of the invention determine a desired altitude for the aircraft without regard to the actual altitude of the aircraft. Instead, the data utilized provide a pilot with recommended altitude data that can be used to maintain a course of approach to the runway at a prescribed angle.

Abstract: In an arrangement for supervising and controlling field light units (20) at an airport, a regulator provided with a monitoring unit for power supply and for monitoring the light units is arranged individually for each light unit (18,20) to regulate the light intensity of the light units and to receive information as to their operational status. In a preferred embodiment, each light unit comprises two separate light sources that can be alternately and separately connected into circuit in case of failure to either of the light sources. Each light unit is provided with an electronic unit including a regulator, monitoring unit, and modem for power supply to the light unit and for monitoring the operation of the light unit. Each light unit is individually addressable from a control central for the airport. A ground traffic control system can be integrated into the field lighting system by connecting suitable presence detectors to the system.

Abstract: A ground traffic control system for use in controlling the movement of an aircraft and various other vehicles on the grounds of an airport. The system and methodology involve, with regard to aircraft, the precursor transmission of a full packet of travel-route information (routes and waypoints) that is sent, according to operation of the system, as a singularity just prior to controlled travel of an aircraft. Portions of assigned travel routes that are based upon an assembly of waypoint-to-waypoint data are clearly communicated to an aircraft crew, including communication via specific visual mapping data, and are armed with the capability of informing a crew visually exactly where it is in relation to assigned travel instructions. Similar methodology, enabled similar system structure, is used for the control of other airport-related vehicles.

Abstract: A Terrain Following Apparatus for a vehicle such as an aircraft includes means (1) for effecting autonomous following of terrain by the vehicle, a control device (2), operable by a person operating the vehicle, to engage and disengage the means (1), a Terrain Referenced Navigation system (3) operable to provide navigation data for the vehicle, and validation means (4) for validating the integrity of the navigation data to provide when the integrity of the navigation data is validated for engagement of the autonomous Terrain Following means (1) by the device (2) and when the integrity of the navigation data is invalidated, for preventing operation of the means (1) when the control device (2) is operated.

Abstract: A positioning and proximity warning method for vehicle includes the steps of outputting global positioning system signals to an integrated positioning/ground proximity warning system processor; outputting an inertial navigation solution to an integrated positioning/ground proximity warning processor; measuring air pressure, and computing barometric measurements which is output to the integrated positioning/ground proximity warning processor; measuring time delay between transmission and reception a radio signal from a terrain surface, and computing radio altitude measurement which is output to the integrated positioning/ground proximity warning processor; accessing a terrain database for obtaining current vehicle position and surrounding terrain height data which is output to the integrated positioning/ground proximity warning processor; and receiving the position, velocity and time information or said pseudorange and delta range measurements of said global positioning system, the inertial navigation solution

Abstract: Remote monitor and control of an airfield lighting system. A processing system local to the airport is provided in communication with the airfield lighting system for monitor and control thereof, the airfield lighting system producing airfield information for processing by the local processing system. The local processing system connects to a global communication network such that the airfield information is accessed from a remote location disposed on the global communication network.

Abstract: A flight control system and method for controlling a circle-to-land (“CTL”) maneuver utilizes an airborne area navigator. The area navigator receives inputs on aircraft category, aircraft position and speed, airport navigation data and pilot supplied data. In response to this data, the area navigator calculates the necessary conditions for executing the CTL maneuver and outputs control commands to a flight director. The pilot then executes the CTL maneuver either manually using the information provided by the area navigator or by using the aircraft autopilot under the direction of the flight director.

Abstract: A method for generating a horizontal path for the avoidance of danger zones for an aircraft. The method models the contours of each danger zone by a succession of segments demarcated by points. The method determines two homing circles and two capture circles passing respectively through the initial point and final point which are tangential respectively to the initial route and to the final route and have respectively the initial and final turning radius. The method also determines tangents both to the homing circles or the capture circles and to the contour of each danger zone. Among these tangents, a pair of tangents to a homing circle and to a capture circle are selected, defining a path skeleton connecting a homing circle to a capture circle without meeting a danger zone. And, an automatically controllable evasion path that lies on the previously defined path skeleton is then determined.

Abstract: A self contained electronic system for manual or automatic control and navigation of fixed winged aircraft using electronic position sensing such as GPS, DGPS, WAAS, and the like, as the primary sensor and making use of known flight characteristics of the aircraft to determine aircraft attitude without any interaction with the aircraft, its controls, or the outside environment and without any moving mechanical devices other than switches, dials and connectors. The automatic and visual interface between the system and the pilot provides for simplified flight controls, and a new solution to the hazard of disorientation, and will reduce the time needed for a pilot to become proficient in VFR and instrument flying. A single instrument replaces many of the conventional instruments used for flight. Navigation data is provided in an easy to understand graphical format. The pilot is told explicitly where to move aircraft controls.

Abstract: A system, method, and computer program product for alerting an aircraft flight crew of an inconsistency during an instrument landing system (ILS) approach to a selected runway. The system includes a component configured to receive glideslope and localizer signals, and a component configured to determine aircraft approach angle to runway end. Also, a component configured to alert the aircraft flight crew of an approach inconsistency, if the determined aircraft approach angle to runway end is less than a threshold angular value and one or more parameters based on aircraft position and the received glideslope and localizer signals are met. The component configured to determine aircraft approach angle to runway end determines the aircraft approach angle to runway end based on aircraft geometric altitude, a vertical figure of merit, a horizontal figure of merit, runway elevation, and aircraft distance to runway threshold.

Abstract: An aircraft including an approach and landing system, including a navigation unit for providing navigation information, a weather radar unit for providing radar information, a processor which receives navigation information from the navigation unit and information from the weather radar unit, the processor unit providing an output representing information concerning the aircraft in accordance with the provided navigation information and radar information, a memory for storing information representing a scene, the processor unit correlating the stored scene information with the output representing information concerning the aircraft to provide a mapped scene, a display unit for displaying the output of said processor and the mapped scene, and a steppable frequency oscillator for providing a signal which is stepped in frequency to the weather radar unit, thereby providing an increased range resolution.

Abstract: FAA regulations mandate that a pilot must have sufficient visibility to see the airport, and then the runway before landing; and sufficient visibility to see a substantial portion of the runway before taking off. In adverse weather conditions when visibility is reduced flights are cancelled, delayed, and rerouted to land where visibility is adequate. Poor visibility is one of the major causes of air traffic fatalities. One aspect of this invention discloses a method of illuminating an aircraft landing location to facilitate identification and aircraft guidance thereto comprising the following steps: projecting a laser beam upwardly from the location so that an aircraft may be better able to target the landing location particularly in conditions of poor visibility.

Abstract: A power-line carrier airport facilities monitor system, comprising a host station and respective terminal for monitoring individually the object facilities via a rubber transformer are connected in series to a power line derived from a fixed current generator, wherein the host station and respective terminal create a control command for respective terminal/monitoring signal of the object facilities as text data and, on the other hand, injections said text data to the power line by FSK modulation based on the zero cross detection of the power line power source waveform.

Abstract: The present invention provides several apparatus, methods, and computer program products for predicting which one of at least two candidate runways on which an aircraft is most likely to land, such that data concerning the predicted runway may be used by ground proximity warning systems. The present invention includes a processor that receives data pertaining to an aircraft and at least two candidate runways in close proximity to the aircraft. Based on this data, the processor of the present invention determines a reference deviation angle between the aircraft and each candidate runway. This reference deviation angle may represent a bearing, track, or glideslope deviation angle between the aircraft and each candidate runway. The processor further evaluates each of the reference deviation angles and predicts which of the candidate runways the aircraft is most likely to land.

Abstract: The present invention relates primarily to an aircraft approach and landing system using passive retroreflective panels strategically placed along both sides of a landing strip or runway. The retroreflective panels comprise pairs of color-coded orange panel markers indicating the touchdown zone and singly, the remainder of the landing strip. The array of reflective elements are placed adjacent to the runway path so that the array produces a left/right reflected beam envelope within which an aircraft may be centered in order to maintain a desired landing vector. Upon installation of the reflector panel elements, each panel can be tilted with respect to the runway surface at an angle corresponding to the glide slope to produce a visual reflective beam aligned to the desired glide slope angle.

Abstract: Weather information is stored in a weather information storage unit. Information of aircraft flight situation, flight plan, air traffic flow management, and condition status is stored in an aircraft information storage unit. On the basis of information stored in the weather information storage unit and the aircraft information storage unit, arrival time of each arriving aircraft and departing aircraft is predicted by an arrival time prediction unit and a departure time prediction unit. The information of the estimated time thus predicted is stored in an estimated time of takeoff and landing storage unit. On the other hand, on the basis of information stored in information storage units, runway use time is assigned to each arriving aircraft and departing aircraft by a takeoff and landing assignment unit in accordance with Control System Standards. Runway reservation information thus obtained is stored in a reservation information storage unit.

Abstract: Man-machine interface (MMI) for airport traffic control purposes, in particular for safe taxiing and/or approach-departure control at an airport, having a display area on which processes and states at the airport, for example the movements and the current position of aircraft, the switching state of lighting systems, etc., can be displayed and influenced. The display area is designed with a screen whose diagonal is more than 19 inches, preferably more than 21 inches.

Abstract: The present invention relates to a thermal signaling device. The signaling device generally comprises a container including a thermal emitting surface and an interior space, and at least one heat source disposed within the interior space of the container. In operation, the heat source is activatable to heat the thermal emitting surface such that the thermal emitting surface can be detected by a thermal sensing system.

Abstract: An air vehicle landing/takeoff area mapping system includes a plurality of transmitters located in the landing/takeoff area with each transmitter propagating a signal having a signal frequency indicative of the transmitter location. A receiver is located on the air vehicle and is capable of scanning the landing/takeoff area. The receiver processes a received transmitter signal to produce an output based on the received transmitter signal frequency. Control logic processes a sequence of receiver outputs to produce an image of the landing/takeoff area on a display device located within the air vehicle to assist a pilot during landings and takeoffs of the air vehicle under either clear or inclement weather conditions and/or either day time or night time visibility.

Abstract: An image processing apparatus and method for identifying a safe landing location on the surface of the moon or planets calculates local average brightness and brightness variance in a neighborhood of each image pixel based on a digital image data obtained with a camera and determines whether each pixel represents a level and flat area based on the local average brightness and brightness variance calculated for each pixel, thereby extracting a desirable landing site.

Abstract: An imaging apparatus for aiding landing of aircraft in weather conditions obscuring a pilot's view of a runway. The apparatus comprises a plurality of LED assemblies which are disposed along the runway. Each LED assembly includes a plurality of LEDs, a receiver and a plurality of drivers responsive to the receiver for energizing the LEDs. The LEDs of each LED assembly are pulsed on by signals from a transmitter disposed adjacent an end of the runway. The transmitter also sends synchronization signals to a receiver located on board the approaching aircraft. The receiver on the aircraft is coupled to a processor which uses the synchronization signals to determine when the LEDs are energized and when they are not energized. The processor controls a CCD camera mounted on the aircraft so as to obtain an unobstructed view of the approaching runway. The processor controls the CCD camera such that the camera takes images (i.e., frames) while the LEDs are pulsed on and also while the LEDs are off.

Abstract: An electrical strip of infrared radiating elements which is powered by a battery and rolled up on a wheel and has many advantages over the present device. The first is visibility. It is highly visible at over three miles and the system is a 3/4" strip with LEDs placed every meter and on both sides that is rolled up on a reel. To deploy the marker the strip can be staked or held at one end while the strip is simply unrolled of the reel. The PIRM is self packing and, if packaged to do so, can automatically roll itself up. The PIRM can be operated either by a switch on the reel or remotely, by laser remote control or by a switch on the reel. The flashing pattern is completely programmable. The pattern can be used as a wind direction indicator. The speed it flashes can be used to indicate how hard the wind is blowing or how dangerous the landing zone is.

Abstract: A microprocessor-controlled airfield lighting control and monitoring system having bi-directional communication between the controlling microprocessor and the airfield lights and/or sensors. The system also includes a metal container for the remote control microprocessor and an improved attachment arrangement for the power transistor associated therewith. A DC power supply is connected to the remote controller microprocessor and has an integrated circuit adapted to sense a threshold voltage, which causes the power transistor to short around the associated power source.

Abstract: A window-passage detection system has a ground system comprising: a first course generator (3) for generating a horizontal DDM (Differential Depth of Modulation) pattern for defining a horizontal width (25) of a virtual window frame by emitting a first carrier signal and a first side-band signal from a pair of first transmission antennae (6a and 6b), a second course generator (4) for generating a vertical DDM pattern for defining a vertical width (26) of the virtual window frame by emitting a second carrier signal and a second side-band signal from a pair of second transmission antennae (7a and 7b), and a third course generator (5) for generating a longitudinal DDM pattern for defining a longitudinal position (27) of the virtual window frame by emitting a third carrier signal and a third side-band signal from a pair of third transmission antenna (8a and 8b). Pairs of the first to the third transmission antennae (6a to 8b) generate three orthogonal polarization planes.

Abstract: A wake turbulence avoidance light system is provided including an aircraft runway with a periphery including a pair of long parallel side edges and a pair of short end edges. Also included is a plurality of light assemblies mounted along at least one of the side edges of the runway in spaced relationship. A plurality of sensors are adapted for indicating a point on the runway at which a plane has departed. Finally, control circuitry is connected between the light assemblies and the sensors for indicating a location of the point by illuminating a light assembly adjacent thereto, as detected by the sensor.

Abstract: An aircraft local-area augmentation system that employs a differential global positioning system (GPS) to assist aircraft (102) landing is disclosed. One or more GPS ground stations (120), each including at least two GPS receivers (122) and a datalink transmitter (126), calculate and transmit GPS correction data to an aircraft (102). An aircraft (102) employs a GPS receiver (106) for receiving ranging signals (112) from GPS satellites (108), and a datalink receiver (116) for receiving GPS correction data and other information from a GPS ground station (120). The aircraft (102) further includes a data processor (110) for determining a global position of the aircraft (102) as a function of the aircraft GPS pseudorange data and the GPS correction data. The system minimizes the introduction of non-common errors by the use of double-differencing calculations using multiple combinations of satellite (108) and GPS ground station receiver (122).

Abstract: A system for annunciating traffic information includes a plurality of stationary transmitters (42,46) for generating relatively short range, highly directional beam signals (44,48) containing a burst data stream signal (10) to each of a plurality of mobile receivers (50,52,54). The stationary transmitter (42) includes a transmitter (42a) connected to a transmitter antenna (56) for generating the beam signal (44) and to a transmitter control (60) which is connected to a transmitter memory (68) for storing a plurality of compressed data voice messages which are read by the transmitter control and generated as data packet signals (16,20,22) in the burst data stream signal (10).

Abstract: A marker comprises a metal sheet bent to curve about an axis and forming, in sector perpendicular to said axis a hairpin turn and where there are median extents on each side, approximating in the sheet planar panels, defining an angle of 0.degree.-30.degree. to each other and having on their convex side, a retroreflectant layer.

Abstract: The present invention includes an airfield lighting and control system for energizing at least one airfield control device and containing a ground fault detection system, comprising: (1) at least one airfield control device; (2) an AC electrical circuit conducting an AC signal and connected to said at least one airfield control device; (3) an inductive device, in electrical contact with said AC electrical circuit, which comprises (a) an inductive coil having an input pole and an output pole, and being loaded by a capacitor; (b) a driver winding for the inductive coil, the driver winding adapted to sense AC current flow through the inductor coil; (c) a sampling resistor connected to the driver winding and adapted to detect AC current in the form of a voltage across the sampling resistor; (d) signal processing circuitry comprising: (1) an inverting amplifier adapted to amplify the voltage; and (2) a phase shifter adapted to shift the phase of the voltage; and (e) a power amplifier connected to the signal proces

Abstract: A differential ground station repeater in which a plurality of transmitters are utilized to relay information to an aircraft from a single ground station situated to receive satellite information and to transmit the satellite and other information to the plurality of correction transmitters in which the transmitters utilize a single frequency but transmit at different described sub-time slots so that the aircraft may utilize the signal of any of the transmitters it may be receiving signals.

Abstract: A control system includes at least one guiding device including a long range guiding water jet generator having a plurality of first nozzles each projecting a jet of water upwardly and a first illumination apparatus projecting a plurality of beams of light upwardly each in concert with the jet of water projected from each of the first nozzles so as to guide the flight vehicle along a predetermined direction when the flight vehicle is located at a longer distance relative to the guiding device and a short range guiding water jet generator having a plurality of second nozzles each projecting a jet of water upwardly and a second illumination apparatus projecting a plurality of beams of light upwardly each in concert with the jet of water projected from each of the second nozzles so as to guide the flight vehicle along the predetermined direction when the flight vehicle is located at a shorter distance relative to the guiding device.

Abstract: A method for automatically providing weather advisories for an airport to pilots comprises monitoring weather conditions at the airport and then generating weather advisories in response to these weather conditions. The broadcast traffic on a common traffic advisory channel is also simultaneously monitored and then menus providing for selectable weather advisories and radio check options are broadcast to the pilots. The weather advisories or radio check can then be selected by the pilot by clicks of their transmit button. The time spacing between the menus is adaptively changed in response to traffic on the common traffic advisory frequency. Also, the length of the weather advisories is also changed in response to this traffic. The radio check option is provided automatically by first confirming selection of the radio check option and then allowing the broadcaster to broadcast a short message which is recorded by the system and then rebroadcast.