CA1083338A - Photo electronic astro compass - Google Patents
Photo electronic astro compassInfo
- Publication number
- CA1083338A CA1083338A CA325,787A CA325787A CA1083338A CA 1083338 A CA1083338 A CA 1083338A CA 325787 A CA325787 A CA 325787A CA 1083338 A CA1083338 A CA 1083338A
- Authority
- CA
- Canada
- Prior art keywords
- light
- radiant body
- instrument
- light sensitive
- sensitive devices
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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
- G01S3/00—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received
- G01S3/78—Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received using electromagnetic waves other than radio waves
- G01S3/782—Systems for determining direction or deviation from predetermined direction
- G01S3/783—Systems for determining direction or deviation from predetermined direction using amplitude comparison of signals derived from static detectors or detector systems
- G01S3/784—Systems for determining direction or deviation from predetermined direction using amplitude comparison of signals derived from static detectors or detector systems using a mosaic of detectors
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
Photo Electronic Astro Compass Abstract In an instrument for navigation, it is known to have a plurality of light sensitive devices contained in such manners as to be illuminated in only one concentrated area by a radiant body and means for electrically con-verting the output of the said light sensitive devices to a microprocessor for detecting the angle of the radiant body.
Description
1~83338 Photo Electronic Astro Com~ass ,_ This invention relates t~ a device for reading the angle of a radiant body, and more particularly to a navigational aid.
In Transport Canada's Flight Information Manual 1976 Civil Aeronautics Page 2-13 is stated, "In response to a need for the provision of directional information simply and to within one degree (1) the Legislation and ~tan-dards Branch of Civil Aeronautics has arranged for the development of tables from which the Sun's True Bearing can be quickly extracted knowing only the date, Local Civil Time and approximate latitude and longitude". The publi-cation is entitled "Finding the Sun's True Bearing precomputed tables", and states the following:-From aviation's earliest days, pilots of aircraft havs been con-cious of the need for accurate directional information. The developmen-t of the magnetic and gyro compass has, for general purposes, kept pace with aviation needs in most areas of the world. ~light operations in Northern Canada, ho~ever, present problems which are unique by virtue o~ the posi-tion of the North Magnetic Pole.
Navigation by referencs to the magnetic meridian in this general area poses practical problems in taking account of the large changes in magnetic variation and the errors which occur in aircraft magnetic compass systems due to the reduction in the horizontal directional properties of the earth's magnetic field as one nears the North Magnetic Pole".
Radio Navigational Aids are very limited and landmarks few and far ;~
between in these northern areas further increasing navigational problems.
Close to the Magnetic Pole, the earth's Magnetic Lines of Force dip vertically to~ards the Pole. The compass needle lies in a horizontal plane, and as the strength of the horizontal component of the sarth's magnetic field tends to disappear in the close vicinity of the Pole, the magnetic compass loses its ability to point the ~ay, and becomes anything but a de-pendable companion. In a large area of Northern Canada the magnetic compass is therefore unreliable. Within this area, called the Northern Domestic Airspace, ~IOT regulations require that airplanes weighing 12,000 lbs. or .. . . . . ... .
~83338 over must be fitted with an Astro Compass or some other means of determining direction that is not dependent on a magnetic source. The Astro Compass is not influenced by the earth's Magnetic Field, but indicates direction with refer-ence to the Sun, Moon~ Planets or Stars. These heavenly bodies ha~e been man's guiding beacons in the skies since time immemorial. The examinations for Commercial, Senior Commercial and Transport Pilot licenses in Canada require a knowledge of the Astro Compass.
The ASTRO COl~ASS is an instrument designed to enable a pilot or naviga-tor to determine the True Heading of his airplane. tIt can also be used to take a bearing on an abject.) In the simplest possible terms, the As~ro Compass is a Bearing Plate with a movable Sighting Device mounted above it. The bearing of a heavenly body can be set on the bearing plate, and when the movable sights are properly aligned on the heavenly body, the North Mark on the bearing plate will coin-cide with True North. The bearing plate can now be read off against a Lubber Line ~aligned in the fore and aft axis of the airplane) to indicate the TRUE
B ADING. The Directional Gyro can now be set to the True Heading and the air-plane steered with reference to the Directional Gyro in lieu of the magnetic compass.
How do you find the true bearing (or aæimuth) of the heavenly body to set on the bearing plate? The Astro Compass automatically does this for you pro-vided you supply it with the following information:-1. Your Latitude.
In Transport Canada's Flight Information Manual 1976 Civil Aeronautics Page 2-13 is stated, "In response to a need for the provision of directional information simply and to within one degree (1) the Legislation and ~tan-dards Branch of Civil Aeronautics has arranged for the development of tables from which the Sun's True Bearing can be quickly extracted knowing only the date, Local Civil Time and approximate latitude and longitude". The publi-cation is entitled "Finding the Sun's True Bearing precomputed tables", and states the following:-From aviation's earliest days, pilots of aircraft havs been con-cious of the need for accurate directional information. The developmen-t of the magnetic and gyro compass has, for general purposes, kept pace with aviation needs in most areas of the world. ~light operations in Northern Canada, ho~ever, present problems which are unique by virtue o~ the posi-tion of the North Magnetic Pole.
Navigation by referencs to the magnetic meridian in this general area poses practical problems in taking account of the large changes in magnetic variation and the errors which occur in aircraft magnetic compass systems due to the reduction in the horizontal directional properties of the earth's magnetic field as one nears the North Magnetic Pole".
Radio Navigational Aids are very limited and landmarks few and far ;~
between in these northern areas further increasing navigational problems.
Close to the Magnetic Pole, the earth's Magnetic Lines of Force dip vertically to~ards the Pole. The compass needle lies in a horizontal plane, and as the strength of the horizontal component of the sarth's magnetic field tends to disappear in the close vicinity of the Pole, the magnetic compass loses its ability to point the ~ay, and becomes anything but a de-pendable companion. In a large area of Northern Canada the magnetic compass is therefore unreliable. Within this area, called the Northern Domestic Airspace, ~IOT regulations require that airplanes weighing 12,000 lbs. or .. . . . . ... .
~83338 over must be fitted with an Astro Compass or some other means of determining direction that is not dependent on a magnetic source. The Astro Compass is not influenced by the earth's Magnetic Field, but indicates direction with refer-ence to the Sun, Moon~ Planets or Stars. These heavenly bodies ha~e been man's guiding beacons in the skies since time immemorial. The examinations for Commercial, Senior Commercial and Transport Pilot licenses in Canada require a knowledge of the Astro Compass.
The ASTRO COl~ASS is an instrument designed to enable a pilot or naviga-tor to determine the True Heading of his airplane. tIt can also be used to take a bearing on an abject.) In the simplest possible terms, the As~ro Compass is a Bearing Plate with a movable Sighting Device mounted above it. The bearing of a heavenly body can be set on the bearing plate, and when the movable sights are properly aligned on the heavenly body, the North Mark on the bearing plate will coin-cide with True North. The bearing plate can now be read off against a Lubber Line ~aligned in the fore and aft axis of the airplane) to indicate the TRUE
B ADING. The Directional Gyro can now be set to the True Heading and the air-plane steered with reference to the Directional Gyro in lieu of the magnetic compass.
How do you find the true bearing (or aæimuth) of the heavenly body to set on the bearing plate? The Astro Compass automatically does this for you pro-vided you supply it with the following information:-1. Your Latitude.
2. The Local Hour Angle of the body.
3. The Declination of -the body.
Your position, in latitude and longitude, is that assumed by yourself, based on your own D.R. navigation.
The position of the Sun, Stars and other as-tronomical bodies can be ac-curately predicted for any given moment of time. They are recorded in a handy volume called the AIR A~MANAC. By opening the Air Almanac to the Greenwich date, hour and minute of time on which you wish to check your True Heading, you can look up the Greenwich Hour Angle and the Declination .. . ..
108333~
of the Sun, Moon, Aries, or the particular Planet you wish to sight on.
The Sidereal Hour Angle and Declination of any navigation Star can similarly be found. (From The Ground Up, Sandy A. F. MacDonald's) The Astro Compasses are, however, too large and clumsy for general aviation use, and impractical since they must be operated manually by a pilot in flight.
It is, therefore, the object of the present invention to provide a new instrument for measuring the direction of a radiant body, and more partic-ularly to a new navigational aid which is relatively small and gives directly the direction or position of an aircraft without manual operation by the pilot. The instrument in accordance with the present invention comprises an apparatus having a plurality of wells oriented at different angles in both a horizontal and a vertical plane toward the sky, a light sensitive device at the base of each well and adapted to be illuminated by the radiant body depending on the position of the radiant body, and means for electrically connecting the output of the light sensitive devices to a microprocessor for detecting the angle of the radiant body.
In an alternative embodiment of the invention, the instrument comprises a light tight container having a plurality of light sensitive devices located on the bottom and a small hole in the ceiling to allow a shaft of light originating from the radiant body to fall on some of the light sensitive -devices depending on the angular position of the radiant body and means for electrically connecting the output of the light sensitive devices to a microprocessor for detecting the angle of the radiant body.
The invention will now be disclosed, by way of examples, with reference to the accompanying drawings in which:
Figure 1 is a cross section of Tube and Photo Cells Design.
Figure 2 is a cross section of ~alf Sphere and Fiber Optic Design.
Figure 3 is a cross section of Saucer Design.
Figure 4 is a cross section showing the light effect on a tube and photo cell design.
Referring to figure 1, a dome of many light tight tubes 10 are mounted together in such a manner that they all point in different directions through-.
~083338 out 360 of the hori~ontal plane and throughout about 180 in a vertical plane.All tubes have a co~non focal point below or under the instrument. At the central or core end of the tubes are inserted photo cells 12 in a ligm tight manner. Flat black paint on the interior sides of the tubes may help in cutting down bounce light reaching the photo cells from the open end of tubes.
Large numbers of photo cells and tubes would increase the number of angles the instrument is capable of measuring~ making it more accurate. Len~th and inside diameter would also effect angle measurement. Photo cell wires 14 would lead to a microprocessor (not shown) informing the system of the sun's angle indicated by the strongest signal received. Such microprocessors are well known and need not be disclosed in detail.
Figure 2 shows a design which may be much superior in being much more compact and more precise and ~ith half the number of leads to deal with, not to mention no power source required for this section. As ~hown in figure 2 the cross section shows a sphere 20 with the central core remo~ed. As an example the sphere could be solid aluminium. Fine fiber optical size (hair si~e) holes 22 are drilled at many angles throughout the sphere all leading to a common central point. In the core or interior ends of holes 22 photo optic leads 24 are plugged tor glued) in the bottom of each hole in a llgm tight manner. The photo optic leads lead off to a microprocessor ~not shown).
At the microprocessor the strongest signal would determine the sun's angle, and combined with the microprocessor's internal clock, date, time and sun's angle pass through a flow chart, producing a read ouk in a cockpit indicating the aircrafts heading. Such microprocessors are also well known.
Figure 3 shows a design which is quite different from the preceding and may be superior in simplicity of construction. Photo cells 30 are closel~
mounted in a saucer shape body 32 with a lid 34 across the top enclosing the area making it light tight except for a pin hole 36 in the central lid allow-ing a beam of light to penetrate the area hitting a photo cell in a straight line between the light source and the hole, and itself. Agaln wires 3~ tor optical fibers) would lead to a microprocessor. IDue to cons~ruct,ion design some angles are be~ond it's range and would not be detectable. This problem .
~83338 could be easily overcome by the use of more than one instrument for the particular application, each pointing differently. (On a helicopter, more than one instrument would be preferable to overcome the obstruction of the light path between the instrument and main rotor mast.) Figure 4 shows the light effect on a cross section of an instrument designed with tubes and photo cells. The light source casts shadows over all photo cells except those of which the wells are directed in line with the light source. The well directly oriented to the light source allows the light to penetrate to its bottom, where the accompanying photo cell becomes illuminated allowing a current to flow through it.
It can be clearly seen that many designs could be developed in different combinations of photo cells and fiber optics, tubes and half spheres, and/or similar to the saucer design in order to read the angle of a radiant body.
In service, light would stimulate a particular photo cell or optical fiber of the instrument. This would allow a current to flow or light to be carried from that particular well, indicating the angle of the radiant body relative to the instrument in the computer system. Through a flow chart of , sorts combined with other information such as that of an internal clock, the microprocessor would give a readout to a pilot in his aircraft in degrees true indicating the headlng of the aircraft.
The apparatus was originally invented with the idea of application to rotor wing aircraft (helicopters) measuring the sun's angle. But its application is clearly not limited to these, but could be applied to fix wing airplanes, ships, ground vehicles and space craft, to measure angles of any radiant body for navigational or other purposes. It may be applied possibly for surveying, and also be specialized to be sensitive to particular light by the introduction of filters, lenses or devices sensitive to the particular light spectrum desired. (Infrared to ultraviolet). In designing the instrument sensitive to ultraviolet or polarized light, the apparatus may be functional even in overcast weather, because these forms of light vibrations are capable of penetrating clouds, though overcast weather is, perhaps, less ~08~33~3 i common in the extreme north where the cold does not allow the air to hold moisture.
For aviation purposes, if need be, an electrical system of sorts could allow a readout only during straight and level flight.
a) DIRECTIONAL: In this application, the instrument would be set up with its computer system to give directional information only.
B) LOCATIVE: In this application, the computer system would be more complex in its flow charts and informational inputs. This system would give it the ability to produce a readout in an aircraft's cockpit indicating the aircraft's location on the earth's surface in degrees, minutes and seconds of longitude and latitude.
Your position, in latitude and longitude, is that assumed by yourself, based on your own D.R. navigation.
The position of the Sun, Stars and other as-tronomical bodies can be ac-curately predicted for any given moment of time. They are recorded in a handy volume called the AIR A~MANAC. By opening the Air Almanac to the Greenwich date, hour and minute of time on which you wish to check your True Heading, you can look up the Greenwich Hour Angle and the Declination .. . ..
108333~
of the Sun, Moon, Aries, or the particular Planet you wish to sight on.
The Sidereal Hour Angle and Declination of any navigation Star can similarly be found. (From The Ground Up, Sandy A. F. MacDonald's) The Astro Compasses are, however, too large and clumsy for general aviation use, and impractical since they must be operated manually by a pilot in flight.
It is, therefore, the object of the present invention to provide a new instrument for measuring the direction of a radiant body, and more partic-ularly to a new navigational aid which is relatively small and gives directly the direction or position of an aircraft without manual operation by the pilot. The instrument in accordance with the present invention comprises an apparatus having a plurality of wells oriented at different angles in both a horizontal and a vertical plane toward the sky, a light sensitive device at the base of each well and adapted to be illuminated by the radiant body depending on the position of the radiant body, and means for electrically connecting the output of the light sensitive devices to a microprocessor for detecting the angle of the radiant body.
In an alternative embodiment of the invention, the instrument comprises a light tight container having a plurality of light sensitive devices located on the bottom and a small hole in the ceiling to allow a shaft of light originating from the radiant body to fall on some of the light sensitive -devices depending on the angular position of the radiant body and means for electrically connecting the output of the light sensitive devices to a microprocessor for detecting the angle of the radiant body.
The invention will now be disclosed, by way of examples, with reference to the accompanying drawings in which:
Figure 1 is a cross section of Tube and Photo Cells Design.
Figure 2 is a cross section of ~alf Sphere and Fiber Optic Design.
Figure 3 is a cross section of Saucer Design.
Figure 4 is a cross section showing the light effect on a tube and photo cell design.
Referring to figure 1, a dome of many light tight tubes 10 are mounted together in such a manner that they all point in different directions through-.
~083338 out 360 of the hori~ontal plane and throughout about 180 in a vertical plane.All tubes have a co~non focal point below or under the instrument. At the central or core end of the tubes are inserted photo cells 12 in a ligm tight manner. Flat black paint on the interior sides of the tubes may help in cutting down bounce light reaching the photo cells from the open end of tubes.
Large numbers of photo cells and tubes would increase the number of angles the instrument is capable of measuring~ making it more accurate. Len~th and inside diameter would also effect angle measurement. Photo cell wires 14 would lead to a microprocessor (not shown) informing the system of the sun's angle indicated by the strongest signal received. Such microprocessors are well known and need not be disclosed in detail.
Figure 2 shows a design which may be much superior in being much more compact and more precise and ~ith half the number of leads to deal with, not to mention no power source required for this section. As ~hown in figure 2 the cross section shows a sphere 20 with the central core remo~ed. As an example the sphere could be solid aluminium. Fine fiber optical size (hair si~e) holes 22 are drilled at many angles throughout the sphere all leading to a common central point. In the core or interior ends of holes 22 photo optic leads 24 are plugged tor glued) in the bottom of each hole in a llgm tight manner. The photo optic leads lead off to a microprocessor ~not shown).
At the microprocessor the strongest signal would determine the sun's angle, and combined with the microprocessor's internal clock, date, time and sun's angle pass through a flow chart, producing a read ouk in a cockpit indicating the aircrafts heading. Such microprocessors are also well known.
Figure 3 shows a design which is quite different from the preceding and may be superior in simplicity of construction. Photo cells 30 are closel~
mounted in a saucer shape body 32 with a lid 34 across the top enclosing the area making it light tight except for a pin hole 36 in the central lid allow-ing a beam of light to penetrate the area hitting a photo cell in a straight line between the light source and the hole, and itself. Agaln wires 3~ tor optical fibers) would lead to a microprocessor. IDue to cons~ruct,ion design some angles are be~ond it's range and would not be detectable. This problem .
~83338 could be easily overcome by the use of more than one instrument for the particular application, each pointing differently. (On a helicopter, more than one instrument would be preferable to overcome the obstruction of the light path between the instrument and main rotor mast.) Figure 4 shows the light effect on a cross section of an instrument designed with tubes and photo cells. The light source casts shadows over all photo cells except those of which the wells are directed in line with the light source. The well directly oriented to the light source allows the light to penetrate to its bottom, where the accompanying photo cell becomes illuminated allowing a current to flow through it.
It can be clearly seen that many designs could be developed in different combinations of photo cells and fiber optics, tubes and half spheres, and/or similar to the saucer design in order to read the angle of a radiant body.
In service, light would stimulate a particular photo cell or optical fiber of the instrument. This would allow a current to flow or light to be carried from that particular well, indicating the angle of the radiant body relative to the instrument in the computer system. Through a flow chart of , sorts combined with other information such as that of an internal clock, the microprocessor would give a readout to a pilot in his aircraft in degrees true indicating the headlng of the aircraft.
The apparatus was originally invented with the idea of application to rotor wing aircraft (helicopters) measuring the sun's angle. But its application is clearly not limited to these, but could be applied to fix wing airplanes, ships, ground vehicles and space craft, to measure angles of any radiant body for navigational or other purposes. It may be applied possibly for surveying, and also be specialized to be sensitive to particular light by the introduction of filters, lenses or devices sensitive to the particular light spectrum desired. (Infrared to ultraviolet). In designing the instrument sensitive to ultraviolet or polarized light, the apparatus may be functional even in overcast weather, because these forms of light vibrations are capable of penetrating clouds, though overcast weather is, perhaps, less ~08~33~3 i common in the extreme north where the cold does not allow the air to hold moisture.
For aviation purposes, if need be, an electrical system of sorts could allow a readout only during straight and level flight.
a) DIRECTIONAL: In this application, the instrument would be set up with its computer system to give directional information only.
B) LOCATIVE: In this application, the computer system would be more complex in its flow charts and informational inputs. This system would give it the ability to produce a readout in an aircraft's cockpit indicating the aircraft's location on the earth's surface in degrees, minutes and seconds of longitude and latitude.
Claims (4)
1. An instrument for finding the direction of a radiant body, comprising a plurality of light sensitive devices mounted within the instrument, means located within the instrument to allow a shaft of light to fall on a limited number of said light sensitive devices depending on the angular position of the radiant body, and means for electrically connecting the light sensitive devices to a microprocessor for detecting the direction of the radiant body.
2. An instrument for finding the direction of a radiant body comprising a plurality of wells oriented in different directions on both a horizontal and vertical plane so as to point to a common centre, a light sensitive device located at the base of each well and adapted to be illuminated by the radiant body depending on the angular position of the radiant body, and means for electrically connecting each light sensitive device to a microprocessor for detecting the direction of the radiant body.
3. An instrument for finding the direction of a radiant body comprising an enclosed light tight container, a plurality of light sensitive devices located on the bottom of said container, a small hole in the ceiling of the container to allow a shaft of light to penetrate the chamber and fall on a limited number of said light sensitive devices depending on the angular position of the radiant body, and means for electrically connecting the light sensitive devices coming out the bottom of the container to a microprocessor for detecting the direction of the radiant body.
4. An instrument as claimed in any of claims 1, 2 and 3, wherein said light-sensitive devices are composed of either optical fibers for trans-mitting light from the instrument or photocells to directly convert the light signal to an electrical signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA325,787A CA1083338A (en) | 1979-04-17 | 1979-04-17 | Photo electronic astro compass |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA325,787A CA1083338A (en) | 1979-04-17 | 1979-04-17 | Photo electronic astro compass |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1083338A true CA1083338A (en) | 1980-08-12 |
Family
ID=4114000
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA325,787A Expired CA1083338A (en) | 1979-04-17 | 1979-04-17 | Photo electronic astro compass |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1083338A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0047084A1 (en) * | 1980-09-02 | 1982-03-10 | Dow Corning Corporation | Solar collection system |
| EP0114053A2 (en) * | 1983-01-13 | 1984-07-25 | Alcatel N.V. | Device for determining the angle of incidence of optical radiation |
| WO1998022833A1 (en) * | 1996-11-19 | 1998-05-28 | Tracor Aerospace, Inc. | Fiber optic guidance system for laser guided missiles |
-
1979
- 1979-04-17 CA CA325,787A patent/CA1083338A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0047084A1 (en) * | 1980-09-02 | 1982-03-10 | Dow Corning Corporation | Solar collection system |
| EP0114053A2 (en) * | 1983-01-13 | 1984-07-25 | Alcatel N.V. | Device for determining the angle of incidence of optical radiation |
| EP0114053A3 (en) * | 1983-01-13 | 1985-10-23 | International Standard Electric Corporation | Device for determining the angle of incidence of optical radiation |
| US4625108A (en) * | 1983-01-13 | 1986-11-25 | International Standard Electric Corporation | Device for determining the direction of incident optical radiation |
| WO1998022833A1 (en) * | 1996-11-19 | 1998-05-28 | Tracor Aerospace, Inc. | Fiber optic guidance system for laser guided missiles |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Biezad | Integrated navigation and guidance systems | |
| Hofmann-Wellenhof et al. | Navigation | |
| Sasaki et al. | Launch and observation program of the experimental geodetic satellite of Japan | |
| US3283408A (en) | Meridian and latitude indicator | |
| CA1083338A (en) | Photo electronic astro compass | |
| US2961191A (en) | Automatic one-star navigational directors | |
| CN109974692A (en) | A kind of hidden environment astronomical positioning system and method based on neutrino signal | |
| US5477470A (en) | Real-time digital orientation device | |
| US3374549A (en) | Orientator | |
| Canas et al. | Coutinho's Method for the Altitude | |
| Draper | Navigation-from canoes to spaceships | |
| Horsfall | Stellar inertial navigation | |
| Moody | The pfund sky compass | |
| Wrigley | An investigation of methods available for indicating the direction of the vertical from moving bases | |
| Cade | The Use of Radio Sextants in Automatic Navigation Systems | |
| Lawrence | An outline of inertial navigation | |
| Ovcharenko et al. | Aircraft systems and equipment | |
| Pleter | Directions, Azimuths, Horizon | |
| Miner | AIRCRAFT POSSIBILITIES FOR TRUE NORTH GYRO COMPASS | |
| Beij | Astronomical Methods in Aerial Navigation | |
| Hagger | Air navigation in high latitudes1 | |
| Gibson | Cave radiolocation | |
| und Geomatik | Investigations to digitizing of the gyro oscillation swing by a line camera | |
| Zhilisbayeva et al. | Changing the magnetic field intensity during the motion of spacecraft | |
| Langston | PRACTICAL ASPECTS OF HIGH SPEED NAVIGATION |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |