Abstract: The present invention essentially comprises a system, method, computer program and combinations thereof to utilize dual-polarization generated data generally associated with weather and non-weather events for mapping data, producing geo-referenced data, producing mosaics, generation of precipitation masks, non-precipitation mask, and classification masks in general, production of vertical cross sections and predetermined fly throughs, producing short term forecasting, prediction of specific weather phenomenon, correcting or adjusting rain gauge data as well as quantitative precipitation estimation, and combining other meteorological data to correct or adjust estimated rainfall accumulation gathered by dual-polarization radar.

Abstract: A hazard warning system can be utilized in an aircraft. The hazard warning system can include a processing system for determining a high altitude ice crystal (HAIC) condition and causing a warning of the HAIC condition to be displayed. An avionic display can be used to display the warning of the HAIC condition.

Abstract: This disclosure provides an information display device, which includes a sensor signal acquirer for acquiring a sensor signal indicating a content detected by a sensor, a signal processor for performing first signal processing and second signal processing different from the first signal processing, on the sensor signal, and a display unit for displaying on a screen image, first information of the sensor signal after the first signal processing, and partial information of second information of the sensor signal after the second signal processing in a different display mode from the first information, the partial information being different from the first information.

Abstract: The hazard warning system that included processing system for detecting a high altitude ice crystal (HAIC) condition. The aircraft warning system can use at least two types of radar returns to detect the HAIC condition. Warnings of high altitude ice crystal conditions can allow an aircraft to avoid threats posed by HAIC conditions including damage to aircraft equipment and engines.

Abstract: The present invention essentially comprises a system, method, computer program and combinations thereof to utilize dual-polarization generated data generally associated with weather and non-weather events for mapping data, producing geo-referenced data, producing mosaics, generation of precipitation masks, non-precipitation mask, and classification masks in general, production of vertical cross sections and predetermined fly throughs, producing short term forecasting, prediction of specific weather phenomenon, correcting or adjusting rain gauge data as well as quantitative precipitation estimation, and combining other meteorological data to correct or adjust estimated rainfall accumulation gathered by dual-polarization radar.

Abstract: According to one aspect of the present invention, a radar system is provided which accurately measures the surface profile in a wide sector beneath and forward of a helicopter, to aid low level transit and landing in poor visibility. This uses an electronic beam synthesis technique to form multiple beams directed at the area of interest, each measuring the distance to the first reflected signal received by each beam. These distances represent the profile of the ground and any objects on the ground. A processor then compares the measured profile with the ideal ground profile for safe landing. If the deviations from straight and level exceed the specified requirement for safe landing, or if sufficient rotor clearance is not detected, then a warning is given to the operator. A display will show the measured ground profile highlighting the unsafe regions, allowing the operator to seek a safe region to land.

Abstract: A signal processing device, which includes an echo signal input module for inputting echo signals from an antenna discharging electromagnetic waves to a predetermined area and receiving the echo signals reflected on a target object, an echo signal level detection module for detecting a level of each of the echo signals from each location within the predetermined area, a target object detection module for detecting the target object based on the levels of the echo signals, a correlation processing module for performing scan-to-scan correlation processing of a plurality of scans, and a level adjustment module for adjusting the levels of the echo signals after the scan-to-scan correlation processing. The level adjustment module adjusts the levels of the echo signals corresponding to the locations where the target object detection module detects the target object.

Abstract: A method for indicating a weather threat to an aircraft is provided. The method includes inferring a weather threat to an aircraft and causing an image to be displayed on an aviation display in response to a determination by aircraft processing electronics that the inferred weather threat to the aircraft is greater than a measured weather threat to the aircraft.

Abstract: Autonomous Underwater Vehicles (AUV) collect and transmit information about ice floe thickness; this is combined with SYNTHETIC APERTURE RADAR images from satellites to identify and track dangerously thick regions of ice. The overlayed data is presented graphically to allow tracking of the thick ice regions over time. This information is used to alert drilling platforms in icy ocean conditions of pending ice floe dangers.

Abstract: A standoff range, sense-through-obstruction radar system is capable of detecting micro-Doppler, or life form signatures, and movements through obstructions at stand-off ranges and displaying the target information over a live video feed of the area under surveillance. The sense-through-obstruction radar system comprises an antenna assembly that includes a horn antenna and a reflector configured to reflect radio frequency (RF) energy to/from the horn antenna. An antenna pointing assembly supports the antenna assembly. The antenna pointing assembly is configured to move the antenna assembly to point the antenna assembly toward an obstruction. A sensor assembly is mounted to the antenna assembly so that the sensor assembly is aligned with the RF beam formed from the RF energy reflected from the reflector to the horn antenna. The sensor assembly is configured to detect the location of the obstruction and to provide information to assist pointing of the antenna assembly toward the obstruction.

Abstract: Systems and methods for on-the-fly characterization of an arbitrary array of antenna elements are provided. An array of arbitrary antenna elements and a reference receiver is provided. A location for a target source of signals is provided or assumed. Cross ambiguity functions are computed between the signal received by the reference receiver and the signal received by each antenna element. The cross ambiguity functions are analyzed to determine the phase and amplitude response of the antenna array to signals originating from the location of the target source of signals.

Abstract: A radar device includes an antenna, from which a detection signal is transmitted while the antenna being rotated and by which a reflective wave of the transmitted detection signal is received to detect echo data, wherein image data is generated based on the detected echo data, a continuity detecting module for detecting a planar continuity of the currently detected echo data with respect to a pixel concerned in the image data, a behavior data generating module for generating behavior data indicative of a behavior of the echo data for a predetermined number of scans of the past in the pixel concerned based on behavior determination data, and an echo kind determining module for determining a kind of the echo data of the pixel concerned based on the planar continuity and the behavior data.

Abstract: The general field of the invention is that of viewing systems of the synthetic vision type SVS, for a first aircraft, the said system comprising at least one cartographic database of a terrain, position sensors, for the said aircraft, an air traffic detection system calculating the position and the danger rating of at least one second aircraft exhibiting a risk of collision with the said first aircraft on the basis of data originating from sensors or systems such as TCAS or ADS-B, an electronic computer, a man-machine interface means and a display screen, the computer comprising means for processing the various items of information originating from the database, sensors and interface means, the said processing means arranged so as to provide the display screen with a synthetic image of the terrain comprising a representation of the said second aircraft.

Abstract: A weather radar system or method can be utilized to determine a location of a weather hazard for an aircraft. The weather radar system can utilize processing electronics coupled to an antenna. The processing electronics can determine presence of the hazard in response to data related to returns received by the weather radar antenna and data from a lightning sensor. The system can include a display for showing the hazard and its location.

Abstract: A depth-based image enhancement system is disclosed. A depth estimation unit generates three-dimensional (3D) depth information from a two-dimensional (2D) image. Subsequently, an image enhancement unit enhances the 2D image according to the 3D depth information.

Abstract: The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter's coverage relative to the position of the EA aircraft and to the position of any number of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour, a Jam Assessment Strobe (JAS) and text for display on a number of flexibly configurable display formats posted on display units. The JAR and JAS graphics and text will aid the EA aircrew in rapidly assessing the effectiveness of a given jamming approach.

Abstract: The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter's coverage relative to the position of the EA aircraft and to the position of any number of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour, a Jam Assessment Strobe (JAS) and text for display on a number of flexibly configurable display formats posted on display units. The JAR and JAS graphics and text will aid the EA aircrew in rapidly assessing the effectiveness of a given jamming approach.

Abstract: A radar device includes an antenna, from which a detection signal is transmitted while the antenna being rotated and by which a reflective wave of the transmitted detection signal is received to detect echo data, wherein image data is generated based on the detected echo data, a continuity detecting module for detecting a planer continuity of the currently detected echo data with respect to a pixel concerned in the image data, a behavior data generating module for generating behavior data indicative of a behavior of the echo data for a predetermined number of scans of the past in the pixel concerned based on behavior determination data, and an echo kind determining module for determining a kind of the echo data of the pixel concerned based on the planer continuity and the behavior data.

Abstract: The method generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the method is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter's coverage relative to the position of the EA aircraft and to the position of any number of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour, a Jam Assessment Strobe (JAS) and text for display on a number of flexibly configurable display formats posted on display units. The JAR and JAS graphics and text will aid the EA aircrew in rapidly assessing the effectiveness of a given jamming approach.

Abstract: A 3D rendered image of a radar-scanned terrain surface is provided from a radar return signal from the surface, wherein the return signal includes data indicative of azimuth, elevation, and range of a radar-illuminated area of the surface. The data are processed for transformation into X, Y, and Z coordinates. The X and Y coordinates corresponding to each illuminated area are triangulated so as to create a mesh of triangles representing the terrain surface, each of the triangles in the mesh being defined by a vertex triplet. 3D imaging information (grey scale shading and/or coloring information) is added to each triangle in the mesh, based on the amplitude of the radar return signal from the coordinates represented by each vertex in the triplet and the value of the Z coordinate at each vertex, so as to form the 3D rendered image.

Abstract: A system comprising a moving radar, a processing device, and a phase difference determination device is used to monitor a target. The moving radar has first and second phase centers that transmit and receive signals normal to a direction of movement of the radar. The processing device receives first and second ones of the received signals from the first and second phase centers, respectively, and performs a target motion compensation and target acceleration correction for each of the first and second received signals to produce first and second images. The phase difference determination device determines a phase difference image from a comparison of the first and second images.

Abstract: A weather radar system has bright band detection and compensation. The weather radar system determines that high reflectivity in weather is a bright band and reduces an encoded return level from the bright band to compensate for it on a display. The weather radar system detects the presence of the bright band using an inference system that uses outside air temperature, aircraft altitude, and an assumed lapse rate to estimate the bright band location relative to the aircraft and uses antenna elevation to estimate bright band range to reduce the encoded radar return level on the display. The weather radar system may also detect the presence of the bright band using a detection system that uses radar estimates from normal reflectivity scan operation of the system. The weather radar system may also use an active detection process separate from a normal radar sampling process to detect the bright band.

Abstract: A weather radar system or method can be utilized to determine a location of a weather hazard for an aircraft. The weather radar system can utilize processing electronics coupled to an antenna. The processing electronics can determine presence of the hazard in response to data related to returns received by the weather radar antenna and data from a lightning sensor. The system can include a display for showing the hazard and its location.

Abstract: The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter's coverage relative to the position of the EA aircraft and to the position of any number of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour, a Jam Assessment Strobe (JAS) and text for display on a number of flexibly configurable display formats posted on display units. The JAR and JAS graphics and text will aid the EA aircrew in rapidly assessing the effectiveness of a given jamming approach.

Abstract: The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter's coverage relative to the position of the EA aircraft and to the position of any number of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour, a Jam Assessment Strobe (JAS) and text for display on a number of flexibly configurable display formats posted on display units. The JAR and JAS graphics and text will aid the EA aircrew in rapidly assessing the effectiveness of a given jamming approach.

Abstract: Traffic collision and avoidance systems and methods for a host aircraft. The system receives traffic information from one or more target aircraft, determines threat levels of target aircraft associated with the received traffic information, generates one or more objects based on the determined threat levels and a pre-defined threat level, and displays the generated one or more objects that are associated with threat levels within the pre-defined threat level. A first indicator that indicates lateral position relative to the host aircraft and a second indicator that indicates vertical direction of travel of the associated target aircraft are also displayed.

Abstract: Weather radar reflectivity data is compressed by converting radar data to image pixels. Next, contours are traced from select groupings of the pixels. Control points are derived from the contours. The control points represent a compressed version of the radar data and may be used to recreate and fill the contours with predefined colors or effects for purposes of visually depicting weather phenomena.

Abstract: A 3D rendered image of a radar-scanned terrain surface is provided from a radar return signal from the surface, wherein the return signal includes data indicative of azimuth, elevation, and range of a radar-illuminated area of the surface. The data are processed for transformation into X, Y, and Z coordinates. The X and Y coordinates corresponding to each illuminated area are triangulated so as to create a mesh of triangles representing the terrain surface, each of the triangles in the mesh being defined by a vertex triplet. 3D imaging information (grey scale shading and/or coloring information) is added to each triangle in the mesh, based on the amplitude of the radar return signal from the coordinates represented by each vertex in the triplet and the value of the Z coordinate at each vertex, so as to form the 3D rendered image.

Abstract: The invention generally relates to the field of computer software particularly to an improved method of providing aircrew decision aids for use in determining the optimum placement of an Electronic Attack (EA) aircraft. The core of the invention is a software program that will dynamically provide the EA flight crew situational awareness regarding a threat emitter's coverage relative to the position of the EA aircraft and to the position of protected entities (PE). The software program generates information to provide visual cues representing a Jam Acceptability Region (JAR) contour and a Jam Assessment Strobe (JAS) for display via designated aircraft cockpit processors and devices. The JAR and JAS will aid the EA aircrew in assessing the effectiveness of a given jamming approach.

Abstract: A computer program which plots radar video data generated by a seeker on a missile. The program allows a user to plot multiple scans of radar video data on a chart, which is obtained from a Data Worksheet. The chart displays one or more sets of radar video data scans and a detection gate plot for each radar video data scan. The program includes Zoom In, Zoom Out, Pan Left and Pan Right functions which allow the user to view and manipulate views of the data displayed by the chart.

Abstract: Traffic collision and avoidance systems and methods for a host aircraft. The system receives traffic information from one or more target aircraft, determines threat levels of target aircraft associated with the received traffic information, generates one or more objects based on the determined threat levels and a pre-defined threat level, and displays the generated one or more objects that are associated with threat levels within the pre-defined threat level. A first indicator that indicates lateral position relative to the host aircraft and a second indicator that indicates vertical direction of travel of the associated target aircraft are also displayed.

Abstract: A weather radar system or method can be utilized to determine potential weather hazard for an aircraft in a terminal area. The weather radar system can utilize processing electronics coupled to an antenna. The processing electronics can determine presence of the potential in response to data related to returns received by the weather radar antenna. The data can include a mean velocity parameter or a spectral width parameter or reflectivity.

Abstract: Methods and apparatus are provided for operating a radar system to provide a thunderstorm image to a pilot. The method comprises using one or more radar scans depending upon the aircraft altitude, a single upward tilted scan at or below a datum level of about 15,000±3000 feet wherein a clutter free storm image may be obtained and two scans above the datum level; a first upward tilting scan to determine, clutter free, a storm head perimeter and a second lower tilting scan for the storm body with ground clutter. The perimeter is used to discard return echoes from the second scan that lie outside the perimeter or an expansion thereof and retain those lying on or within the perimeter. The result is presented to the pilot. Optionally, the thunderstorm image is graded from center to edge so as to indicate weaker echo intensity near the edge.

Abstract: A scan conversion is provided which allows the scan converter to work with data in its most convenient format in a radar memory. A displayable image is mirrored to a graphics memory simultaneously with the write portion of the radar memory of the scan conversion process. On every write to the radar memory, radar data is simultaneously converted to associated colors by indexing a color look-up table and writing the indexed color to the graphics memory. A simulated phosphor decay for the display is provided by decreasing the intensity of each pixel in the radar memory once each antenna scan and similarly decreasing the intensity of data in corresponding locations in the graphics memory to simulate the decay of a phosphor coated screen in a CRT display. The signals in the graphics memory are coupled to a display at a rate that simulates a display on a phosphor coated screen.

Abstract: A subject may be interrogated with electromagnetic radiation for producing image data representative of an image of the subject. First and second image data, produced based on reflectivity in first and second frequency ranges, may be related. In some examples, image data for one picture element may be produced based at least in part on reflectivity of the radiation at a depth selected based at least in part on a depth of another picture element. In some examples, plural images may be produced based on reflectivity at different depths. In some examples, a value of reflectivity may be determined for an intermediate depth between two adjacent depths of image data based at least in part on reflectivity of the radiation for a plurality of spaced-apart depths.

Abstract: An aircraft weather radar system is disclosed. The system comprises a radar antenna, aircraft sensors, and a database. The system also comprises a processing device receiving information from the radar antenna and from the aircraft sensors and able to retrieve information from the database. Further, the system comprises a cockpit display coupled to the processing device. The processing device is programmed to determine storm system hazards and to display the storm system hazards on the display using an iconal representation or textual representation.

Abstract: Embodiments of the invention provide a method and apparatus for indicating aircraft height relative to an obstruction in a terrain awareness warning system. The method includes receiving data indicative of geographic features of an obstruction, lateral distance of the geographic feature from an aircraft, height and flight path of the aircraft, calculating a projected height of the aircraft at the location of the obstruction using the data, generating a result signal, and displaying a colored indication on a display screen based on the result signal. The apparatus includes inputs for signals from instruments measuring height, flight path, and location of an aircraft, as well as an input for an instrument providing information about geographic features of terrain surrounding the aircraft. The apparatus includes a means for employing the signals to calculate an effective height of the aircraft relative to the terrain, and a screen display for graphically displaying the results of the calculation.

Abstract: An imaging millimeter wave radar system. The system includes a millimeter wave transmitter transmitting a frequency scanned millimeter beam that is narrow in the scanned direction and wide in a direction perpendicular to the scanned direction. The system includes a receive antenna and a Rotman type lens for forming a one-dimensional image in the perpendicular direction of targets in the antennas field of view based on millimeter wave radiation reflected from the targets. A computer creates a two dimensional image based on the scanning direction of the transmit beam of the transmit antenna and the one dimensional image from the receive antenna. Distance to the target is determined based on difference in frequency of the transmit signal and the receive signal. Thus, a three dimensional view of the systems field of view is determined by the system. This view can be displayed on a monitor using color to represent target distance.

Abstract: Embodiments of the invention provide a method and apparatus for indicating aircraft height relative to an obstruction in a terrain awareness warning system. The method includes receiving data indicative of geographic features of an obstruction, lateral distance of the geographic feature from an aircraft, height and flight path of the aircraft, calculating a projected height of the aircraft at the location of the obstruction using the data, generating a result signal, and displaying a colored indication on a display screen based on the result signal. The apparatus includes inputs for signals from instruments measuring height, flight path, and location of an aircraft, as well as an input for an instrument providing information about geographic features of terrain surrounding the aircraft. The apparatus includes a means for employing the signals to calculate an effective height of the aircraft relative to the terrain, and a screen display for graphically displaying the results of the calculation.

Abstract: A weather radar display system is disclosed. The weather radar display system comprises a weather radar antenna, processing electronics, coupled to the weather radar antenna, enhancing weather radar returns based on a reflectivity model which differentiates lower level activity from higher level activity when the weather activity is detected from weather systems at long range and the reflectivity using short range thresholds would display only higher level activity. A weather radar display displays multiple colors representative of the different levels of weather activity based on the enhanced returns.

Abstract: A system for allowing pilots to quickly determine weather hazard-free flight paths and weather hazards that exist along the aircraft flight plan. The system includes a memory, a processor, and a display device. The memory stores weather radar return information in a three-dimensional buffer. The processor is coupled to the memory. The processor receives a display distance value signal, retrieves weather radar return information stored in a plane of voxels in the three-dimensional buffer based on the selected display distance value and aircraft position information, and generates an image based on the retrieved weather radar return information. The display device is coupled to the processor for displaying the generated image.

Abstract: A surveillance and collision avoidance system provides a presentation of situational awareness information for display that includes a compound symbol for each target spaced at a distance and bearing relative to a host symbol. The target compound symbol includes indicia of (a) whether the target is airborne or on the ground; (b) whether the target is a civil aircraft, a military aircraft identified as a formation member with the host aircraft, or a military aircraft not identified as a formation member with the host aircraft; (c) whether a ground track for the target is unknown, known by passive surveillance, or known by active surveillance; (d) for civil aircraft, whether the target is the subject of no advisory, a traffic advisory, or a resolution advisory; and (e) for a military aircraft, whether the target is the subject of no encroachment advisory, an unintended encroachment advisory, or an intended encroachment advisory. Subsystems selectively use an active or a passive mode of surveillance.

Abstract: A method for determining a location of an emitter in a monitored area includes the step of providing an array representative of the monitored area, the array including a plurality of elements. Next, at least one first curve and at least one second curve is provided in the array. The first and second curves are representative of possible locations of the emitter in the monitored area. Then, possible emitter locations are identified at intersections of the first and second curves. The intersections are identified by determining locations in the array where an element having an assigned attribute corresponding to a first curve has a predetermined number of adjacent elements having an assigned attribute corresponding to a second curve.

Abstract: A method for determining a location of an emitter in a monitored area includes the step of providing an array representative of the monitored area, the array including a plurality of elements. Next, at least one first curve and at least one second curve is provided in the array. The first and second curves are representative of possible locations of the emitter in the monitored area. Then, possible emitter locations are identified at intersections of the first and second curves. The intersections are identified by determining locations in the array where an element having an assigned attribute corresponding to a first curve has a predetermined number of adjacent elements having an assigned attribute corresponding to a second curve.

Abstract: Embodiments of the invention provide a method and apparatus for indicating aircraft height relative to an obstruction in a terrain awareness warning system. The method includes receiving data indicative of geographic features of an obstruction, lateral distance of the geographic feature from an aircraft, height and flight path of the aircraft, calculating a projected height of the aircraft at the location of the obstruction using the data, generating a result signal, and displaying a colored indication on a display screen based on the result signal. The apparatus includes inputs for signals from instruments measuring height, flight path, and location of an aircraft, as well as an input for an instrument providing information about geographic features of terrain surrounding the aircraft. The apparatus includes a means for employing the signals to calculate an effective height of the aircraft relative to the terrain, and a screen display for graphically displaying the results of the calculation.

Abstract: A radar display system (10) according to the present invention generates textured radar display data by utilizing a direct memory access receiver (12) to receive radially scanned radar data, to convert the radially scanned radar data into range bin data sets, and to store the range bin data sets. A graphics renderer (18) stores the set of range bin data sets in a texture memory (20) as a plurality of rectangular textures, and bit maps the rectangular textures to a series of display triangles in a frame buffer (22). The graphics renderer (18) colors the display triangles in accordance with the rectangular textures by performing a bi-linear interpolation of the color and warps the display triangles in accordance with the size of a display (24).

Abstract: A weather radar display system displays a beam indicator indicative of a radar beam. The beam indicator represents width of the radar beam as a function of range (distance from the radar beam source). The beam indicator allows a pilot to easily discern accuracy of detected weather conditions based on the beam width.

Abstract: The relative altitude of the center of a radar beam in relation to the aircraft's altitude at a plurality of distance ranges from the radar source is computed. A plurality of range rings representing the distance ranges are displayed. The computed relative altitude is displayed adjacent to each range ring displayed.

Abstract: A surveillance and collision avoidance system provides a presentation of situational awareness information for display that includes a compound symbol for each target spaced at a distance and bearing relative to a host symbol. The target compound symbol includes indicia of (a) whether the target is airborne or on the ground; (b) whether the target is a civil aircraft, a military aircraft identified as a formation member with the host aircraft, or a military aircraft not identified as a formation member with the host aircraft; (c) whether a ground track for the target is unknown, known by passive surveillance, or known by active surveillance; (d) for civil aircraft, whether the target is the subject of no advisory, a traffic advisory, or a resolution advisory; and (e) for a military aircraft, whether the target is the subject of no encroachment advisory, an unintended encroachment advisory, or an intended encroachment advisory. Subsystems selectively use an active or a passive mode of surveillance.

Abstract: Embodiments of the invention provide a method and apparatus for indicating aircraft height relative to an obstruction in a terrain awareness warning system. The method includes receiving data indicative of geographic features of an obstruction, lateral distance of the geographic feature from an aircraft, height and flight path of the aircraft, calculating a projected height of the aircraft at the location of the obstruction using the data, generating a result signal, and displaying a colored indication on a display screen based on the result signal. The apparatus includes inputs for signals from instruments measuring height, flight path, and location of an aircraft, as well as an input for an instrument providing information about geographic features of terrain surrounding the aircraft. The apparatus includes a means for employing the signals to calculate an effective height of the aircraft relative to the terrain, and a screen display for graphically displaying the results of the calculation.