DE102010005347A1 - Method for enhancement of position determination in e.g. north pole of earth and in air by mobile navigation device, involves receiving signals emitted by satellites, and using signals for enhancement of position determination - Google Patents

Abstract

The method involves emitting signals (12) for receiving and evaluating by a usage system (14) for position determination. Satellites (10) in a room segment are moved on an earth orbit (16), where the satellites exhibit high eccentricity of about 0.5, a high inclination of 70 degree and an apogee over a polar region (18). The satellites are processed over a pole region outside of an inner radiation zone (20) of a Van Allen radiation belt. The signals emitted by the satellites are received. The signals are used for enhancement of the position determination. An independent claim is also included for a usage system for a satellite navigation system.

Description

The invention relates to a method for improving the position determination with a satellite navigation system according to claim 1, a utilization system according to claim 7 and a satellite according to claim 9.

Global Navigation Satellite Systems (GNSS) are used to locate and navigate the Earth and in the air. GNSS systems, such as the European Satellite Navigation System under construction (hereafter also referred to as the Galileo system or Galileo for short), comprise a satellite system comprising a plurality of satellites (space segment), a ground-based receiver system connected to a central computing station ( Ground segment), the Galileo sensor stations (GSS) comprises several ground stations as in the case of Galileo, and use systems that evaluate the satellite signals transmitted by the satellite by radio in particular for navigation and use. From the space segment, each satellite transmits a signal characterizing the satellite, the signal-in-space (SIS). In particular, the SIS contains information about the orbit of the satellite and a time stamp of the time of transmission, which are used to detect the position of a user or utilization system.

However, at latitudes (degrees) that are significantly greater than the inclination of the orbital plane of the satellites, satellite navigation systems usually have relatively poor vertical accuracy because the observation geometries for the utilization systems become very poor. In order to increase the accuracy of the positioning of satellite navigation systems, so-called extension or supplementary systems such as WAAS (Wide Area Augmentation System) and EGNOS (European Geostationary Navigation Overlay Service) are used. These supplementary systems allow a localized increase in positioning accuracy by distributing satellite navigation data correction data to use systems (SBAS: Satellite Based Augmentation System). Although WAAS and EGNOS basically provide data for the latitudes, which are significantly larger than the inclination of the satellite's orbit plane; However, due to the low, sometimes even negative, elevation of the satellites distributing the data from WAAS and EGNOS, the availability of the data is not very high, sometimes even not at all, at these latitudes. Especially due to the global warming and melting of the polar ice masses, however, a reliable, especially accurate position determination and navigation is becoming increasingly important, especially in these latitudes.

Object of the present invention is therefore to improve the position determination with a satellite navigation system such that an accurate position determination and navigation can be achieved even at latitudes (degrees) in which normally the availability of data from satellite navigation systems and the known supplementary systems is not particularly high or is not given at all, how about polar regions.

This object is achieved by a method for improving the position determination with a satellite navigation system having the features of claim 1, by a utilization system having the features of claim 7 and by a satellite having the features of claim 9. Further embodiments of the invention are the subject of the dependent claims.

An essential idea of the invention is to improve the position determination with a satellite navigation system having a space segment with a plurality of first satellites that transmit navigation signals for receiving and evaluation by use systems for position determination, by supplementing the satellite navigation system with a few second satellites, emit signals to improve positional positioning and move on a trajectory having a high eccentricity of at least about 0.5, a high inclination of at least 70 ° and an apogee over a polar region, and those above the other pole region outside the inner ones Radiation zone of the van Allen radiation belt runs. The apogee over the one polar region allows a long residence time over this polar region to be achieved, which, in conjunction with the high inclination of the orbit, provides better reception by utilization systems in the polar region, thereby increasing the utilization systems by means of the second satellites radiated signals can improve their position determination in this polar region, since the observation geometries for the systems of use in this region are now better and therefore the satellite navigation system has a better vertical accuracy. The signals radiated by the second satellites may include correction data for navigation signals radiated by the first satellites, or may themselves be navigation signals.

An embodiment of the invention now relates to a method for improving the position determination with a satellite navigation system comprising a space segment with a plurality of first and second satellites, the signals for receiving and evaluating by utilization systems for the Send out position determination has. The second satellites are orbiting with a high eccentricity of at least about 0.5, a high inclination of at least 70 °, and an apogee over a polar region (FIG. 18 ) and which extends beyond the other pole region outside the inner radiation zone of the van Allen radiation belt. The method comprises the following steps:
Receiving signals emitted by the second satellites and utilizing the signals emitted by the second satellites to improve positioning.

The earth orbit on which the second satellites move has in one embodiment an inclination between about 80 ° and about 100 °, in particular between about 80 ° and about 90 °. It can thereby be achieved that the signals of the second satellites of use systems in the one polar region can be received better than the signals of the first satellites, which circulate on paths with a much lower inclination.

The apogee of the Earth orbit on which the second satellites move may be from about 20,000 to about 50,000 miles. In this way it can be achieved that the second satellites are as long as possible above the one polar region during circulation and good reception of the signals in the one polar region is ensured.

The signals emitted by the second satellites may be coded differently than the signals transmitted by the first satellites, and receiving these signals may comprise switching the decoding to the decoding of those signals. For example, the signals emitted by the second satellites may be coded with a code other than the signals transmitted by the first satellites, so that the signals of the second satellites can only be used if the code used for coding is known to a utilization system. In a utilization system, for example a mobile navigation device, the codes of the signals of the first and the second satellites can be stored for this purpose so that it can use the signals of the second satellites when the signals of the first satellites can only be received weakly, that is to say in particular in the one polar region.

The signals emitted by the second satellites may also be transmitted at a different frequency than the signals transmitted by the first satellites. In particular, the frequency used for the signals of the second satellites may be a frequency not previously used for the transmission of signals from satellite navigation systems, so that the operation of conventional satellite navigation systems is not disturbed by the signals of the second satellites.

The use of the positioning signals emitted by second satellites may be dependent on one or more of the following parameters: received field strength of signals emitted by second satellites; current position of receiving the signals emitted by the second satellites; Authorization to use signals emitted by second satellites. For example, a usage system may decide which signals to use based on the received field strength of the received signals from satellites. For example, if the utilization system in the one polar region receives signals from the second satellites having greater reception field strength than the signals from the first satellites, it may decide to use the signals from the second satellites rather than from the first satellites. Likewise, the utilization system may decide to use signals from the second satellites when it is in one polar region or very close to the one polar region. Finally, the usage may also depend on whether a utilization system is authorized to use the signals of the second satellites, for example by having a corresponding code or key with which the signals of the second satellites can be decoded or decrypted.

Another embodiment of the invention relates to a utilization system for a satellite navigation system, in particular a mobile navigation device, for use with a method according to the invention and as previously described and for the reception of signals of the second satellite and the use of these signals to improve the position determination in a polar region is formed.

The utilization system can also be designed to use the signals emitted by second satellites for the position determination, if
the reception field strength of the signals emitted by the second satellite is greater than the reception field strength of the signals transmitted by the first satellite,
the current position of the utilization system is within the one polar region, and / or
the utilization system has an authorization to use the signals emitted by second satellites.

Another embodiment of the invention relates to a satellite configured for an earth orbit having a high eccentricity of at least about 0.5, a high inclination of at least 70 °, and an apogee over a polar region and those over the other pole region extends outside the inner radiation zone of the van Allen radiation belt, and is further adapted to emit signals to improve the position determination by a utilization system.

The satellite may include an adaptive antenna and further be configured to adjust the illumination angle with emitted signals under which the visible region of the earth appears from the satellite by appropriately driving the adaptive antenna depending on its position over the one polar region.

Further advantages and possible applications of the present invention will become apparent from the following description in conjunction with the embodiments illustrated in the drawings.

In the description, in the claims, in the abstract and in the drawings, the terms and associated reference numerals used in the list of reference numerals recited below are used.

The drawings show in

1 second satellites in earth orbit and the reception of signals from the second satellites to improve positioning in a polar region by use system according to the invention.

In the following description, identical, functionally identical and functionally connected elements may be provided with the same reference numerals. Absolute values are given below by way of example only and are not to be construed as limiting the invention.

In 1 is a part of a constellation of satellites of a satellite navigation system shown, which is also in the polar region 18 in the northern hemisphere of the earth 22 allows a relatively accurate position determination.

In the constellation shown are an orbit 18 first satellite 24 around the Earth 22 and another orbit 16 second satellite 10 around the Earth 22 shown. The constellation shown is only one part of a global navigation satellite system, which usually has not one but several lanes with first satellites, so that a good reception of signals from these satellites in many regions of the earth is guaranteed. In the known and currently in (partial) operating satellite navigation system GPS (Global Positioning System, and NAVSTAR GPS) and GLONASS, however, the reception of signals from satellites and thus the position determination, especially in the polar regions limited and sometimes not at all possible. The resulting impaired position determination in the polar regions is improved by the present invention as follows.

The two in 1 illustrated orbits 26 and 16 have a distinctly different inclination to the equatorial plane 28 the earth 22 , While the orbit 26 the first satellite 24 has a typical inclination of around 60 °, the orbit 16 the second satellite 10 a much greater inclination of at least 70 °, in particular between about 80 ° and about 100 °, in particular between about 80 ° and about 90 °. This will increase the visibility of the second satellites 10 over the polar regions in the north and south of the earth 22 against the visibility of the first satellites 24 improved over these regions.

Furthermore, the orbit differs 16 from orbit 26 in that orbit 16 an apogee about 20,000 to about 50,000 km above the polar region 18 possesses, and has a perigee over the polar region of the southern hemisphere, which is outside the inner radiation zone 20 of the van Allen radiation belt at a height significantly below 10000 km. An orbit with such different Apogee and perigee is achieved by the fact that the web 16 has a high eccentricity of at least about 0.5.

One in the polar region 18 used utilization system 14 , especially a mobile navigation system, is due to the higher inclined orbit 16 the second satellite 10 capable of that from the second satellite 10 emitted signals 12 better than the first satellites 24 to receive transmitted signals. Because of over the polar region 18 located apogee of the orbit 16 is the residence time of the second satellites 10 larger than over the polar region of the southern hemisphere. As the illumination angle below which the visible area of the earth 22 from a second satellite 10 appears clearly during the dwell time of the second satellites 10 over the polar region 18 can change the second satellites own 10 adaptive antennas with which the illumination angle can be adjusted to be above the polar region during the dwell time 18 changes as little as possible and good visibility of the second satellite 10 emitted navigation signals 12 for use systems 14 in the polar region 18 can be guaranteed.

The second satellites 10 emitted signals 12 can use navigation signals like the signals of the first satellites 24 or transmit correction data similar to that sent out by WAAS or EGNOS to utilization systems.

The second satellites 10 emitted signals 12 can distinguish them from the signals of the first satellites 24 be coded with a different code, so that only specially suitable use systems these signals 12 can decode. Such a utilization system can, for example, upon receipt of the signals 12 the second satellite 10 with sufficient reception field strength to automatically switch the decoding from the signals of the first satellites to the signals of the second satellites. The signals 12 the second satellite 10 can also be on a different frequency than that of the first satellite 24 transmitted signals are transmitted. A utilization system must then receive the signals 12 the second satellite 10 be specially trained. Furthermore, by using a different transmission frequency, if necessary, a disturbance of the transmission of the signals of the first satellite 24 be avoided.

With the present invention, positioning in polar regions of the earth as well as at the south or north pole can be substantially improved over conventional satellite navigation systems. Through the use of highly eccentric and inclined orbits for satellites of a satellite navigation system, the dwell time of satellites located on these orbits can be maximized over polar regions, resulting in improvement of the vertical performance of a satellite navigation system by providing correction data and / or navigation signals.

LIST OF REFERENCE NUMBERS

10

second satellite

12

from the second satellite 10 emitted signals

14

Usage system for the signal 12

16

Earth orbit second satellite 10

18

polar region

20

Inner radiation zone of the van Allen radiation belt

22

earth

24

first satellite

26

Earth orbit of the first satellite 24

28

equatorial plane

Claims (10)

A method for improving position determination with a satellite navigation system comprising a space segment with a plurality of first and second satellites ( 10 . 24 ), the signals ( 12 ) for receiving and evaluating by use systems ( 14 ) for positioning, characterized in that the second satellites ( 10 ) in an earth orbit ( 16 ), which have a high eccentricity of at least about 0.5, a high inclination of at least 70 ° and an apogee over a polar region ( 18 ) and that over the other pole region outside the inner radiation zone ( 20 ) of the van Allen radiation belt, and the method comprises the steps of: receiving signals ( 12 ) from the second satellites ( 10 ) and benefits of second satellites ( 10 ) emitted signals ( 12 ) to improve the position determination. Method according to claim 1, characterized in that the earth orbit ( 16 ), on which the second satellites ( 10 ), an inclination between about 80 ° and about 100 °, in particular between about 80 ° and about 90 °, has. Method according to claim 1 or 2, characterized in that the apogee of the Earth orbit ( 16 ), on which the second satellites ( 10 ), about 20,000 to about 50,000 miles. Method according to Claim 1, 2 or 3, characterized in that the signals emitted by the second satellites ( 10 ) emitted signals ( 12 ) unlike that of the first satellites ( 24 ) and the receiving of these signals comprises switching the decoding to the decoding of these signals. Method according to one of the preceding claims, characterized in that that of the second satellite ( 10 ) emitted signals ( 12 ) on a different frequency than that of the first satellites ( 24 ) transmitted signals. Method according to one of claims 1 to 4, characterized in that the use of the second satellite ( 10 ) emitted signals ( 12 ) for improving the position determination depending on one or more of the following parameters: received field strength of the signals emitted by the second satellite; current position of receiving the signals emitted by the second satellites; Authorization to use signals emitted by second satellites. Usage system ( 14 ) for a satellite navigation system, in particular a mobile navigation device, for use with a method according to one of the preceding claims and for the reception of signals ( 12 ) of the second satellite ( 10 ) and the use of these signals to improve position determination in a polar region ( 18 ) is trained. Usage system according to claim 6, characterized in that it is further formed by the second satellite ( 10 ) emitted signals ( 12 ) to use for improving the position determination when the reception field strength of the signals emitted by the second satellite is greater than the reception field strength of the signals emitted by the first satellite, the current position of the utilization system is within the one polar region, and / or the utilization system has an authorization for Use of signals emitted by second satellites. Satellite ( 10 ), which is responsible for an Earth orbit ( 16 ) having a high eccentricity of at least about 0.5, a high inclination of at least 70 ° and an apogee over a polar region ( 18 ), which extends beyond the other pole region outside the inner radiation zone of the van Allen radiation belt, and which is further configured to receive signals ( 12 ) to improve the position determination by a utilization system. Satellite according to claim 8, characterized in that it comprises an adaptive antenna and is further adapted to measure the illumination angle with transmitted signals ( 12 ) under which the visible region of the earth appears from the satellite, by appropriate control of the adaptive antenna depending on its position over the one polar region ( 18 ).

Images