247 results about "Terrain elevation" patented technology

A method and system for providing a perspective view image created by fusing a plurality of sensor data for supply to a platform operator with a desired viewing perspective within an area of operation is disclosed. A plurality of sensors provide substantially real-time data of an area of operation, a processor combines the substantially real-time data of the area of operation with digital terrain elevation data of the area of operation and positional data of a platform operator to create a digital cartographic map database having substantially real-real time sensor data, a memory for storing the digital cartographic map database, a perspective view data unit inputs data regarding a desired viewing perspective of the operator within the area of operation with respect to the digital cartographic map database to provide a perspective view image of the area of operation, and a display for displaying the perspective view image to the operator.

A method of registering reconnaissance image data with map data is disclosed, comprising recording image data at a plurality of positions, together with the role, pitch and height above mean sea level data from an airborne navigation system and imaging system, and recording altitude of a reconnaissance craft from an altimeter; obtaining a difference between said recorded altitude data, and an altitude calculated from said navigation system data and a map data; selecting a difference data having a lowest standard deviation, and at a position of said selected difference data generating a three dimensional surface data using a bi-quadratic equation; generating a bi-quadratic surface of each of a plurality of positions for which data is recorded; generating a difference data between said bi-quadratic surface data, and height data obtained from said map, and minimising an error between bi-quadratic surface data and said height data by translating said position data relative to said map data, until minimum error is achieved; registering said image data with said map data after applying a said translation of said image data.

An altitude measuring system is described that includes a radar altimeter configured to measure altitude and a digital terrain map database. The database includes data relating to terrain elevation and at least one data parameter relating to an accuracy of the terrain elevation data and the altitude measured by the radar altimeter. The system is configured to weigh an altitude derived from the terrain elevation data and the radar altimeter measurements according to the at least one data parameter.

A display control device, having a processor structured for receiving terrain elevation information and samples of current position and altitude above ground data; and one or more algorithms resident on the processor for generating, as a function of the current position and altitude above ground data, one or more display control signals for causing a display device to display, in a monochromatic scale graduated as a function of terrain elevation relative to mean sea level, a strategic portion of the terrain elevation information extending between a minimum elevation of the strategic portion of the terrain elevation information and a pre-selected strategic altitude threshold less than the altitude above ground data.

The invention discloses a method for constructing a three-dimensional terrain vector model based on multi-beam sonar submarine measurement data, and relates to a method for constructing the three-dimensional vector terrain model with measurement data of multi-beam sonar, which solves the defect that a multi-beam ranging sensor can only provide discrete terrain elevation and can only query terrainparameters at a measurement point. The method is used for non-structural submarine terrain modeling and vector data retrieval. The method comprises the following steps of: acquiring a horizontal coordinate of a sampling point of the terrain of a submarine area and corresponding elevation data; defining a data structure of a terrain triangular net model according to characteristics of multi-beam sonar terrain measurement data; and finally, establishing a Delaunay triangular net vector model according to elevation data of each point of the multi-beam sonar terrain measurement and the data structure of a Delaunay triangular net.

A system for sensing aircraft and other objects uses bistatic radar with spread-spectrum signals transmitted from remotely located sources such as aircraft flying at very high altitudes or from a satellite constellation. A bistatic spread spectrum radar system using a satellite constellation can be integrated with a communications system and/or with a system using long baseline radar interferometry to validate the digital terrain elevation database. The reliability and safety of TCAS and ADS-B are improved by using the signals transmitted from a TCAS or ADS-B unit as a radar transmitter with a receiver used to receive reflections. Aircraft and other objects using spread spectrum radar are detected by using two separate receiving systems. Cross-Correlation between the outputs of the two receiving systems reveals whether a noise signal is produced by the receiving systems themselves or is coming from the outside.

The disclosed embodiments include an apparatus and method of using a laser to scan the ground or a target from an airborne or ground-based platform. In certain embodiments, the apparatus and method produces a 3-D elevation model of the terrain. In some embodiments, the apparatus includes a pulsed laser, a receiver to detect and amplify the pulse after being reflected by objects on the ground (or the ground itself), and electronics which measures the time of flight of the optical pulse from which the slant range to the target is calculated. Technical advantages of the disclosed embodiments include avoiding blind zones to ensure that no laser shots are wasted. In certain embodiments for airborne applications, the apparatus may also be configured to maintain a constant swath width or constant spot spacing independent of aircraft altitude or ground terrain elevation.

An aircraft weather radar system can be used with a terrain avoidance system. The aircraft weather radar system is coupled to an antenna. A processor receives radar returns received by the antenna. The processor determines terrain elevation estimates for use with the terrain avoidance system from the radar returns. The terrain elevation estimates are compared to stored terrain elevation data used with the terrain avoidance system to verify position or to check the integrity of the stored elevation data. The processor can be part of a terrain avoidance system, a weather radar system, a navigation system, or can be a standalone system.

A generalized framework is disclosed in which a wide variety of propagation models can be cast in a matrix-based format using arbitrary matrix coefficients (e.g., real numbers, integers, etc.). Casting propagation models in the matrix-based framework enables efficient computer implementation and calculation, ease of tuning, admissibility (i.e., the tuned parameters of a linear matrix model are guaranteed to be the global optimum), and aggregating multiple propagation models into a single matrix-based model. Matrix-based propagation models based on transmitter-receiver azimuth orientation, transmitter antenna height, terrain elevation, and clutter are also disclosed. The propagation models can be used in conjunction with automated data acquisition from information sources such as topographic maps, clutter maps, etc.

Three-dimensional imaging techniques are used for a visualization method and apparatus. In a preferred embodiment, terrain data is displayed as a series of pixels—areas of terrain elevation data. Individual pixels are analyzed to determine whether they are locally smooth or “warpable” relative to their surrounding neighbor pixels. Those pixels that are locally relatively “smooth,” i.e., those satisfying a given set of criteria, are joined with adjacent neighbor pixels by a process referred to herein as “warping” to create “smooth,” gap-free surfaces. A preferred embodiment includes drawing or generating lines between the centers of two pairs of adjacent pixels to determine a slopes m₁ and m₂ respectively. The slopes m₁ and m₂ are then analyzed using the following equations/determinations: |m₁∥≦m_max; |m₂∥≦m_max; and |m₁−m₂|≦Δmax; i.e., the slopes m₁ and m₂ must each be less than or equal to a predetermined threshold m_max and the difference between the slopes must be less than or equal to a predetermined difference Δmax.

The invention discloses a complex riverway terrain quick and fine generation method. By performing unified block division, classification and numbering on spatial relationships of complex terrain boundary points, scattered boundary points are fitted with a natural riverway course and a new riverway boundary is generated, so that the problem of disorder of a large amount of boundary points of a riverway is solved; through a finite riverway monitoring section terrain, based on a weight interpolation method, quick generation of a riverway terrain is realized; and the terrain is generated throughriverway interpolation, and accurate supplement of a riverway section is realized by utilizing a distance between a to-be-supplemented section and a known sampling elevation section of the riverway, and a gradient change. According to a characteristic that the scattered boundary points of the riverway and terrain elevation sampling data cannot meet riverway hydrodynamic calculation precision requirements, the modes of riverway boundary fitting, riverway terrain interpolation and riverway sampling elevation section supplement are adopted, the characteristics of the natural riverway course and the terrain change are fully considered, and the terrain interpolation errors are effectively reduced.

The invention discloses a high-fidelity digital modeling method of terrain elevation, the steps are as follows: the first step is to carry out push-broom data acquisition; the second step is to carry out grid segmentation of the acquired vector terrain feature data; the third step is to carry out similar DEM grid data organization of PLA, organization management is carried out to the PLA data after the grid segmentation treatment according to grid data structure; the fourth step is to generate a new digital elevation model file to carry out the seamless embedding of the vector feature data; a feature embedded digital elevation model data structure is composed of three sub-files which comprise a grid file, a feature identification file and a feature file; the grid file is a regular grid data structure; the feature identification file is used for spatial data index of a vector grid integrated organization, the structure thereof is consistent with the current national DEM data structure and only records the grids with the features; the feature file records terrain feature information which is contained in one grid unit, and the information comprises feature points and feature lines.

This method makes it possible to plot, from a terrain elevation database, a map of the distances of the points accessible to a moving object subject to constraints (inaccessible reliefs, unnegotiable obstacles, weather disturbances, path with an imposed vertical profile, etc.), the distances being measured only along paths that are practical for the moving object. It employs a chamfer distance transform applied to the image consisting of the projection on the horizontal plane of a 3D representation of the flying space of the moving object, which is likened to a mesh of elementary cubes associated with specific negotiation danger levels. It lists the typical paths without exceeding an acceptable danger threshold, going from a target point, the distance of which is to be estimated, to a source point, the origin of the distance measurements, and likens the distance of the target point to the length of the shortest practicable path or paths.

A position estimation system including a first arrangement for providing an image with a known target in a known reference frame. A second arrangement correlates the image with a stored image. The correlation is used to compute an error with respect to a position estimate. In a specific embodiment, the error is referenced with respect to first (x), second (y) and third (z) directions. A target location error is computed with respect to a stored image provided by a target image catalog. The target image catalog includes target geo-locations and digital terrain elevation data. In an illustrative application, the image data is provided by synthetic aperture radar and forward-looking infrared systems. An observation model and a measure noise matrix are Kalman filtered to ascertain a position error in navigation data generated by an integrated inertial navigation and Global Positioning system. In the illustrative application, geo-registered SAR/FLIR imagery is used to track targets and to determine a target location error (TLE). This TLE information is a set of error equations that describe the relationship between vehicle navigation information and target data. In accordance with the invention, this relationship is used to form an observation model for vehicle navigation with respect to target locations. Using Kalman filtering and the observation model, vehicle navigation errors can be bound and the navigation accuracy of the vehicle can be improved.

A radar acquires a formed SAR image of radar scatterers in an area around a central reference point (CRP). Target(s) are within the area illuminated by the radar. The area covers terrain having a plurality of elevations. The radar is on a moving platform, where the moving platform is moving along an actual path. The actual path is displaced from an ideal SAR image acquisition path. The radar has a computer that divides the digital returns descriptive of the formed SAR image into multiple blocks, such as a first strip and an adjacent strip. The first strip is conveniently chosen, likely to generally align with a part of the area, at a first elevation. An adjacent strip covers a second part of the area at a second elevation. The first strip is overlapping the adjacent strip over an overlap portion. The first and second elevation are extracted from a terrain elevation database (DTED). Horizontal displacement of returns (range deviation) is computed for each strip using the elevation information from the terrain elevation database. Taylor series coefficients are computed for the horizontal displacement due to terrain elevation using the ideal path, the actual path and central reference point. Actual flight path deviation is available at each pulse position while azimuth frequency is given in azimuth angle off mid angle point. Remapping between indices in two arrays is also computed. Phase error compensation and compensation in azimuth (spacial frequency) is computed using the Taylor series coefficients, a Fast Fourier Transform and an inverse Fast Fourier Transform for each strip. Phase error compensation is applied to the digital returns from each strip to obtain the SAR image. The SAR image is further improved by having the first strip corrected data and the second strip corrected data merged over the overlap portion to generate a relatively seamless SAR image.

The terrain referenced navigation system uses data from a global positioning system (GPS) to determine a vehicles position, velocity and height above ground. The system uses input data from an altimeter device, a digital terrain elevation data, and a GPS position, velocity and time data. The system applies a GPS error process model in addition to a TRN measurement model, to obtain a state vector which includes estimates of current errors in the GPS data. The PVT data input from a GPS receiver is used to determine a current vehicle position and height in geographic axis. Using specifically constructed Kalman filter states, a geographical position and height of the vehicle is reference to the digital terrain elevation data, and an estimated ground clearance at the vehicle position is determined. The ground clearance is differenced with a radar altimeter output, and the residual is processed by Kalman filter to determine a new state vector, including estimates of current errors in the GPS data. The output can be configured to be either referenced to navigation axis, or to the digital terrain database for use by other digital terrain system functions.

A method, apparatus, and computer usable program code for presenting terrain elevation information on a vehicle display. In one advantageous embodiment, a swath representing an area ahead of the vehicle is identified, wherein the swath has a length and a width. A two dimensional elevation view is presented on the vehicle display, wherein a vertical axis of the two dimensional elevation view represents a highest elevation along a width of a swath for a particular point along the length of the swath. The width of the swath is updated in response to vehicle movement to form an updated swath width. The two dimensional elevation view is updated using the updated swath width.

A method and apparatus for using a predetermined portion of terrain elevation maps in a database for aiding in computing a three-dimensional position of a wireless station. Instead of using the entire terrain model of the earth or an entire country, the database consists of an incomplete model, which includes only the most populous areas or specific regions. This reduces the size of the information in the database, which in turn reduces the amount of time to compute the positions of the wireless device.

A precision hoe opener assembly is provided with improved accuracy of seeding as well as improved control over the opener and packer wheel assemblies. The opener assembly includes a hydraulically-driven parallel linkage assembly, hoe opener, and a packer wheel. The design provides improved seeding accuracy, especially during changes in terrain elevation.

The present invention is a system for communicating the flood risk of a property to a user comprising a computer network, a first computerized device for displaying flood risk information in electronic communication with a computer network, a first database connected to said network, where said first database contains flood zone information arranged by geographic coordinates, a second database connected to said network, where said second database contains terrain elevation data arranged by geographic coordinates, a third database connected to said network, where said third database contains rainfall data arranged by geographic coordinates, a fourth database connected to said network, where said fourth database contains a record of prior flooding arranged by geographic coordinates, a fifth database connected to said network, where said fifth database contains a record of losses arranged by geographic coordinates, and a second computerized device connected to said network which calculates flood risk information for geographic location using an algorithm to process database information contained in said databases.