CA2297177A1 - Avionic system intended for use in aircrafts and involving use of an on-board radar equipment - Google Patents
Avionic system intended for use in aircrafts and involving use of an on-board radar equipment Download PDFInfo
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- CA2297177A1 CA2297177A1 CA002297177A CA2297177A CA2297177A1 CA 2297177 A1 CA2297177 A1 CA 2297177A1 CA 002297177 A CA002297177 A CA 002297177A CA 2297177 A CA2297177 A CA 2297177A CA 2297177 A1 CA2297177 A1 CA 2297177A1
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- radar
- avionic system
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/04—Display arrangements
- G01S7/06—Cathode-ray tube displays or other two dimensional or three-dimensional displays
- G01S7/22—Producing cursor lines and indicia by electronic means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
- G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
- G01S13/9021—SAR image post-processing techniques
- G01S13/9023—SAR image post-processing techniques combined with interferometric techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
- G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
- G01S13/904—SAR modes
- G01S13/9043—Forward-looking SAR
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/04—Display arrangements
- G01S7/06—Cathode-ray tube displays or other two dimensional or three-dimensional displays
- G01S7/20—Stereoscopic displays; Three-dimensional displays; Pseudo-three-dimensional displays
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/04—Display arrangements
- G01S7/06—Cathode-ray tube displays or other two dimensional or three-dimensional displays
- G01S7/24—Cathode-ray tube displays or other two dimensional or three-dimensional displays the display being orientated or displaced in accordance with movement of object carrying the transmitting and receiving apparatus, e.g. true-motion radar
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/91—Radar or analogous systems specially adapted for specific applications for traffic control
- G01S13/913—Radar or analogous systems specially adapted for specific applications for traffic control for landing purposes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
- G01S13/933—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of aircraft or spacecraft
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/95—Radar or analogous systems specially adapted for specific applications for meteorological use
- G01S13/953—Radar or analogous systems specially adapted for specific applications for meteorological use mounted on aircraft
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Abstract
The invention pertains to an on-board radar equipment as part of the avionic system in an aircraft, said equipment providing a two-dimensional representation of the radar data from an area located upstream relative to the flight direction. The inventive radar equipment is an upstream sighting radar which gives of the radar data a high resolution and map-consistent representation from above in accordance with its basic operating mode resting upon the SAR(synthetic aperture radar)-based processing principle or an equivalent principle. A digital image processor enables a purely geometrical conversion of the map-consistent representation from above provided by said radar equipement into a corresponding image with a centered perspective projection and with a quasi-pilot vision. The invention is used when aircrafts and helicopters fly under bad visibility conditions or with no visibility at all.
Description
. CA 02297177 2000-O1-21 Patent Attorney von Kirschbaum Attorney Cocker: DFO-9836 PCT
DESCRIPTION
AVIOVIC SYSTEM FOR AIRCRAFi,.EMPLOYING AN 0~-HOARD RADAR
DEVICE
FIELD OF SHE INVENTION
The invention relates to an avionic system for aircraft, empioyi.g an on-board radar device Lhat displays a two-dimensional, perspective image of the radar data obtained for a sector region that lies ahead in the flight direction, incl~~ding objects de~ected there, on a viewing device.
DFSCRIPTION OF THE RELATED ART
U.S. Patent No. 3,988,731 discloses a radar device that provides a two-dimensional, perspective representation of a ;0 sector regior. ly_ng ahead in the flight direction. In this case, the respective sector is scanned by means of a tightly-bundled fan beam that pivots in Lh~ horizontal plane. ;he reflected radar signal is represented on the viewing device, wish deflecting voy ages being generated in '~S the hcrizontal and vertical directions, similarly to the generation of television images.
So that remote landmarks and flying objects are not superimposed too closely during a low-altitude flight, and therefore cannot be resolved further, the position of the 20 aircraft carrying the radar is artificially raised to a higher position through a change in the deflecting voltages, so the remote landmarks and flying objects located close together lie further apart in elevation.
The pilot is therefore deceived by a higher flight altitude. An analog vertical.and horizontal deflection occurs on the monitor; a vantage point other than the actual vantage point is simulated through a charge in the de°leccion voltages_ Images are generated based on the real antenna aperture of the mechanically-pivoted antenna with a tight fan bund'~ing in the azimuth plane. mhe dis=ance radar 1~ resolution is determined by the radar pulse length.
German Patent documents DE 40 07 611 and DE 40 07 612 di3close a forward-looking radar in which two-dimensional iTages are formed from land or water surfaces in a forward sector from a flying platform, such as ar. airplane. To this i5 end, in the known forward-looking radar, an antenna that is rigidly mounted to the platzorm is cons~ructed from either a plurality of irdividLal elements (DE 40 C7 611) disposed in a straight row next to one another, or from a plurality of individual elements (DE 40 07 612), preferably in the form 20 of horn antennas that are disposed in a straight line next .o each other, and in two superposed rows. With a predetermined aperture length 1 of each individual element, and a predetermined spacing of n individual elements, the antenna has an antenna length of L = n - I (DE 40 07 611) or 25 an antenna length of L = n ~ 1/2 (DE 40 07 612).
In the first nocument (DE 90 07 611), an individual element transmits incoherently, and the other individual elements subsequently receive simultaneously. In the second
DESCRIPTION
AVIOVIC SYSTEM FOR AIRCRAFi,.EMPLOYING AN 0~-HOARD RADAR
DEVICE
FIELD OF SHE INVENTION
The invention relates to an avionic system for aircraft, empioyi.g an on-board radar device Lhat displays a two-dimensional, perspective image of the radar data obtained for a sector region that lies ahead in the flight direction, incl~~ding objects de~ected there, on a viewing device.
DFSCRIPTION OF THE RELATED ART
U.S. Patent No. 3,988,731 discloses a radar device that provides a two-dimensional, perspective representation of a ;0 sector regior. ly_ng ahead in the flight direction. In this case, the respective sector is scanned by means of a tightly-bundled fan beam that pivots in Lh~ horizontal plane. ;he reflected radar signal is represented on the viewing device, wish deflecting voy ages being generated in '~S the hcrizontal and vertical directions, similarly to the generation of television images.
So that remote landmarks and flying objects are not superimposed too closely during a low-altitude flight, and therefore cannot be resolved further, the position of the 20 aircraft carrying the radar is artificially raised to a higher position through a change in the deflecting voltages, so the remote landmarks and flying objects located close together lie further apart in elevation.
The pilot is therefore deceived by a higher flight altitude. An analog vertical.and horizontal deflection occurs on the monitor; a vantage point other than the actual vantage point is simulated through a charge in the de°leccion voltages_ Images are generated based on the real antenna aperture of the mechanically-pivoted antenna with a tight fan bund'~ing in the azimuth plane. mhe dis=ance radar 1~ resolution is determined by the radar pulse length.
German Patent documents DE 40 07 611 and DE 40 07 612 di3close a forward-looking radar in which two-dimensional iTages are formed from land or water surfaces in a forward sector from a flying platform, such as ar. airplane. To this i5 end, in the known forward-looking radar, an antenna that is rigidly mounted to the platzorm is cons~ructed from either a plurality of irdividLal elements (DE 40 C7 611) disposed in a straight row next to one another, or from a plurality of individual elements (DE 40 07 612), preferably in the form 20 of horn antennas that are disposed in a straight line next .o each other, and in two superposed rows. With a predetermined aperture length 1 of each individual element, and a predetermined spacing of n individual elements, the antenna has an antenna length of L = n - I (DE 40 07 611) or 25 an antenna length of L = n ~ 1/2 (DE 40 07 612).
In the first nocument (DE 90 07 611), an individual element transmits incoherently, and the other individual elements subsequently receive simultaneously. In the second
- 2 -embodiment (DE 40 d7 612). the individual elements transmit and subsequently receive consecutively, specifically from the first to the last of the plurality of individual elements.
:o effect a digital coupling of the inaividual elements, each individual element is separately evaluated dyg~tally, and, in both cases, a digital processing is performed for each angular range through the correlation of a special, predetermined reference function.
The following advantages ara attained with a forward-looking radar of this type having a rigidly-mounted antenna and a subsequent, specially-designed processing method:
a~ a high pivoting speed of the antenna lobe, because the speed is attained electronically wi~h t:ne a;d of special data processing, not mechanically;
b) a higher precision and, consequently, a better quality of she images than with all devices available to this point;
c) no dependence on the platform speed: arid d) considerably lower maintenance costs.
A forward-looking radar system ef this type can also be used ir. connection with helicopters, for example for search-and-rescue or environmental missions, because no forward speed is necessary for the use of this forward-looking radar system, and the inherent movement of a stationary helicopter located at n predetermined site is insignificant_ In conclusion, it is noted here that U.S. 5.053,70 discloses a method of imaging a topographical land model
:o effect a digital coupling of the inaividual elements, each individual element is separately evaluated dyg~tally, and, in both cases, a digital processing is performed for each angular range through the correlation of a special, predetermined reference function.
The following advantages ara attained with a forward-looking radar of this type having a rigidly-mounted antenna and a subsequent, specially-designed processing method:
a~ a high pivoting speed of the antenna lobe, because the speed is attained electronically wi~h t:ne a;d of special data processing, not mechanically;
b) a higher precision and, consequently, a better quality of she images than with all devices available to this point;
c) no dependence on the platform speed: arid d) considerably lower maintenance costs.
A forward-looking radar system ef this type can also be used ir. connection with helicopters, for example for search-and-rescue or environmental missions, because no forward speed is necessary for the use of this forward-looking radar system, and the inherent movement of a stationary helicopter located at n predetermined site is insignificant_ In conclusion, it is noted here that U.S. 5.053,70 discloses a method of imaging a topographical land model
- 3 -chat is represented in a three-dimensional space, the model being created through the simultaneous combination of an image generated in accordance wits the SAR (Synthetic Aperture Radar) principle with ground-elevation information in an aircraft. The ground-elevation information is obtained either from the aircraf=, for example by means of a radar height finder, or thro~~gh ground measurements. A
perspective representation of a terrain sector ahead of the aircraft is not provided in the pilot's view.
T_t is the object of the present invention zo provide an avionic system that is suited for flat-wing as well as rotary-wing aircraft, and is initiated by the pilot to fly precisely to a desired target region, even under unfavorable 1.5 visibility conditions or with zero visibility, while meeting extremely-high precision requirements, and to identify even relatively-small obstacles, land safely and star up without problems, with zero visibility.
According to the invention, which relates to an avionic ?0 system of the type mentioned at the outset, this object is accomplished in that the radar device is a forward-looking radar which, corresponding to its basic operating mode, produces a high-resolution, map-consistent, overhead image of received radar data, using the SAR (Synthetic Aperture ~5 Radar) principle, or a processing principle similar to SAR.
Also according to the invention, a digital image-processing system is provided, in which the map-consistent,
perspective representation of a terrain sector ahead of the aircraft is not provided in the pilot's view.
T_t is the object of the present invention zo provide an avionic system that is suited for flat-wing as well as rotary-wing aircraft, and is initiated by the pilot to fly precisely to a desired target region, even under unfavorable 1.5 visibility conditions or with zero visibility, while meeting extremely-high precision requirements, and to identify even relatively-small obstacles, land safely and star up without problems, with zero visibility.
According to the invention, which relates to an avionic ?0 system of the type mentioned at the outset, this object is accomplished in that the radar device is a forward-looking radar which, corresponding to its basic operating mode, produces a high-resolution, map-consistent, overhead image of received radar data, using the SAR (Synthetic Aperture ~5 Radar) principle, or a processing principle similar to SAR.
Also according to the invention, a digital image-processing system is provided, in which the map-consistent,
- 4 -overhead view produced by the radar device is converted purely geometrically into a corresponding image with a centered-perspective projection in a quasi-pilot view. which .s then displayed on the viewing device.
The radar resolution is no longer effected by the real aperture of an antenna, but through the correlation of the corresponding reference functions, as described in the above-cited pate n documents CE 40 C7 611 azd DE 40 07 612.
Here, the overhead image is generated 'first.
1p The conversion =nto a perspective representation corresponding to a pilot view involves a purely computerized image processing, and can be performed exclusively digitally. This changes the image correspondingly, so the perspective is d~'ferent. Suitable image-processing 1~ algorithms can easily be created as software.
The image prodLCed on the viewina device with the application of the _r.vention is h~~ghly qual-tative, because the SAR method can produce an image with an extremely-high resolution. For the pilot to attain a precise, and 2d therefore reliab~e, flight orientation under poor visibility conditions, in accordance with the invention, it is especially advantageous to replace a conventional radar system operating with a real antenna aperture with the SAR
processing principle, which is otherwise on=y applied for 25 terrain observations in the aforementioned application.
Because of these features of the avionic system of the invention, the use and application of the forward-looking radar system has a wide application spectrum thet
The radar resolution is no longer effected by the real aperture of an antenna, but through the correlation of the corresponding reference functions, as described in the above-cited pate n documents CE 40 C7 611 azd DE 40 07 612.
Here, the overhead image is generated 'first.
1p The conversion =nto a perspective representation corresponding to a pilot view involves a purely computerized image processing, and can be performed exclusively digitally. This changes the image correspondingly, so the perspective is d~'ferent. Suitable image-processing 1~ algorithms can easily be created as software.
The image prodLCed on the viewina device with the application of the _r.vention is h~~ghly qual-tative, because the SAR method can produce an image with an extremely-high resolution. For the pilot to attain a precise, and 2d therefore reliab~e, flight orientation under poor visibility conditions, in accordance with the invention, it is especially advantageous to replace a conventional radar system operating with a real antenna aperture with the SAR
processing principle, which is otherwise on=y applied for 25 terrain observations in the aforementioned application.
Because of these features of the avionic system of the invention, the use and application of the forward-looking radar system has a wide application spectrum thet
- 5 -encompasses, for example, military reconnaissance and combat helicopters, rescue and off-shore helicopters and transport and civilian aircraft. The image quality attained with the system of the invention cannot,be attained with any other system at this time.
Tne avionic system of the invention thus provides an all-weather sensor that can even be used under poor visibility conditions, or zero-visibility conditions, as well as at night. The centered-perspective projection in a quasi-pilot view according to the invention creates a quasi-opLical image with a continuous image representation, for example or. a high-resolution color monitor, through a high image-repetition rate.
The dependent claims describe advc.ntageous modifications.
Eleva~cion information pertaining to the terrain of the scanned sector region is advantageously incorporated, in a partial 3-D representation, into the represented image. In an especially advantageous embodiment, the elevation information can be generated directly according to the interferometric principle.
According to a further advantageous modification of the invention, elevation information pertaining to the elevation above ground of natural and/or man-made obstacles are incorporated, in a paztial 3-D representation, into the image with a centered-perspective projection with a quasi-pilot view. Furthermore, color-coding can be implemented in the two representation modes (overhead view and pilot view).
Tne avionic system of the invention thus provides an all-weather sensor that can even be used under poor visibility conditions, or zero-visibility conditions, as well as at night. The centered-perspective projection in a quasi-pilot view according to the invention creates a quasi-opLical image with a continuous image representation, for example or. a high-resolution color monitor, through a high image-repetition rate.
The dependent claims describe advc.ntageous modifications.
Eleva~cion information pertaining to the terrain of the scanned sector region is advantageously incorporated, in a partial 3-D representation, into the represented image. In an especially advantageous embodiment, the elevation information can be generated directly according to the interferometric principle.
According to a further advantageous modification of the invention, elevation information pertaining to the elevation above ground of natural and/or man-made obstacles are incorporated, in a paztial 3-D representation, into the image with a centered-perspective projection with a quasi-pilot view. Furthermore, color-coding can be implemented in the two representation modes (overhead view and pilot view).
- 6 -In an advantageous modification of the avionic system according to the invention, the system switches between a first display mode, in which the sector is imaged in a map-consistent, ovarhead view, and.a second display mode, in which the sector is imaged in the centered-perspective projection in a quasi-pilot mew en the viewing device.
In ari analogous manner, a radar device in the form of a forward-looking radar can also be used in nautica'_ navigation in that the radar data obtained for a forward ..0 sector region in the direction of travel, including objects detected there, are imaged in a two-dimensional, perspective representation on a viewing device. Here, in an image-processing device, a high-resolution, overhead image is converted purely geometrically into a corresponding image having a centered-perspective projection in a quasi-helmsman view, and is displayed on the viewing device_ Elevation information about the scanned, forward sector region can also be incorporated, in a partial 3-D represen~ation, into the image with a centered-perspective projection. in a quasi-helmsman view; elevation information pertaining to the elevation of natural and/or man-made obstacles can also be incorporated in a 3-D representation.
Moreover, according to a further advantageous embodiment of the invention, obstacles that may be present z5 during landing approaches, and project beyond a pradetermined elevation above ground, can be color-coded botr in the map-consistent, overhead image and the quasi-pilot view. Likewise, targets, particularly moving targets, selected during reconnaissance flights can be marked -preferably with color - in both the overhead image and the quasi-pilot view.
An especially practical and advantageous modification of the avionic system according to tre invention lies in the insertion of an artificial horizon in~o the image.
In accordance with an advantageous embodimen~ of the invention, the cen~ered perspective representation in a quasi-pilot view, with the inserted artificial horizon, is also maintained in curved flight patterns. for exaT,p~e, according to a modification of the invention, it is possible to switch between map-consistent, overhead imaging and a centered perspective representation in a quasi-pilot view, with a respective inserted, artificial horizon, on a highly-1.5 sensitive color monitor, even during curved flight patterns.
Likewise, it is possible to switch between different range regions in both the map-consistent, overhead imaging and the centered perspective representation in a quasi-pilot view with the respective inserted, azti=icial :~.ori2on, which :?0 assures an extended-sight mode.
In accordance with a further advantageous embodiment of Che invention, it is also possible to switch the forward-looking radar system between different frequency ranges, for example from the L band (1.3 GHz) across the X band (9.6 .25 GHZ) and up to the Ka band, which is at about 35 GHz, as a function of the respective field of application. :n the switch to the Ka bend, the forwazd-looking radar system can be used to recognize high-voltage lines, for example, or wire fences used for bordering areas.
In accordance with an advantageous embodiment of the invention, she centered perspective representation in a quasi-pilot view, with or with4ut an inserted artificial S horizon. can be automatically adapted to the flight altitude arid flight speed.
As further advantageous modifications of the invention, additional data or information Can be inserted into the centered perspective representation in a aaasi-pilot view, :,0 such as distances to marked targets. the altitude of marked targets or a marking of moving targets, resulting in an MTI
(Moving Target Indication) mode. Moving targets can also be marked.
Within the =ramework of the invention, it is also 15 possible to combine the centered perspective representation in a quasi-pilot view with further operating modes, such as weather radar, surveillance radar or the 1'_ke.
Because of the high resolution capability attainable with the use of the avionic system of the invention, a 20 device that warns of obstacles can be actuated or initiated, for example, with the aid of received and purposeiu~ly selected data. It is also possible to produce a so-called head-up display representation.
In accordance with a further advantageous embodiment of 25 the invention, in addition to the image of the earth's surface. information pertaining to the elevation above around of natural and/or artificial obstacles can be inclLded in the quasi-pilot view.
The high-resolution graphic representation of the flight sector lying ahead in the flight direction that can be attained with the use of the forward-looking radar system permits an application for flights within civil and military scopes; thus, for example, autonomous landing approaches, purposeful, precise load jettison'_na and the like can be executed Yeliably.
BRIEF DESCRIPT:ON -OF THE DRAWINGS
The invention is described in derail below by way of :LO various embodiments, with reference to the attached draw_r.gs, which show in:
Ficr. _ a schematic representat~_on of an antenna constructed from a plurality of adjacent individual radiators, for use in forward-looking i5 radar;
Fig. 2 a schematic representation of an illuminating geometry, as results from an aircraft flying in a predetermined flight direction:
Fig. 3 a plan view, in a map-consistent representation, 2C of a portion of a runway and its immediate vicinity from a flight altitude of 1000 m:
Fig. 4 a centered-perspective representation in a quasi-pilot view of the same portion of the runway and its immediate vicinity, corresponding to the 25 representation of fig. 3;
Fig. S again, a plan view, in a map-consistent representation; of n portion of a runway. but from - l0 -a flight altitude of 300 m;
Fig. 6 a centered-perspective representation in a quasi-pilot view, corresponding to the map-consistent representation of Fig_. 3; and Figs. 7 & 8 in :nap-consistent representations, respectively a plan view of a tree formation from a flight altitude o_' 100 m and special markings for regions having a certain elevation above gro::.~.d ( Fig . 8 ) .
;) ~MHODIMENTS O~' THE INVENTION
Eig. 1 scl~.ematically shows n individual radiators in the form of horn antennas 10 disposed in a straight-line, adjacent antenna arrangement 1. In an arrangement not shown in detail, the antenna arrangement 1 is rigidly mounted to :~ an aircraft - which is shown on a greatly-reduced scale -specifically transversely to its flight direction, which is indicated by an arrow, such that the primary radiation direction of the horn antennas 10 is orien~ed in the flight direction.
c0 According to DE 40 07 611, only one individual radiator, i.e., one horn antenna 10, transmits; however, all of the other individual elements, for example i:~ the form of the horn antennas 10, then receive. .n contrast, in D~ 40 07 612, the n _ndividual radiators are used consecutively a?5 from the first to the nth element to transmit, then to receive.
The rev data can be processed in a manner similar to a.
the known SAR principle, with a synthetic aperture in DE 90 07 611 being replaced by half the spacing or, in DC 40 07 612, by the spacing between the first and the nth individual radiators of the horn-antenna arrangement.
During the processing, the respect=ve signal is correlated according to amplitude and phase, as a function of the range, with a conjugated complex reference function, not disclosed in detail here. A decisive factor. however, is chat. at each individual element 10, the received signal has a phase that differs from the tra:.smitted pulse due to the di=ferent location between the transmitter and receiver.
This means thzt, in incoherent operation, the phase relationship be~ween the individual elements must be constant and known iDE 90 07 6i1>. Because coherent ~5 operation is employed in the transmitting and receiving branches in DE 40 07 612, the relative phase position of the signals received at different locatio-~s must be known in this operating mode.
Tf the spacing between the n individual radiators 10 is :20 ox, this spacing can be expressed by px = 1 = h/O in DE 40 07 611; or Ox = I/2 = x/20 in DE 40 07 612, where I is the aperture length of each individual radiator, is the wavelength and ~ is the illumination angle. The 25 illumination ang~e O is shown schematically in the illumination geometry in Fig. 2.
If the distance between a target point T and an individual radiator 10 of the respective antenna arrangement is represented by r, a. can be inferred from the schematic representation of Fig. 2, the distance r can be expressed by:
R~ + Ca-x)Z , with a representing zhe-distance between the central antenna axis O and a point targat T, x representing the distance between the central an~enna axis O and an individual radiator 10 and R representing the range-gate spacing, which can also be inferred in detail fzom the schematic representation of Fig. 2.
.LO Fig. 3 shows a map-consistent, o~rerhead view produced with a relatively-short antenna from a flight altitude of 1000 m in the X band. a portion of a runway can be identified approximately in the center of the figure.
Fig. 9 Shows the corresponding, centered-perspective .5 representation in a quasi-pilot view, which has been obtained through a corresponding conversion of the map-consistent representation in the overhead view of Fig. 3.
The upper region of Fig. 4 shows a portion of the runway, while the lower region shows the area located in front of 20 the runway, seen in the flight direction. In Fig. 9. an inserted artificial horizon, :or example in the form of a black bar, is shown along the upper longitudinal edge of the representation.
In Figs. 3 and 4, the illumination angle i5 60° in the 25 azimuth direction, and the depression angle ranges from 19°
to 60°. The resolution in the azimuth direction is 10 m in the close range and 35 m in the remote range, while the resolution in the elevation direction is 3 m.
Fig. 5 shows a portion of the same runway in a map-consistent, overhead view, in this case from a flight altitude o~ 300 m_ Eig. 6 shows the centered-perspective representation in a quasi-pilot view. An insertea arLi=yc~a,l. 11VL14V11, iwt example in the form of a black bar, is shown along the upper lo..~.gitudizal edge.
'LO Fig. 7 shows a map-consistent, overhead view of a tree and bush formation at an X-band frequency of 9.6 GKz and from a flight altitude of 100 m.
Fig. 8 shows the same cutout as in Fig. ~. In the practical embodiment, colored markings indicate regions that project at an elevation of, for example, more than 3 m above the surrounding =egion, i.e., 3 m above the ground-;n Figs. 7 and 8, as in Figs. 3 and 4, the illumination angle is 60° in the azimuth direction, and zhe depression angle ranges ~rom 14° to 60°. In Figs. 7 and 8, the surface area resolution is 0.6 mZ in the near range, and 1.1 mZ in the remote range.
In ari analogous manner, a radar device in the form of a forward-looking radar can also be used in nautica'_ navigation in that the radar data obtained for a forward ..0 sector region in the direction of travel, including objects detected there, are imaged in a two-dimensional, perspective representation on a viewing device. Here, in an image-processing device, a high-resolution, overhead image is converted purely geometrically into a corresponding image having a centered-perspective projection in a quasi-helmsman view, and is displayed on the viewing device_ Elevation information about the scanned, forward sector region can also be incorporated, in a partial 3-D represen~ation, into the image with a centered-perspective projection. in a quasi-helmsman view; elevation information pertaining to the elevation of natural and/or man-made obstacles can also be incorporated in a 3-D representation.
Moreover, according to a further advantageous embodiment of the invention, obstacles that may be present z5 during landing approaches, and project beyond a pradetermined elevation above ground, can be color-coded botr in the map-consistent, overhead image and the quasi-pilot view. Likewise, targets, particularly moving targets, selected during reconnaissance flights can be marked -preferably with color - in both the overhead image and the quasi-pilot view.
An especially practical and advantageous modification of the avionic system according to tre invention lies in the insertion of an artificial horizon in~o the image.
In accordance with an advantageous embodimen~ of the invention, the cen~ered perspective representation in a quasi-pilot view, with the inserted artificial horizon, is also maintained in curved flight patterns. for exaT,p~e, according to a modification of the invention, it is possible to switch between map-consistent, overhead imaging and a centered perspective representation in a quasi-pilot view, with a respective inserted, artificial horizon, on a highly-1.5 sensitive color monitor, even during curved flight patterns.
Likewise, it is possible to switch between different range regions in both the map-consistent, overhead imaging and the centered perspective representation in a quasi-pilot view with the respective inserted, azti=icial :~.ori2on, which :?0 assures an extended-sight mode.
In accordance with a further advantageous embodiment of Che invention, it is also possible to switch the forward-looking radar system between different frequency ranges, for example from the L band (1.3 GHz) across the X band (9.6 .25 GHZ) and up to the Ka band, which is at about 35 GHz, as a function of the respective field of application. :n the switch to the Ka bend, the forwazd-looking radar system can be used to recognize high-voltage lines, for example, or wire fences used for bordering areas.
In accordance with an advantageous embodiment of the invention, she centered perspective representation in a quasi-pilot view, with or with4ut an inserted artificial S horizon. can be automatically adapted to the flight altitude arid flight speed.
As further advantageous modifications of the invention, additional data or information Can be inserted into the centered perspective representation in a aaasi-pilot view, :,0 such as distances to marked targets. the altitude of marked targets or a marking of moving targets, resulting in an MTI
(Moving Target Indication) mode. Moving targets can also be marked.
Within the =ramework of the invention, it is also 15 possible to combine the centered perspective representation in a quasi-pilot view with further operating modes, such as weather radar, surveillance radar or the 1'_ke.
Because of the high resolution capability attainable with the use of the avionic system of the invention, a 20 device that warns of obstacles can be actuated or initiated, for example, with the aid of received and purposeiu~ly selected data. It is also possible to produce a so-called head-up display representation.
In accordance with a further advantageous embodiment of 25 the invention, in addition to the image of the earth's surface. information pertaining to the elevation above around of natural and/or artificial obstacles can be inclLded in the quasi-pilot view.
The high-resolution graphic representation of the flight sector lying ahead in the flight direction that can be attained with the use of the forward-looking radar system permits an application for flights within civil and military scopes; thus, for example, autonomous landing approaches, purposeful, precise load jettison'_na and the like can be executed Yeliably.
BRIEF DESCRIPT:ON -OF THE DRAWINGS
The invention is described in derail below by way of :LO various embodiments, with reference to the attached draw_r.gs, which show in:
Ficr. _ a schematic representat~_on of an antenna constructed from a plurality of adjacent individual radiators, for use in forward-looking i5 radar;
Fig. 2 a schematic representation of an illuminating geometry, as results from an aircraft flying in a predetermined flight direction:
Fig. 3 a plan view, in a map-consistent representation, 2C of a portion of a runway and its immediate vicinity from a flight altitude of 1000 m:
Fig. 4 a centered-perspective representation in a quasi-pilot view of the same portion of the runway and its immediate vicinity, corresponding to the 25 representation of fig. 3;
Fig. S again, a plan view, in a map-consistent representation; of n portion of a runway. but from - l0 -a flight altitude of 300 m;
Fig. 6 a centered-perspective representation in a quasi-pilot view, corresponding to the map-consistent representation of Fig_. 3; and Figs. 7 & 8 in :nap-consistent representations, respectively a plan view of a tree formation from a flight altitude o_' 100 m and special markings for regions having a certain elevation above gro::.~.d ( Fig . 8 ) .
;) ~MHODIMENTS O~' THE INVENTION
Eig. 1 scl~.ematically shows n individual radiators in the form of horn antennas 10 disposed in a straight-line, adjacent antenna arrangement 1. In an arrangement not shown in detail, the antenna arrangement 1 is rigidly mounted to :~ an aircraft - which is shown on a greatly-reduced scale -specifically transversely to its flight direction, which is indicated by an arrow, such that the primary radiation direction of the horn antennas 10 is orien~ed in the flight direction.
c0 According to DE 40 07 611, only one individual radiator, i.e., one horn antenna 10, transmits; however, all of the other individual elements, for example i:~ the form of the horn antennas 10, then receive. .n contrast, in D~ 40 07 612, the n _ndividual radiators are used consecutively a?5 from the first to the nth element to transmit, then to receive.
The rev data can be processed in a manner similar to a.
the known SAR principle, with a synthetic aperture in DE 90 07 611 being replaced by half the spacing or, in DC 40 07 612, by the spacing between the first and the nth individual radiators of the horn-antenna arrangement.
During the processing, the respect=ve signal is correlated according to amplitude and phase, as a function of the range, with a conjugated complex reference function, not disclosed in detail here. A decisive factor. however, is chat. at each individual element 10, the received signal has a phase that differs from the tra:.smitted pulse due to the di=ferent location between the transmitter and receiver.
This means thzt, in incoherent operation, the phase relationship be~ween the individual elements must be constant and known iDE 90 07 6i1>. Because coherent ~5 operation is employed in the transmitting and receiving branches in DE 40 07 612, the relative phase position of the signals received at different locatio-~s must be known in this operating mode.
Tf the spacing between the n individual radiators 10 is :20 ox, this spacing can be expressed by px = 1 = h/O in DE 40 07 611; or Ox = I/2 = x/20 in DE 40 07 612, where I is the aperture length of each individual radiator, is the wavelength and ~ is the illumination angle. The 25 illumination ang~e O is shown schematically in the illumination geometry in Fig. 2.
If the distance between a target point T and an individual radiator 10 of the respective antenna arrangement is represented by r, a. can be inferred from the schematic representation of Fig. 2, the distance r can be expressed by:
R~ + Ca-x)Z , with a representing zhe-distance between the central antenna axis O and a point targat T, x representing the distance between the central an~enna axis O and an individual radiator 10 and R representing the range-gate spacing, which can also be inferred in detail fzom the schematic representation of Fig. 2.
.LO Fig. 3 shows a map-consistent, o~rerhead view produced with a relatively-short antenna from a flight altitude of 1000 m in the X band. a portion of a runway can be identified approximately in the center of the figure.
Fig. 9 Shows the corresponding, centered-perspective .5 representation in a quasi-pilot view, which has been obtained through a corresponding conversion of the map-consistent representation in the overhead view of Fig. 3.
The upper region of Fig. 4 shows a portion of the runway, while the lower region shows the area located in front of 20 the runway, seen in the flight direction. In Fig. 9. an inserted artificial horizon, :or example in the form of a black bar, is shown along the upper longitudinal edge of the representation.
In Figs. 3 and 4, the illumination angle i5 60° in the 25 azimuth direction, and the depression angle ranges from 19°
to 60°. The resolution in the azimuth direction is 10 m in the close range and 35 m in the remote range, while the resolution in the elevation direction is 3 m.
Fig. 5 shows a portion of the same runway in a map-consistent, overhead view, in this case from a flight altitude o~ 300 m_ Eig. 6 shows the centered-perspective representation in a quasi-pilot view. An insertea arLi=yc~a,l. 11VL14V11, iwt example in the form of a black bar, is shown along the upper lo..~.gitudizal edge.
'LO Fig. 7 shows a map-consistent, overhead view of a tree and bush formation at an X-band frequency of 9.6 GKz and from a flight altitude of 100 m.
Fig. 8 shows the same cutout as in Fig. ~. In the practical embodiment, colored markings indicate regions that project at an elevation of, for example, more than 3 m above the surrounding =egion, i.e., 3 m above the ground-;n Figs. 7 and 8, as in Figs. 3 and 4, the illumination angle is 60° in the azimuth direction, and zhe depression angle ranges ~rom 14° to 60°. In Figs. 7 and 8, the surface area resolution is 0.6 mZ in the near range, and 1.1 mZ in the remote range.
Claims (16)
1. An avionic system for aircraft, employing an on-board radar device, which displays a two-dimensional, perspective image of the obtained radar data of a sector region lying ahead in a flight direction, including objects that can be detected there, on a viewing device, characterized in that the radar device is a forward-looking radar that, corresponding to its basic operating mode, produces a high-resolution, map-consistent, overhead image of received radar data, using the SAR (Synthetic Aperture Radar) principle. or a processing principle similar to SAR, and a digital image-processing device is provided, in which the map-consistent, overhead view produced by the radar device is converted purely geometrically into a corresponding image with a centered-perspective projection in a quasi-pilot view, which is then displayed on the viewing device.
2. The avionic system according to claim 1, characterized in hat the system switches between a first display mode, in which the sector is imaged in a map-consistent, overhead view, aid a second display mode, in which the sector is imaged in the centered-perspective projection in a quasi-pilot view on the viewing device.
3. The anionic system according to claim 1 or 2, characterized in that elevation information pertaining to the terrain of the scanned sector region is incorporated, in a partial 3-D representation, into the represented image.
-18-9. The avionic system according to clam 3, characterized in gnat the elevation information is generated directly according to the interferometric principle.
5. The avionic system according to claim 3 or 4, characterized in that elevation information pertaining 20 the elevation above ground of natural and/or man-made obstacles is incorporated, in a partial 3-D representation, into the image with a centered-perspective projection.
6. The avionic system according to claim 4 or 5, characterized in what obstacles that may be present during landing approaches, and exceed a predetermined elevation above ground, are color-coded in the image.
7. The avionic system according to claim 4 or 5, characterized in that selected targets, particularly moving targets, selected during reconnaissance flights are marked in the image.
6. The avionic system according to one of claims 1 through 3, characterized in that color-coding is provided in the image.
9. The avionic system according to claim 1 or 2, characterized in that an artificial horizon is inserted into the image.
10. The avionic system according to claim 9, characterized in that the centered-perspective representation in a quasi-pilot view with an inserted artificial horizon is also maintained in curved flight patterns.
11. The avionic system according to claims 2 and 9, characterized in that the capability of switching between a map-consistent overhead view and a centered-perspective representation in a quasi-pilot view, respectively with an inserted artificial horizon, is also maintained in curves flight patterns.
12. The avionic system according to one of the foregoing claims, characterized in thaw the centered-perspective projection in a quasi-pilot view with an inserted artificial horizon. can be switched between different ranges.
13. The avionic system according to one of the foregoing claims, characterized in that the frequency range (L band Lo Ka band) of the forward-looking radar is adapted as a function of the respective area of application.
14. The avionic system according to one of the foregoing claims, characterized in that the centered-perspective representation in a quasi-pilot view, with an inserted artificial horizon, is adapted automatically to the flight altitude and the flight speed.
15. The avionic system according to one of the foregoing claims. characterized in that additional information or data is or are imaged for the centered-perspective representation in a quasi-pilot view.
16. The avionic system according to one of the foregoing claims, characterized in that the centered-perspective representation in a quasi-pilot view is combined with one or more operating modes, such as weather radar, surveillance radar or the like.
Applications Claiming Priority (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19731169A DE19731169A1 (en) | 1997-07-21 | 1997-07-21 | Aircraft avionic system using onboard radar |
| DE19731169.5 | 1997-07-21 | ||
| DE19731263A DE19731263A1 (en) | 1997-07-21 | 1997-07-21 | Aircraft avionic system using onboard radar |
| DE19731262A DE19731262A1 (en) | 1997-07-21 | 1997-07-21 | Aircraft avionic system using onboard radar |
| DE19731262.4 | 1997-07-21 | ||
| DE19731263.2 | 1997-07-21 | ||
| PCT/EP1998/004537 WO1999005541A1 (en) | 1997-07-21 | 1998-07-21 | Avionic system intended for use in aircrafts and involving use of an on-board radar equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2297177A1 true CA2297177A1 (en) | 1999-02-04 |
Family
ID=27217553
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002297177A Abandoned CA2297177A1 (en) | 1997-07-21 | 1998-07-21 | Avionic system intended for use in aircrafts and involving use of an on-board radar equipment |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0998682A1 (en) |
| CA (1) | CA2297177A1 (en) |
| WO (1) | WO1999005541A1 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4940987A (en) * | 1989-01-30 | 1990-07-10 | Frederick Philip R | Automatic horizontal and vertical scanning radar |
| US5179377A (en) * | 1990-12-31 | 1993-01-12 | Honeywell Inc. | Tcas view display format with horizontal trend |
| US5654890A (en) * | 1994-05-31 | 1997-08-05 | Lockheed Martin | High resolution autonomous precision approach and landing system |
| CA2153012A1 (en) * | 1994-06-30 | 1995-12-31 | Leo H. Hui | Low visibility imaging radar system |
-
1998
- 1998-07-21 CA CA002297177A patent/CA2297177A1/en not_active Abandoned
- 1998-07-21 WO PCT/EP1998/004537 patent/WO1999005541A1/en not_active Application Discontinuation
- 1998-07-21 EP EP98941385A patent/EP0998682A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| WO1999005541A1 (en) | 1999-02-04 |
| EP0998682A1 (en) | 2000-05-10 |
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