Patent Publication Number: US-10325506-B2

Title: Method for monitoring airspace

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a method for monitoring airspace, in particular to a method for identifying and locating aircraft in order to prevent collisions between aircraft. 
     Different systems are known for preventing collisions between manned aircraft. Known systems of this kind generally provide an on-board electronics system, comprising a computer having a screen, a data communications device, a FLARM (FLight alARM) and/or ADS-B (Automatic Dependent Surveillance-Broadcast) receiver, a transponder, a GNSS (Global Navigation Satellite System) device and an electronic control unit for processing data, in the respective aircraft. An aircraft receives the flight data of another aircraft via this on-board electronics system. The data which is received by the on-board electronics system is processed and graphically displayed to the pilot on the screen of the computer. In this way, the pilot can decide which measures should be initiated in order to prevent a collision with the other aircraft. However, data interchange of this kind requires both aircraft to have the same communications technology, so that the respectively sent and received flight data can also be read and processed. 
     Furthermore, DE 10 2007 032 084 A1 discloses a collision and conflict prevention system for autonomous unmanned aircraft (UAV—Unmanned Aerial Vehicle), in which the system uses available on-board sensors in order to create an image of the surrounding airspace. In this way, the airspace is surveyed for potential conflicts and, if a problem is encountered, a search for possible avoidance measures is started, wherein the avoidance routes correspond, as far as possible, to the prescribed rules of the air. 
     The known conflict prevention systems are accordingly arranged in the respective aircraft as on-board electronics systems. An on-board electronics system of this kind comprising a conflict prevention system may be too heavy for relatively small and/or lightweight manned or unmanned aircraft on account of the weight. A further problem is that not all aircraft have standardized communications technology and a transmitter for sending data and a receiver for receiving data. Aircraft comprising different communication and location systems therefore have the problem that they may not be able to recognize or identify all aircraft. 
     SUMMARY OF THE INVENTION 
     It is therefore the object of the invention to provide a method for monitoring airspace which allows cross-system airspace monitoring. 
     This object is achieved by the subject matter of patent claim  1 . Preferred developments are specified in the dependent claims. 
     Therefore, a method for monitoring airspace is provided according to the invention, said method having a first control and detection system and a second control and detection system, wherein the first control and detection system has a first aircraft and a first control and detection unit, and the second control and detection system has a second aircraft and a second control and detection unit, characterized in that an airspace monitoring system which is different from the first control and detection unit and also from the second control and detection unit is provided, first data relating to the first aircraft is transmitted to the airspace monitoring system by the first control and detection unit, and data which is based on the first data is sent to the second control and detection unit by the airspace monitoring system, and the data is transmitted to the second aircraft by the second control and detection unit. 
     Therefore, an essential aspect of the invention is that the first data relating to the first aircraft is transmitted to the airspace monitoring system by the first control and detection unit, and data which is based on the first data is sent to the second control and detection unit by the airspace monitoring system. In this way, the first data is transmitted to the second aircraft by the first aircraft by means of the airspace monitoring system and the second control and detection unit. 
     The first aircraft and/or the second aircraft are/is an unmanned aircraft or a manned aircraft. Unmanned aircraft are preferably to be understood to be drones. Manned aircraft include both lightweight sports airplanes, gliders, parachutists and also relatively large passenger and cargo airplanes. 
     The first control and detection unit and/or the second control and detection unit are/is preferably a ground station which has a continuous connection with the first aircraft and, respectively, the second aircraft. 
     The first control and detection unit and/or the second control and detection unit are/is particularly preferably a secondary radar system comprising a secondary radar transmitter and a secondary radar receiver, wherein the secondary radar receiver receives data which is sent by the aircraft and the transmitter sends data to the aircraft. The first control and detection unit and/or the second control and detection unit are/is very particularly preferably a primary radar system comprising a tracking system and a transmitter, wherein the tracking system gathers data of the aircraft and the transmitter sends data to the aircraft. 
     The first data is preferably data about the flight speed, the position, the altitude, the climb and/or descent rate, the distance and also the flight direction of the respective first aircraft. The first data is preferably signals. The first data is particularly preferably data structures for describing the airspace, on the basis of which data structures a flight area can be reserved. The first data is very particularly preferably computer-readable data, wherein the first data of the first aircraft can have different file formats. The file formats of the first data are preferably data from the FLARM or the ADS-B. 
     A further preferred development of the invention provides that a time stamp and/or a tracking ID is added to the first data and/or to the data. The time stamp makes it possible to check that the first data and/or the data are up-to-date. The tracking ID ensures that the data which is sent by the airspace monitoring system can be unambiguously assigned to the first data which is transmitted to the airspace monitoring system even at a later time. A traceable data profile in the airspace monitoring system is ensured in this way. 
     The speed of the data transmission can be of central importance, in particular, in order to prevent a collision between the first aircraft and the second aircraft. Therefore, a preferred development of the invention provides that the transmission of the first data by the first control and detection unit to the airspace monitoring system and sending of the data, which is based on the first data, by the airspace monitoring system to the second control and detection unit are transmitted and, respectively, sent virtually in real time and therefore immediately, without planned delays. This creates the possibility of providing data about the first aircraft directly to a second aircraft, in order to spot a collision between the first aircraft and the second aircraft in good time and to prevent said collision. The data communication between the first control and detection unit and the airspace monitoring system and, respectively, the airspace monitoring system and the second control and detection unit is preferably based on a web-based communication technology. Rapid and direct data communication is made possible in this way. 
     A further preferred development of the invention provides that the first data which is transmitted to the airspace monitoring system and/or the data which is sent to the second control and detection unit by the airspace monitoring system is transformed in the airspace monitoring system. During transformation of the first data which is transmitted to the airspace monitoring system, the first data is transformed into a file format that allows the first data to be processed in the airspace monitoring system. By transformation of the data which is sent by the airspace monitoring system, the data can first be transformed into the original file format of the first data and/or into a file format which is different from the first data. If the data is transformed into a file format which is different from the first data, the data which is based on the first data can be sent to a second control and detection unit which is different from the first control and detection unit. In this way, the first data of the first aircraft can be transmitted to a second aircraft the airspace monitoring system and the second control and detection unit by means of the first control and detection unit in a cross-system manner. The second aircraft can therefore read the first data of the first aircraft without having to have the corresponding communications technology of the first aircraft for this purpose. In addition to a positive effect on the weight of the second aircraft, costs can therefore additionally be reduced since each second aircraft does not have to have technology for transforming the data. 
     In order that the first data which is transmitted to the airspace monitoring system and/or the data which is sent by the airspace monitoring system can still be inspected and traced at a later time, a further preferred development of the invention is that the first data which is transmitted to the airspace monitoring system and/or the data which is sent to the second control and detection unit by the airspace monitoring system is stored in the airspace monitoring system. In this way, the flight route of the first aircraft can be documented. If the first aircraft is an unmanned aircraft, the storage and documentation of the first data or data can additionally meet the legislative requirements in respect of maintaining a logbook. 
     According to a further preferred development of the invention, it is provided that the first aircraft is identified by the airspace monitoring system. In this way, the first data can be assigned to a specific first aircraft. To this end, the first aircraft preferably has a machine-readable identifier which, amongst other things, permits conclusions to be drawn about the operator of the first aircraft. The machine-readable identifier is particularly preferably a chip card which is integrated into the first aircraft, a SIM card or else a QR code. In conjunction with the storage of the first data, further requirements in respect of maintaining the logbook for the unmanned aircraft can additionally be met in this way since the first data can be allocated to the first aircraft. 
     Strict safety requirements are placed on the transmission of data in the aviation sector, so that said data is not misused by unauthorized persons. A preferred development of the invention therefore provides that the first data which is transmitted to the airspace monitoring system and/or the data which is sent to the second control and detection unit by the airspace monitoring system is encrypted. Misuse of the first data which is transmitted to the airspace monitoring system and/or of the data which is sent by the airspace monitoring system can be reduced in this way. 
     In order to increase safety when transmitting data in the aviation sector and in particular for legally secure assignment of the first data which is transmitted to the airspace monitoring system, an advantageous development of the invention is that the first data which is transmitted to the airspace monitoring system and/or the data which is sent to the second control and detection unit by the airspace monitoring system is digitally signed. It is possible to draw conclusions about the operator of the aircraft, and therefore legally secure assignment of the first data of the first aircraft, which first data is transmitted to the airspace monitoring system, is possible, in this way. The digital signature of the first data is preferably made with a private key of the operator of the first aircraft. The first data is particularly preferably digitally signed by the first control and detection unit in respect of the first aircraft. The first data is very particularly preferably signed by the airspace monitoring system with a private key which is assigned to the first aircraft. 
     An advantageous development of the invention provides that, after the signature, preferably the operator and/or device signature, is checked, the first data is signed by the airspace monitoring system with a private key which is assigned to the airspace monitoring system itself. A plurality of first data items are preferably combined for this purpose in order to allow efficient data processing. 
     In this connection, a preferred development of the invention provides that the digital signature is made using a private key which is introduced into the airspace monitoring system in a personal and/or device-related manner by a copy-protected, cryptographic token. The token preferably meets the requirements for the qualified digital signature. The personal signature is particularly preferably made by means of the electrical identification. 
     Furthermore, a further preferred development of the invention provides that, based on the first data, a region of the airspace on the flight route of the first aircraft in the airspace monitoring system is reserved for the first aircraft for a period of time. In this way, the airspace monitoring system contains data of the flight route of the first aircraft, wherein this data is transmitted to the second control and detection unit. In this way, the second aircraft is reserved by means of the region of the airspace which is reserved by the first aircraft, so that the second aircraft can change its flight route if a collision with the first aircraft is expected. A possible collision can therefore be spotted in good time. 
     In addition to the first data about the flight route of the first aircraft, data of fundamental or temporary no-fly zones can also be stored in the airspace monitoring system. The data of fundamental or temporarily no-fly zones can preferably be called up by means of an authorizing body which is connected to the airspace monitoring system such that they can communicate. A further preferred development of the invention provides that data of a no-fly zone is stored in the airspace monitoring system and the data of the no-fly zone is checked using the first data which is transmitted to the airspace monitoring system. When a risk of collision is ascertained, data is transmitted by the airspace monitoring system to the first aircraft in order to change its flight route. In addition to the data of the no-fly zone, data relating to the proximity of airports and/or data relating to inner-city areas and/or data relating to complying with particular regulatory conditions is preferably stored in the airspace monitoring system and can be called up by means of the authorizing body which is connected to the airspace monitoring system such that they can communicate. In this way, it is possible to check in advance whether the planned flight or the planned flight route corresponds to the respective statutory and/or safety requirements. 
     According to a further preferred development of the invention, it is provided that, based on the first data for the first aircraft, ascent permission for the first aircraft is applied for and obtained by means of the airspace monitoring system. First data of the first aircraft about the flight route is stored in the airspace monitoring system in this way. In the event of a positive reply and ascent permission, data which is based on the first data is transmitted to the second control and detection unit. This data is not transmitted directly to the second control and detection unit, but rather only at the relevant time, that is to say only from the time at which the first aircraft begins to ascend and therefore there may be a risk of collision with the second aircraft. 
     A further preferred development of the invention provides that the first aircraft is an unmanned aircraft and the unmanned aircraft has a continuous connection to the first control and detection unit and, when the continuous connection is interrupted, first data relating to the interruption in connection is transmitted to the airspace monitoring system by the first control and detection unit, and data is sent to the second control and detection system by the airspace monitoring system based on the first data relating to the interruption in connection. In this way, the second aircraft is informed about the interruption in connection between the unmanned aircraft and the first control and detection unit, so that the second aircraft can pay increased attention to the air traffic in order to be able to quickly react in the event of an expected collision. 
     A further preferred development of the invention provides that the first control and detection unit is a constituent part of the second control and detection unit and forms a combined control and detection unit, and the first data is detected and transmitted to the airspace monitoring system by the combined control and detection unit and, based on the first data, data is sent to the combined control and detection unit by the airspace monitoring system. The first control and detection unit preferably differs from the second control and detection unit. In this way, the combined control and detection unit is of cross-system design. 
     In this connection, a further preferred development of the invention provides that the airspace monitoring system is an integral constituent part of the combined control and detection system. The first control and detection unit, the second control and detection unit and the airspace monitoring system form an integral system in this way. 
     In order to identify a possible collision between the first aircraft and the second aircraft, a preferred development of the invention provides that second data relating to the second aircraft is transmitted to the airspace monitoring system by the second control and detection unit. The airspace monitoring system checks the first data of the first aircraft and the second data of the second aircraft for a conflict, in particular for a possible collision. When a risk of collision is identified, data is transmitted to the second control and detection system based on the first data and the second data. In this way, the second aircraft is informed about the identified risk of collision with the first aircraft and can change its flight route. Therefore, the second aircraft does not require any technology on board for the purpose of evaluating the first data of the first aircraft, this having a positive effect on the weight of the second aircraft. In addition, the costs of the aircraft can be reduced in this way since the airspace monitoring system evaluates the data and there is no need for technology to be arranged in the first aircraft or in the second aircraft in order to evaluate the flight data. 
     The second data, like the first data, is preferably data about the flight speed, the position, the altitude, the climb and/or descent rate, the distance and also the flight direction of the respective second aircraft, wherein the file format of the second data can differ from the file format of the first data. 
     In this connection, a further preferred development of the invention provides that data, which is based on the second data, is sent to the first control and detection unit by the airspace monitoring system. In this way, the first aircraft receives data about the second aircraft. In addition, in the event of a risk of collision between the first aircraft and the second aircraft being identified by the airspace monitoring system, both the first aircraft and also the second aircraft can in this way be informed about the identified risk of collision and can each change their flight route. 
     A further preferred development of the invention is that the first data and second data which is transmitted to the airspace monitoring system is combined in the airspace monitoring system. In this way, based on this combined data, data can be sent to the first control and detection unit and/or data can be sent to the second control and detection unit in order to prespecify or propose a new flight route to the first aircraft and/or to the second aircraft. 
     In principle, it should be noted that the second data can be processed in a corresponding manner to the first data in the airspace monitoring system. Therefore, the second data can likewise be stored, transformed, encrypted and/or digitally signed. Identification of the second aircraft by the airspace monitoring system is likewise possible. Furthermore, based on the second data, the airspace for the second aircraft can be reserved in the airspace monitoring system, or ascent permission for the second aircraft can be obtained by means of the airspace monitoring system. 
     According to a further preferred development of the invention, it is provided that the first control and detection system has a plurality of first aircraft and/or the second control and detection system has a plurality of second aircraft, and the first control and detection unit transmits a plurality of first items of data to the airspace monitoring system. In this way, a large number of first aircraft and, respectively, second aircraft can be connected to the first control and detection unit and, respectively, the second control and detection unit, such that they can communicate, by means of the respective first control and detection unit and, respectively, the second control and detection unit. 
     Finally, a preferred development of the invention provides that the method comprises a plurality of first control and detection systems and/or a plurality of second control and detection systems. In this way, the airspace can be monitored for a large number of first aircraft and/or second aircraft in a cross-system manner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in greater detail below on the basis of a preferred exemplary embodiment with reference to the drawing, in which: 
         FIG. 1  is a schematic illustration of a method for monitoring airspace, wherein data of a first aircraft is transmitted to a second aircraft, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 2  is a schematic illustration of the method for monitoring airspace, wherein first data of the first aircraft is checked for a collision using second data of the second aircraft in the airspace monitoring system, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 3  is a schematic illustration of the method for monitoring airspace, wherein data is sent to the first control and detection unit and to the second control and detection unit by the airspace monitoring system, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 4  shows a machine-readable identifier in the form of a QR code for identifying the first aircraft and, respectively, the second aircraft, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 5  is a schematic illustration of the method for airspace monitoring with a plurality of first aircraft and second aircraft, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 6  shows a method sequence for detecting first data and second data in the airspace monitoring system, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 7  shows a method sequence for sending data from the airspace monitoring system, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 8  shows a method for distributing data of the airspace monitoring system in the event of an unplanned interruption in connection between the first control and detection unit or the second control and detection unit and the airspace monitoring system, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 9  shows a method for registering, identifying and authenticating a first aircraft using the airspace monitoring system, in accordance with the preferred exemplary embodiment of the invention, 
         FIG. 10  shows a method for reserving a flight area, in accordance with the preferred exemplary embodiment of the invention, and 
         FIG. 11  shows a method for obtaining flight clearance from an authorizing body, in accordance with the preferred exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a method for monitoring airspace, having a first control and detection system  100 , a second control and detection system  200  and an airspace monitoring system  300 . 
     The first control and detection system  100  comprises a first aircraft  110  and a first control and detection unit  120 , wherein the first control and detection unit  120  is connected to the first aircraft  110  such that they can communicate. Similarly, the second control and detection system  200  comprises a second aircraft  210  and a second control and detection unit  220 , wherein the second control and detection unit  220  is connected to the second aircraft  210  such that they can communicate. The first control and detection system  100  and the second control and detection system  200  are connected to one another, such that they can communicate, by means of the airspace monitoring system  300 . To this end, the first control and detection unit  120  and the second control and detection unit  220  are preferably connected to the airspace monitoring system  300  by means of a web-based communications connection. 
     In the present case, the first aircraft  110  is preferably a manned aircraft and the second aircraft  210  is preferably an unmanned aircraft. In addition, the first control and detection unit  120  is preferably a secondary radar system comprising a secondary radar transmitter and a secondary radar receiver, and the second control and detection unit  220  is preferably a ground station of an unmanned aircraft. Therefore, the first control and detection system  100  and the second control and detection system differ from one another. 
     For the purpose of monitoring airspace, the first control and detection unit  120  detects first data  130  of the first aircraft  110 , wherein this first data  130  is preferably data about the flight speed, the position, the altitude, the climb and/or descent rate, the distance and also the flight direction of the first aircraft  110 , and is preferably sent by means of the ADS-B. The first data is accordingly in the ADS-B file format. 
     The first data is transmitted to the airspace monitoring system  300  by the first control and detection unit. The first data  130  is transformed in the airspace monitoring system  300 . Based on this first data  130 , data  310  is sent to the second control and detection unit  220  and transmitted to the second aircraft  210  by the second control and detection unit  220 . In this way, the first data  130  of the first aircraft  110  can be made readable to the second aircraft  210  owing to the transformation of the first data  130  in the airspace monitoring system  300 . In this way, the second aircraft  210  can identify the flight route of the first aircraft  110  and change its own flight route if necessary. Therefore, the airspace can be monitored in a cross-system manner. 
     Communications technology between the first aircraft  110  and the first control and detection unit  120  is not required in addition to the communications technology between the second aircraft  210  and the second control and detection unit  220  in order to read the first data  130  of the first aircraft  110  in the second aircraft  210 . Therefore, no further communications technology is required in addition to the existing communications connection between the second aircraft  210  and the second control and detection unit  220  for the purpose of cross-system monitoring of the airspace, this having a positive effect on the weight of the second aircraft  210 . 
     Furthermore, it is provided that a time stamp is supplied to the first data  130  when said data is transmitted by the first control and detection unit  120 . In this way, it is possible to ensure that the first data  130  is up-to-date by virtue of comparing the time stamp with the actual time. 
     It is likewise provided that the first data  130  which is transmitted to the airspace monitoring system  300  and/or the data  310  which is sent by the airspace monitoring system  300  is stored in the airspace monitoring system  300 . In this way, the flight route of the first aircraft  110  can be documented. 
     In order to meet the strict safety requirements in respect of data transmission in the aviation sector, the first data  130  which is transmitted to the airspace monitoring system  300  and/or the data  310  which is sent to the second control and detection unit  220  by the airspace monitoring system  300  is encrypted. Misuse of the first data  130  which is transmitted to the airspace monitoring system  300  and/or of the data  310  which is sent by the airspace monitoring system  300  by unauthorized persons can be reduced in this way. 
     In order to be able to assign the first data  130  to a specific first aircraft  110 , the first aircraft  110  is identified by the airspace monitoring system  300 . To this end, the first aircraft  110  has a machine-readable identifier  140  which, amongst other things, permits conclusions to be drawn about the operator of the first aircraft  110 . The machine-readable identifier  140  can preferably be a chip card which is integrated into the first aircraft  110 , a SIM card or else a QR code. To this end, it is further provided that the first data  130  contains information of the machine-readable identifier  140 , so that the airspace monitoring system  300  can assign the first data  130  to the first aircraft  110 . 
     For the purpose of legally secure assignment of the first data  130  to the first aircraft  110  and, respectively, to the operator of the first aircraft  110 , it is additionally provided that the first data  110  which is transmitted to the airspace monitoring system  300  and/or the data  310  which is sent to the second control and detection unit  220  by the airspace monitoring system  300  is digitally signed. It is possible to draw conclusions about the operator of the aircraft  110 , and therefore legally secure assignment of the first data  130  of the first aircraft  110 , which first data is transmitted to the airspace monitoring system  300 , is possible, in this way. The digital signature of the first data  110  is preferably made with a private key of the operator of the first aircraft  110 . The first data  130  is particularly preferably digitally signed by the first control and detection unit  120  in respect of the first aircraft  110 . The first data is very particularly preferably signed by the airspace monitoring system with a private key which is assigned to the first aircraft. In this case, it is preferably provided that, after the signature is checked, the first data  130  is signed by the airspace monitoring system  300  with a private key which is assigned to the airspace monitoring system  300 . A plurality of first data items  130  are combined for this purpose in order to allow efficient data processing. 
     The present example is not restricted only to the case of the first aircraft  110  being a manned aircraft and the second aircraft  210  being an unmanned aircraft. It is likewise possible for the first aircraft  110  to be an unmanned aircraft and the second aircraft  210  to be a manned aircraft, or for the first aircraft  110  to be an unmanned aircraft and the second aircraft  210  to be an unmanned aircraft. 
     If the first aircraft  110  is an unmanned aircraft and the first control and detection unit  120  is a ground station, and the second aircraft is a manned aircraft and the second control and detection unit  220  is a secondary radar system, comprising a secondary radar transmitter and a secondary radar receiver, the first data  130  of the first aircraft  110 , which data is preferably in the form of computer-readable data, is transmitted to the airspace monitoring system  300  by the ground station  120 . The first data  130  is transformed into data of the FLARM and/or ADS-B file format in the airspace monitoring system  300 . The airspace monitoring system  300  sends the transformed data  310 , which is based on the first data  130 , to the second control and detection unit  220 . The second control and detection unit  220  transmits the data  310  to the second aircraft in the FLARM and/or ADS-B file format. The second aircraft can therefore identify the flight position and flight route of the first aircraft by means of the transformed data  310 . 
       FIG. 2  shows that, in addition to transmission of the first data  130  of the first aircraft  110  to the airspace monitoring system  300  by the first control and detection unit  120 , the second control and detection unit  220  transmits second data  230  to the airspace monitoring system  300 . 
     The first data  130  and/or the second data  230  are transformed, combined and checked for a collision within the airspace monitoring system. Based on the first data  130  and the second data  230 , data  310  is transmitted to the second control and detection unit  220  and forwarded to the second aircraft  210  by the second control and detection unit  220 . Evaluation and checking of the first data  130  and the second data  230  takes place in the airspace monitoring system  300 . Therefore, the second aircraft  210  does not require any technology on board in order to evaluate the first data  130  of the first aircraft  110 , this having a positive effect on the weight of the second aircraft. 
       FIG. 3  shows that data  310  is sent to the second control and detection unit  220  by the airspace monitoring system  300 , and data  310  is sent to the first control and detection unit  120 . 
     The first data  130  and second data  230  which is transmitted to the airspace monitoring system  300  is transformed in the airspace and checked for a collision. Based on the checking of the first data  130  and the second data  230 , data  310  is sent to the first control and detection unit  120  and to the second control and detection unit  220  by the airspace monitoring system  300 . In this way, the first aircraft  110  is informed about the position and flight route of the second aircraft  210  and the second aircraft  210  is informed about the position and flight route of the first aircraft  110  in a cross-system manner. In the event of a collision between the first aircraft  110  and the second aircraft  210  being identified, both the first aircraft  110  and also the second aircraft  210  can change their flight route. Since checking for a collision between the first aircraft  110  and the second aircraft is performed in the airspace over system  300 , neither the first aircraft  110  nor the second aircraft  210  requires the communications technology of the respective other aircraft. 
       FIG. 4  shows the machine-readable identifier  140  in the form of a QR code. In addition to a two-dimensional barcode  150 , the machine-readable identifier  140  additionally has an alphanumeric component  160  which provides information about the type of aircraft, contains an indication of origin relating to the country of registration, and has a character string for unambiguous identification. 
       FIG. 5  shows a method for monitoring airspace, having a plurality of first aircraft  110  and a plurality of second aircraft  210 . In the present case, the first aircraft  110  are unmanned aircraft and the second aircraft  210  are manned aircraft. 
     The unmanned aircraft are connected to the first control and detection unit  120 , which is in the form of a ground station, such that they can communicate. The ground station is, in turn, connected to the air monitoring system  300  such that they can communicate. 
     Furthermore, the air monitoring system  300  is connected to the second control and detection unit  220  such that they can communicate, wherein the second control and detection unit  220  is in the form of a secondary radar transmitter  222  and secondary radar receiver  224  or in the form of a radar tracking system  226 . 
     First data  130  of the respective unmanned aircraft are transmitted to the air monitoring system  300  by means of the ground station. Second data  230  of the respective manned aircraft are received by means of the secondary radar receiver  224  and/or by means of the radar tracking system  226  and sent to the air monitoring system  300 , wherein the second data  230  are transmitted in the FLARM and/or ADS-B format. 
     The first data  130  and second data  230  are transformed, stored and checked for a collision in the airspace monitoring system  300 . Based on this collision check, data  310  is transmitted to the unmanned aircraft by means of the ground station and to the manned aircraft, preferably in the FLARM and/or ADS-B format, by means of the secondary radar transmitter  222 . 
     If a risk of collision has been spotted, the data  310 , in particular the flight data of the unmanned aircraft, is changed in such a way that the flight route of said unmanned aircraft is changed in order to prevent the identified risk of collision. 
     The airspace monitoring system  300  is additionally connected to an air traffic control center  400  such that they can communicate, in order to transmit the data  310  to the air traffic control center  400 . In this way, the airspace can additionally be monitored by means of the air traffic control center  400 . 
     The airspace monitoring system  300  is additionally connected to an authorizing body  500  for authorizing ascent permissions and/or flight routes. In this way, ascent permission can be applied for and obtained before a flight based on the first data  130 , in particular data of a planned flight route, for the unmanned aircraft by means of the airspace monitoring system  300 . The first data  130  of the unmanned aircraft, in particular data of the planned flight route, is checked for any overlaps or conflicts with no-fly zones within the airspace monitoring system  300 . In addition, a check is made in respect of compliance with regulatory conditions. If all requirements are met, ascent permission is requested and/or granted by the airspace monitoring system  300 . 
       FIG. 6  shows a method for the detection of first data  130  and second data  230  by the airspace monitoring system  300 . 
     In a first method  600 , the first data  130  of the first aircraft, wherein the first aircraft is an unmanned aircraft, is transmitted to the airspace monitoring system  300  by means of the first control and detection unit which is in the form of a ground station. 
     In a second method  610 , the second data  230  of the second aircraft, wherein the second aircraft is a manned aircraft, is detected by a tracking system, preferably by a secondary radar receiver or an ADS-B receiver, and transmitted to the airspace monitoring system  300 . 
     A third method  620  provides that the second data of a manned aircraft is detected by a tracking network, preferably by an open glider network, and transmitted to the airspace monitoring system  300 . The open glider network preferably serves to detect second data of second aircraft which are equipped with FLARM, such as, preferably, paragliders, relatively small airplanes or helicopters. 
     The first data  130  which is transmitted to the airspace monitoring system by means of the first method  600  and the second data  230  which is transmitted to the airspace monitoring system by means of the second method  610  and/or third method  620  is identified in accordance with the respective aircraft in the airspace monitoring system, if necessary transformed, and stored in the airspace monitoring system  300 . In addition, the first data  130 , which is in the form of flight data, and the second data  230 , which is in the form of flight data, is checked for a collision. In this way, a possible collision between a first aircraft and a second aircraft can be identified on the basis of the flight data in the airspace monitoring system  300 . 
     A method for distributing the data which is stored in the airspace monitoring system and is based on the first data and the second data is shown in  FIG. 7 . According to said figure, the data which is stored in the airspace monitoring system and checked for the risk of a collision is transmitted to the first control and detection unit, which is in the form of a ground station, and sent to the unmanned aircraft, which is connected to the ground station such that they can communicate, by means of the ground station. In the event of a risk of the unmanned aircraft colliding with another unmanned or manned aircraft being identified, the data which is sent by the airspace monitoring system can contain information relating to a changed flight route, in order to prevent a collision in this way. Therefore, a new flight route is calculated by means of the airspace monitoring system, so that corresponding technology on board the unmanned aircraft is not required. 
     A further method provides that the data of the airspace monitoring system is transmitted to the second control and detection unit, which is in the form of a tracking system, and is forwarded to the manned aircraft by means of ADS-B and/or FLARM. Therefore, the manned aircraft are informed about the unmanned aircraft located in the airspace. Moreover, the data which is addressed to the manned aircraft can also contain information relating to a changed flight route, so that precautions for preventing a collision or a risk of collision can be taken in the manned aircraft. 
     In addition, a further method provides that, for control purposes, the data which is stored in the airspace monitoring system is transmitted to the air traffic control center for further use and control of said data. 
       FIG. 8  shows a method for distributing data of the airspace monitoring system in the event of an unplanned interruption in connection between a first control and detection unit, which is in the form of a ground station, and the airspace monitoring system or an unplanned interruption in connection between a second control and detection unit, which is in the form of a tracking system, and the airspace monitoring system. 
     If there is an interruption in connection between the airspace monitoring system and the ground station, wherein the ground station is connected to an unmanned aircraft (first aircraft), the expected flight route for the unmanned aircraft is ascertained or predicted in the airspace monitoring system based on the first data which was detected last. This data is provided in the airspace monitoring system together with the indication of the interruption in connection and sent to the manned aircraft by means of the second control and detection unit, so that said manned aircraft is made aware of the situation and can take any precautionary measures, such as, preferably, a changed flight route. In addition, this data is transmitted to the air traffic monitoring, so that the airspace can be monitored more closely. 
       FIG. 9  describes a method for registering, identifying and authenticating an unmanned aircraft (first aircraft) in the airspace monitoring system. 
     In a first step, the operator of the unmanned aircraft is registered in the airspace monitoring system. 
     Upon registration in the airspace monitoring system, the operator and the unmanned aircraft are provided, in a second step, with an airspace monitoring system identification number which can be unambiguously assigned. In this way, the unmanned aircraft can be unambiguously identified by the airspace monitoring system and the operator can be legally securely assigned. First data of the unmanned aircraft, which first data is received by the airspace monitoring system, can therefore be unambiguously assigned to the unmanned aircraft and to the operator. The airspace monitoring system identification number is preferably a machine readable identifier in the form of a QR code. 
     In a third step, the airspace monitoring system identification number is implemented in the unmanned aircraft, preferably on a SIM card or a chip card. The airspace monitoring system identification number is associated with the unmanned aircraft in this way. 
     All of the first data which is sent by the unmanned aircraft contains the airspace monitoring system identification number. In addition, the sent first data is digitally signed, so that the first data is introduced into the airspace monitoring system in a personal or device-related manner. 
       FIG. 10  shows a method for reserving a flight area or airspace, wherein the method comprises two methods. The first method exhibits a method for planning the flight route and defining the airspace in advance of departure, and the second method shows the method for reserving airspace immediately before departure. 
     The method relates to first aircraft which are in the form of unmanned aircraft. In addition, data of fundamental or temporary no-fly zones are stored in the airspace monitoring system or can be called up by means of the airspace monitoring system being connected to an authorizing body such that they can communicate. Moreover, data for complying with particular regulatory conditions is stored in the airspace monitoring system or can be called up by means of the authorizing body. 
     In the first method, sequence diagram on the left-hand side, the planned flight route for an unmanned aircraft is transmitted in the form of first data to the airspace monitoring system. In the airspace monitoring system, a preliminary check of the first data is carried out in respect of the data which is stored in the airspace monitoring system or can be called up by means of the airspace monitoring system for any no-fly zones or further regulatory requirements, such as, preferably, a distance which has to be maintained from certain areas or cities. 
     If the planned flight route of the unmanned aircraft meets all of the requirements, the airspace monitoring system identification number of the unmanned aircraft, type of the unmanned aircraft, departure and destination airport, flight route, duration of the planned flight and departure time and departure date are stored in the airspace monitoring system. 
     The stored data about the planned flight of the unmanned aircraft is transmitted to the authorizing body. 
     The method for reserving airspace before departure, sequence diagram on the right-hand side, proceeds substantially analogously to the above-described first method which describes the planning of the flight route before departure. 
     The request for flight permission for the planned flight made to the authorizing body is shown in FIG.  11 . The first data of the planned flight of the unmanned aircraft (first aircraft) is transmitted together with the airspace monitoring system identification number to the authorizing body with the request to grant flight permission. 
     The authorizing body checks the flight plan and issues acknowledgement in the form of a reply. The reply can be authorization of the flight or else rejection of flight authorization. If the authorizing body rejects the flight, the flight has to be re-planned. 
     LIST OF REFERENCE SYMBOLS 
       100  First control and monitoring system 
       110  First aircraft 
       120  First control and detection unit 
       130  First data 
       140  Machine-readable identifier 
       150  Two-dimensional barcode 
       160  Alphanumeric component 
       200  Second control and monitoring system 
       210  Second aircraft 
       220  Second control and detection unit 
       222  Secondary radar transmitter 
       224  Secondary radar receiver 
       226  Radar tracking system 
       230  Second data 
       300  Airspace monitoring system 
       310  Data 
       400  Air traffic control center 
       500  Authorizing body