Abstract:
A method and system for enhancing situational awareness in a rotary wing aircraft, includes receiving signals indicative of environmental information for the aircraft during a hover; determining signals indicative of a heading, course, and speed for the aircraft in response to the receiving of the environmental information; and displaying a composite symbology for heading, course, and speed on tactical display.

Description:
FIELD OF THE INVENTION 
     The subject matter disclosed herein relates generally to the field of instrumentation for an aircraft and, in particular, to an integrated tactical navigation plot that provides augmented symbology cueing to a pilot in a rotary-wing aircraft. 
     DESCRIPTION OF RELATED ART 
     Typically, tactical navigation displays or plots on rotary-wing aircraft such as multi-mission helicopters provide information on a North Upward display to detect and track subsurface or surface contacts at sea utilizing sonar technology, with north being upward or at the top of the navigation display. Dipping sonar fitted to a range of multi-mission helicopters allows the helicopter to protect shipping assets from submarines or surface threats. In an example, these aircraft can drop active and passive sonar devices (sonobuoys) to determine the location of hostile submarines. However, in a multi-mission helicopter, heading and course at slow speeds are independent and can differ significantly. Information presented in North Upward requires mental rotation to re-align the information to the observer&#39;s operating orientation, which is Head Up. This mental rotation is a skill refined in experienced navigators. In times of high workloads, this re-alignment may cause confusion, especially on southerly courses. A pilot, during a mission, has to determine the helicopter&#39;s heading and course, determine a course of a weapon deployed from the helicopter, and determine a heading of other ships in the vicinity through various instrumentations in the cockpit and mental calculations. A tactical plot that that provides a helicopter&#39;s heading and course in relation to other vehicles in the water and which is significantly lower in complexity would be well received in the art. 
     BRIEF SUMMARY 
     According to one aspect of the invention, a method for enhancing situational awareness in a rotary wing aircraft comprises receiving, with a processor, signals indicative of environmental information for the aircraft during a hover; determining, with the processor, signals indicative of a heading, course, and speed for the aircraft in response to the receiving of the environmental information; and displaying, with the processor, a composite symbology for heading, course, and speed on a tactical display. 
     According to another aspect of the invention, a system for enhancing situational awareness in a rotary wing aircraft includes one or more sensors configured to receive signals indicative of environmental information for the aircraft during a hover; a computer operably connected to the one or more sensors and configured to: receive signals indicative of environmental information for the aircraft during a hover; determine signals indicative of a heading, course, and speed for the aircraft in response to the receiving of the environmental information; and display a composite symbology for heading, course, and speed on a tactical display. 
     According to another aspect of the invention, a rotorcraft includes an airframe; a main rotor disposed at the airframe, the rotor including a plurality of rotor blades; and a tactical display system for displaying screen symbology for the helicopter including: one or more sensors configured to receive signals indicative of environmental information for the rotorcraft during a hover; a computer operably connected to the one or more sensors and configured to: receive signals indicative of environmental information for the aircraft during a hover; determine signals indicative of a heading, course, and speed for the aircraft in response to the receiving of the environmental information; and display a composite symbology for heading, course, and speed on a tactical display. 
     Technical effects of the invention relate to a tactical navigation display that significantly lowers complexity of displaying heading and course of a rotary wing aircraft in relation to neighboring surface or subsurface contacts. 
     Other aspects, features, and techniques of the invention will become more apparent from the following description taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which like elements are numbered alike in the several FIGURES: 
         FIG. 1  is a perspective view of an exemplary aircraft for use with embodiments of the invention; 
         FIG. 2  is a system architecture block diagram according to an embodiment of the invention; 
         FIG. 3  is a tactical plot displaying symbology for an aircraft according to an embodiment of the invention; and 
         FIG. 4  is a detail of symbology of  FIG. 3  according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings,  FIG. 1  illustrates a general perspective view of an exemplary vehicle in the form of a vertical takeoff and landing (VTOL) rotary-wing aircraft  100  for use with embodiments of the invention. In an embodiment, the aircraft  100  uses a tactical symbology algorithm  208  ( FIG. 2 ) for displaying, in an example, aircraft  100  heading, course, and speed as well as target vehicles in a NORTH-UPWARD tactical display. As illustrated, rotary-wing aircraft  100  includes an airframe  102  having a main rotor assembly  104  and an extending tail  106  which mounts an anti-torque system, such as a tail rotor assembly  108 . In embodiments, the anti-torque system may include a translational thrust system, a pusher propeller, a rotor propulsion system, or similar. The main rotor assembly  104  includes a plurality of rotor blades  110  mounted to a rotor hub  112  that rotates about axis A. Also, tail rotor assembly  108  includes a plurality of rotor blades  116  that rotates about axis B, which is orthogonal to the plane of rotation of blades  116 . Main rotor assembly  104  and tail rotor assembly  108  are driven to rotate by one or more engines  114  through one or more gearboxes (not shown). Although a particular helicopter blade is illustrated and described in the disclosed embodiment, parts and spars in other configurations and/or machines, such as high speed compound rotary wing aircraft with supplemental translational thrust systems, dual contra-rotating, coaxial rotor system aircraft, tilt-rotors and tilt-wing aircraft, fixed wing aircraft, wind-turbines as well as composite primary structures designed to take fatigue cycling loads, regardless of dynamic, quasi static, or static loading will also benefit from embodiments of the invention. 
       FIG. 2  illustrates a system  200  for an architecture that is used to implement the embodiments described herein. The system  200  uses a symbology algorithm  208  in order to display one or more symbologies for heading, course, and speed on a tactical display  216 . In control system  200 , sensor data from one or more sensors  206  that are located on helicopter  100  provide navigation computer  202  with information such as pitch and/or roll angular velocities, pitch and/or roll angular accelerations, vertical acceleration, airspeed, air density, or the like in order to provide state information for aircraft  100 . In an example, sensors  206  provide environmental information on aircraft  100  during a hover to navigation computer  202 . Also, active or passive sensors  204  such as, sonars or sonobuoys provide sonar information to detect and track subsurface or surface contacts for display on tactical display  216 . In addition to the features described above, sensors  204  can include RADAR, Sonar, or the like to identify other information in the vicinity of aircraft  100 . This information for other aircraft, ships, and submarines may be displayed on display  216 . These may be displayed through sensor  204  detection or entered via manual entry or radio link for display on pilot display  216 . Navigation computer  202  communicates with sensors  206 ,  204  to analyze the data with algorithm  208  and plot it in an efficient symbology format for pilot display  216 . In an embodiment, navigation computer  202  includes a memory  210 . Memory  210  stores symbology algorithm  208  as executable instructions that are executed by processor  212 . The instructions may be stored or organized in any manner and at any level of abstraction, such as in connection with the execution of symbology algorithm  208 . The algorithm  208 , when executed by processor  212 , enables navigation computer  202  to perform the features of the invention as discussed herein. Processor  212  may be any type of processor (CPU), including a general purpose processor, a digital signal processor, a microcontroller, an application specific integrated circuit, a field programmable gate array, or the like. Also, in embodiments, memory  210  may include random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic or any other computer readable medium onto which is stored the symbology algorithm  208  described below. 
     In an embodiment shown in  FIG. 3 , aircraft symbology  302  for aircraft  100  and other vehicle symbology  304 - 312  are depicted in a North-upward representation on a tactical plot  216 . In another embodiment, a Heads-up or heads-down representation can also be presented in lieu of North-upward representation. Tactical plot  216  ( FIG. 2 ) can depict symbology information for aircraft  100  and information on other remote surface or subsurface naval vessels that are acquired from one or more sensors  204  in relation to location of aircraft  100 . In an example, aircraft  100  may acquire sensor information from other vehicles by hovering at a defined or predetermined location and lowering sensors  204  such as, for example, a sonar array tethered to aircraft  100  through a sonar cable. During the hover, the aircraft  100  monitors cable angle in case current in the water drags the sonar array through the water. The helicopter  100  will drift with the current in order to maintain a fixed cable with the sonar array. In an embodiment, heading and course of aircraft  100  can be different as the aircraft  100  drifts in the water. Aircraft symbology  302  is depicted on tactical plot  216  with heading, course, and speed. Other vehicle symbology  304 - 312  can include an elongated line associated with the respective symbology  304 - 312  to represent course of each naval vehicle associated with the other vehicle symbology  304 - 312 . With reference to  FIG. 4 , aircraft symbology  302  is symbolized by a generally “arrow-head” shaped symbol  402  circumscribed by or inscribed in a circle  404  and an elongated line  406  that extends radially from the circle  404  having a length  408 . In an embodiment, symbol  402  represents the same direction as aircraft heading, elongated line  406  indicates direction of motion or course of aircraft  100  in the direction of travel of aircraft  100 , and the length of elongated line  406  indicates speed of aircraft  100  in the direction of travel. The speed of aircraft  100  can also be represented numerically as a number  410  at an end of elongated line  406 , either in addition to or in lieu of the length of elongated line  406 . As aircraft  100  drifts with the water, additional symbology for other vehicles identified in the water with sensors  204  ( FIG. 2 ) may be depicted on tactical plot  216 . In response to the symbology on tactical display  216 , aircraft  100  may deploy armaments in the location of the other naval vehicles indicated by their relative location to aircraft  100  as depicted through other vehicle symbology  304 - 312 . 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. While the description of the present invention has been presented for purposes of illustration and description, it is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications, variations, alterations, substitutions or equivalent arrangements not hereto described will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. Additionally, while the various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.