Distance-compatible multi-node common-caliber communication and measurement optical system

Abstract

The invention discloses a distance-compatible multi-node common-caliber communication and measurement optical system. Relates to the technical field of space laser communication and measurement integration, in particular to the technical field of distance-compatible multi-node common-caliber communication and measurement optical systems. The problem that the laser communication and measurement integrated terminal cannot be verified at the same time is effectively solved, and the hidden danger that whether multifunctional common-path application is interfered or not is eliminated. The system is characterized by comprising a laser communication and time-frequency transmission bidirectional link, a laser communication and time-frequency transmission system, a reflective distance measurement and speed measurement system, a first communication and time-frequency transmission machine, a secondary mirror, a primary mirror, a multi-input and multi-output antenna, a common-caliber main antenna, a wavelength beam splitter, a second communication and time-frequency transmission machine, a reflective distance measurement and speed measurement machine and a corner reflector. After a laser communication and time-frequency transmission bidirectional link is established, a laser communication and time-frequency transmission system and a reflective distance measurement and speed measurement system are started.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated space laser communication and measurement, and in particular to the technical field of multi-node common-aperture communication and measurement optical systems with compatible distances. Background Art

[0002] The integration and networking of space laser communication, time-frequency transfer, ranging and speed measurement are the future development trends of satellite laser communication in my country. In order to realize long-distance, high-speed laser communication, ranging and speed measurement functions, laser communication payloads usually adopt a working system with multiple independent apertures. However, due to the small beam divergence angle of the laser communication terminal, it is difficult to eliminate the parallel error during ground testing and verification. Only a single function test can be carried out during ground testing, and it is impossible to verify all functions of the laser communication and measurement integrated terminal at the same time, leaving hidden dangers for interference in multi-functional common optical path applications. Based on the existing rotating parabola-based multi-transmit and multi-receive antenna, the present invention adds a common optical path angle reflector design, which can be compatible with long-distance transmission and short-distance testing and verification, and simultaneously carry out multi-node common-aperture laser communication, time-frequency transfer and reflective homologous ranging and speed measurement experiments, to achieve ground equivalent verification of the integrated satellite-borne laser communication terminal. Summary of the invention

[0003] In response to the above problems, the present invention discloses a multi-node common-aperture communication and measurement optical system with compatible distances, which relates to the technical field of integrated space laser communication and measurement. It effectively solves the problem of being unable to simultaneously verify laser communication and integrated measurement terminals, and eliminates the hidden danger of interference in multi-functional common optical path applications.

[0004] The multi-node common aperture communication and measurement optical system comprises:

[0005] Laser communication and time-frequency transfer bidirectional links, laser communication and time-frequency transfer systems, and reflective ranging and speed measurement systems;

[0006] After the laser communication and time-frequency transmission bidirectional link is established, the laser communication and time-frequency transmission system and the reflective ranging and speed measurement system are started;

[0007] The laser communication and time-frequency transmission bidirectional link comprises: a first communication and time-frequency transmission machine, a secondary mirror, a primary mirror, a multi-transmit and multi-receive antenna, a common aperture main antenna, a wavelength splitter, and a second communication and time-frequency transmission machine;

[0008] The laser communication and time-frequency transmission system comprises: a first communication and time-frequency transmission machine, a secondary mirror, a primary mirror, a multi-transmit and multi-receive antenna, a common aperture main antenna, a wavelength splitter, and a second communication and time-frequency transmission machine;

[0009] The reflective distance measurement and speed measurement system comprises: a reflective distance measurement and speed measurement machine, a common aperture main antenna, a wavelength splitter, a multi-transmitting and multi-receiving antenna and a corner reflector.

[0010] Furthermore, the laser communication and time-frequency transmission bidirectional link includes a sending laser communication and time-frequency transmission optical path and a receiving laser communication and time-frequency transmission optical path. In the sending laser communication and time-frequency transmission optical path, the first communication and time-frequency transmission machine emits laser, which passes through the primary mirror, the secondary mirror and the primary mirror in turn and is shot into the multi-transmitter and multi-receiver antenna. The multi-transmitter and multi-receiver antenna emits laser, which is transmitted through space to reach the co-aperture main antenna, and then is emitted into the second communication and time-frequency transmission machine through the wavelength splitter. In the receiving laser communication and time-frequency transmission optical path, the second communication and time-frequency transmission machine emits laser, which is transmitted through space to reach the co-aperture main antenna, and then is emitted into the first communication and time-frequency transmission machine after passing through the primary mirror, the secondary mirror and the primary mirror in turn.

[0011] Furthermore, the wavelength range of the first communication and the second communication and the time-frequency transmission machine is: 1549.31nm~1552.52nm, and the working mode is a opposed duplex; the main mirror aperture is ≥250nm; the multi-transmit and multi-receive antenna is composed of 6 reflectors, and the working range of a single reflector covers azimuth ±30°, pitch ±7.5°, the equivalent area of ​​two-by-two splicing is ≥85mm, and the surface is coated with a 1550nm band polarization-maintaining film; the common-aperture main antenna aperture is ≥85nm, and the center hole diameter is 17nm; the wavelength splitter is coated with a 1550nm±3nm anti-reflection film and a 1565nm anti-reflection film.

[0012] Furthermore, the laser communication and time frequency transmission system includes unidirectional laser communication and time frequency transmission and bidirectional laser communication and time frequency transmission; the implementation process of the unidirectional laser communication and time frequency transmission is specifically as follows: the first communication and time frequency transmission machine transmits laser through the sending laser communication and time frequency transmission optical path and enters the second communication and time frequency transmission machine to complete the unidirectional laser communication and time frequency transmission; the implementation process of the bidirectional laser communication and time frequency transmission is specifically as follows: after completing the unidirectional laser communication and time frequency transmission, the second communication and time frequency transmission machine re-transmits laser through the receiving laser communication and time frequency transmission optical path and enters the first communication and time frequency transmission machine to complete the bidirectional laser communication and time frequency transmission.

[0013] Furthermore, the reflective ranging and speed measuring system includes a laser emission optical path and a laser reflection optical path; in the laser emission optical path, the reflective ranging and speed measuring machine emits laser which is incident upon the common aperture main antenna via a wavelength splitter, the common aperture main antenna emits laser which is transmitted through space to reach a multi-transmitting and multi-receiving antenna, and then is incident upon a corner reflector via the multi-transmitting and multi-receiving antenna; in the laser reflection optical path, the corner reflector reflects laser which is emitted through the multi-transmitting and multi-receiving antenna, then is transmitted through space to reach the common aperture main antenna, and then is incident upon the reflective ranging and speed measuring machine via the wavelength splitter.

[0014] Furthermore, the operating wavelength of the reflective ranging and speed measuring machine is 1565nm, and the working mode is single-machine reflective; the field of view of the corner reflector is >3mrad, the diameter is 25.4mm, and it is evenly distributed between the multi-transmitter and multi-receiver antenna and the main mirror. The center position of the corner reflector is at 1 / 6 of the distance from the edge of the main mirror to its center when viewed from the top view of the system.

[0015] Furthermore, the working method of the optical system specifically includes:

[0016] S1. Establish a bidirectional link for laser communication and time-frequency transmission;

[0017] S2, send instructions to trigger laser communication and time-frequency transmission system and reflective ranging and speed measurement system.

[0018] Furthermore, the establishment of a bidirectional link of laser communication and time frequency transmission is specifically as follows: the first communication and time frequency transmission machine transmits laser through the transmitting laser communication and time frequency transmission optical path and enters the second communication and time frequency transmission machine, and the second communication and time frequency transmission machine then transmits laser through the receiving laser communication and time frequency transmission optical path and enters the first communication and time frequency transmission machine.

[0019] Furthermore, after being triggered, the working process of the laser communication and time frequency transmission system is specifically as follows: the first communication and time frequency transmission machine emits laser through the unidirectional laser communication and time frequency transmission and enters the second communication and time frequency transmission machine, and the second communication and time frequency transmission machine then emits laser through the bidirectional laser communication and time frequency transmission and enters the first communication and time frequency transmission machine.

[0020] Furthermore, after being triggered, the working process of the reflective ranging and speed measuring system is specifically as follows: the reflective ranging and speed measuring machine emits laser through the laser emission optical path and enters the corner reflector, and the corner reflector reflects the laser through the laser reflection optical path and enters the reflective ranging and speed measuring machine.

[0021] The beneficial effects of the present invention are:

[0022] The present invention can realize the simultaneous operation of short-range multi-node laser communication, time-frequency transmission, and reflective ranging and speed measurement in indoor environments, taking into account the optical axis consistency requirements of long-distance laser communication, time-frequency transmission, and reflective ranging and speed measurement, while minimizing the energy loss of the beam communication system. After the system is installed and adjusted, there is no need to physically adjust the components during indoor experiments, and the problem of setting up a folded optical path to solve the parallel difference in indoor experiments of previous multi-aperture systems is avoided. The system is not limited by the distance of laser transmission and the size of the beam divergence angle of the optical system. After the laser communication and time-frequency transmission bidirectional links are established, the optical path must meet the working conditions of reflective ranging and speed measurement, and can take into account the multi-functional integrated working system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a structural schematic diagram of the system described in an embodiment of the present invention;

[0024] Figure 2 Schematic diagram of the installation position of the corner reflector 9 according to the embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1,

[0027] This embodiment provides a multi-node common aperture communication and measurement optical system with compatible distances. The structure diagram of the system is shown in FIG. Figure 1 , characterized in that it includes:

[0028] Laser communication and time-frequency transfer bidirectional links, laser communication and time-frequency transfer systems, and reflective ranging and speed measurement systems;

[0029] After the laser communication and time-frequency transmission bidirectional link is established, the laser communication and time-frequency transmission system and the reflective ranging and speed measurement system are started;

[0030] The laser communication and time-frequency transmission bidirectional link comprises: a first communication and time-frequency transmission machine 1, a secondary mirror 2, a primary mirror 3, a multi-transmit and multi-receive antenna 4, a common aperture main antenna 5, a wavelength splitter 6, and a second communication and time-frequency transmission machine 7;

[0031] The laser communication and time-frequency transmission system comprises: a first communication and time-frequency transmission machine 1, a secondary mirror 2, a primary mirror 3, a multi-transmit and multi-receive antenna 4, a common aperture main antenna 5, a wavelength splitter 6, and a second communication and time-frequency transmission machine 7;

[0032] The reflective distance measurement and speed measurement system comprises: a reflective distance measurement and speed measurement machine 8 , a common aperture main antenna 5 , a wavelength splitter 6 , a multi-transmit and multi-receive antenna 4 and a corner reflector 9 .

[0033] The laser communication and time frequency transmission bidirectional link includes a sending laser communication and time frequency transmission optical path and a receiving laser communication and time frequency transmission optical path. In the sending laser communication and time frequency transmission optical path, after the first communication and time frequency transmission machine 1 is turned on, the 1550nm band laser with orthogonal polarization state is emitted through the aperture of the primary mirror 3 and injected into the secondary mirror 2. The working wavelength of the first communication and time frequency transmission machine 1 is in the range of 1549.31nm to 1552.52nm, the spatial light is emitted, the polarization state is two orthogonal linear polarization states, and the working system is a coherent mode. The aperture of the primary mirror 3 is ≥250mm. The secondary mirror 2 reflects the 1550nm band laser to the effective area of ​​the primary mirror 3. The secondary mirror 2 is a convex reflector, and its reflective surface has a reflectivity of 99.5% for the 1550nm wavelength and a size of 25.4mm. The primary mirror 3 reflects the 1550nm band laser to the multi-transmitting and multi-receiving antenna 4. The multi-transmitting and multi-receiving antenna 4 is composed of 6 reflectors, and the working range of a single reflector covers the azimuth ±3 0°, pitch ±7.5°, equivalent area of ​​two-by-two splicing ≥85mm, surface coated with 1550nm band polarization-maintaining film, which can keep the polarization of 1550nm band laser, the multi-transmitter and multi-receiver antenna 4 keeps the received 1550nm band laser polarization state orthogonal, and transmits to multiple nodes at the same time, and reaches the common-aperture main antenna 5 of a certain node through space transmission (any position within the working coverage range of the multi-transmitter and multi-receiver antenna 4, as long as a node is set, can receive the laser emitted by the multi-transmitter and multi-receiver antenna 4), and then reflects to the second communication and time-frequency transmission machine 7 through the wavelength splitter 6; the common-aperture main antenna 5 has an aperture of ≥85mm, a center hole diameter of 17mm, the wavelength splitter 6 is coated with 1550nm±3nm anti-reflection film, and the reflectivity is>95%, the working wavelength of the second communication and time-frequency transmission machine 7 is in the range of 1549.31nm~1552.52nm, the spatial light is emitted, the polarization state is two orthogonal linear polarization states, and the working system is a coherent mode.

[0034] In the receiving laser communication and time-frequency transmission optical path, the second communication and time-frequency transmission machine 7 emits a 1550nm band laser with an orthogonal polarization state, which is incident upon the wavelength splitter 6 into the common-aperture main antenna 5. The common-aperture main antenna 5 emits a 1550nm band laser, which is transmitted through space to reach the multi-transmitter and multi-receiver antenna 4. The multi-transmitter and multi-receiver antenna 4 maintains the orthogonal polarization state of the 1550nm band laser and reflects it into the effective area of ​​the primary mirror 3. The primary mirror 3 reflects the 1550nm band laser to the secondary mirror 2. The secondary mirror 2 reflects the 1550nm band laser through the aperture of the primary mirror 3 into the first communication and time-frequency transmission machine 1.

[0035] The laser communication and time frequency transmission system includes unidirectional laser communication and time frequency transmission and bidirectional laser communication and time frequency transmission; the implementation process of the unidirectional laser communication and time frequency transmission is specifically as follows: the first communication and time frequency transmission machine 1 emits a 1550nm band laser through the sending laser communication and time frequency transmission optical path and enters the second communication and time frequency transmission machine 7 to complete the unidirectional laser communication and time frequency transmission; the implementation process of the bidirectional laser communication and time frequency transmission is specifically as follows: after completing the unidirectional laser communication and time frequency transmission, the second communication and time frequency transmission machine 7 re-emits a 1550nm band laser through the receiving laser communication and time frequency transmission optical path and enters the first communication and time frequency transmission machine 1 to complete the bidirectional laser communication and time frequency transmission.

[0036] The reflective distance measurement and speed measurement system comprises a laser emission optical path and a laser reflection optical path; in the laser emission optical path, the reflective distance measurement and speed measurement machine 8 emits a 1565nm band laser through a wavelength beam splitter 6 and enters a common aperture main antenna 5; the working wavelength of the reflective distance measurement and speed measurement machine 8 is 1565nm, the spatial light is emitted, the polarization state is a linear polarization state, and the working system is a coherent mode; the beam splitter 6 is coated with a 1565nm anti-reflection film with a transmittance of >95%, and the common aperture main antenna 5 emits a 1565nm band laser, which is transmitted through space to reach the multi-transmitting and multi-receiving antenna 4, and then enters the corner reflector 9 through the multi-transmitting and multi-receiving antenna 4, such as Figure 2 As shown, the corner reflector 9 has a field of view of >3mrad and a diameter of 25.4mm, and is evenly distributed between the multi-transmitter and multi-receiver antenna 4 and the main mirror 3. The center position of the corner reflector 9 is at 1 / 6 of the distance from the edge of the main mirror 3 to its center from the top view of the system; in the laser reflection light path, the corner reflector 9 reflects the 1565nm band laser, which is emitted through the multi-transmitter and multi-receiver antenna 4, and then transmitted through space to reach the co-aperture main antenna 5, and then emitted into the reflective ranging and speed measuring machine 8 through the wavelength splitter 6.

[0037] Embodiment 2,

[0038] This embodiment provides a multi-node common aperture communication and measurement optical system with compatible distances, and the working method of the optical system specifically includes:

[0039] S1. Establish a bidirectional link for laser communication and time-frequency transmission.

[0040] The relevant operations of step S1 are introduced with a specific example:

[0041] The first communication and frequency transmission machine 1 emits a 1550nm band laser through the transmitting laser communication and frequency transmission optical path and enters the second communication and frequency transmission machine 7. The second communication and frequency transmission machine 7 then emits a 1550nm band laser through the receiving laser communication and frequency transmission optical path and enters the first communication and frequency transmission machine 1, thereby completing the establishment of a laser communication and frequency transmission bidirectional link.

[0042] S2, send instructions to trigger laser communication and time-frequency transmission system and reflective ranging and speed measurement system.

[0043] The relevant operations of step S2 are introduced with a specific example:

[0044] After the bidirectional link of laser communication and time frequency transmission is established, the operator sends a trigger command to trigger the laser communication and time frequency transmission system and the reflective ranging and speed measurement system; after triggering, the working process of the laser communication and time frequency transmission system is specifically as follows: the first communication and time frequency transmission machine 1 emits a 1550nm band laser through the unidirectional laser communication and time frequency transmission and enters the second communication and time frequency transmission machine 7, and the second communication and time frequency transmission machine 7 then emits a 1550nm band laser through the bidirectional laser communication and time frequency transmission and enters the first communication and time frequency transmission machine 1; the working process of the reflective ranging and speed measurement system is specifically as follows: the reflective ranging and speed measurement machine 8 emits a 1565nm band laser through the laser emission optical path and enters the corner reflector 9, and the corner reflector 9 reflects the 1565nm band laser through the laser reflection optical path and enters the reflective ranging and speed measurement machine 8.

Claims

1. A multi-node common aperture communication and measurement optical system with compatible distance, characterized in that: include: Laser communication and time-frequency transfer bidirectional link, laser communication and time-frequency transfer system and reflective ranging and speed measurement system; After the laser communication and time-frequency transmission bidirectional link is established, the laser communication and time-frequency transmission system and the reflective ranging and speed measurement system are started; The laser communication and time-frequency transmission bidirectional link comprises: a first communication and time-frequency transmission machine (1), a secondary mirror (2), a primary mirror (3), a multi-transmit and multi-receive antenna (4), a common aperture main antenna (5), a wavelength splitter (6) and a second communication and time-frequency transmission machine (7); The laser communication and time-frequency transmission system comprises: a first communication and time-frequency transmission machine (1), a secondary mirror (2), a primary mirror (3), a multi-transmit and multi-receive antenna (4), a common aperture main antenna (5), a wavelength splitter (6) and a second communication and time-frequency transmission machine (7); The reflective distance measurement and speed measurement system comprises: a reflective distance measurement and speed measurement machine (8), a common aperture main antenna (5), a wavelength splitter (6), a multi-transmitting and multi-receiving antenna (4) and a corner reflector (9).

2. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 1, characterized in that: The laser communication and time-frequency transmission bidirectional link comprises a sending laser communication and time-frequency transmission optical path and a receiving laser communication and time-frequency transmission optical path. In the sending laser communication and time-frequency transmission optical path, the first communication and time-frequency transmission machine (1) emits laser light which passes through the primary mirror (3), the secondary mirror (2) and the primary mirror (3) in sequence and is incident on the multi-transmitting and multi-receiving antenna (4). The multi-transmitting and multi-receiving antenna (4) emits laser light which is transmitted through space to the common aperture main antenna (5) and then is incident on the second communication and time-frequency transmission machine (7) through the wavelength splitter (6). In the receiving laser communication and time-frequency transmission optical path, the second communication and time-frequency transmission machine (7) emits laser light which passes through the wavelength splitter (6) and is incident on the common aperture main antenna (5). The common aperture main antenna (5) emits laser light which is transmitted through space to the multi-transmitting and multi-receiving antenna (4) and then is incident on the first communication and time-frequency transmission machine (1) after passing through the primary mirror (3), the secondary mirror (2) and the primary mirror (3) in sequence.

3. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 2, characterized in that: The wavelength range of the first communication and time-frequency transmission machine (1) and the second communication and time-frequency transmission machine (7) is 1549.31nm to 1552.52nm, and the working mode is a dual-beam duplex; the aperture of the main mirror (3) is ≥250nm; the multi-transmit and multi-receive antenna (4) is composed of 6 reflectors, the working range of a single reflector covers azimuth ±30°, pitch ±7.5°, the equivalent area of ​​two-by-two splicing is ≥85mm, and the surface is coated with a 1550nm band polarization-maintaining film; the aperture of the common aperture main antenna (5) is ≥85nm, and the diameter of the central hole is 17nm; the wavelength splitter (6) is coated with a 1550nm±3nm anti-reflection film and a 1565nm anti-reflection film.

4. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 3, characterized in that: The laser communication and time frequency transmission system comprises unidirectional laser communication and time frequency transmission and bidirectional laser communication and time frequency transmission; the implementation process of the unidirectional laser communication and time frequency transmission is specifically as follows: the first communication and time frequency transmission machine (1) emits laser light through the sending laser communication and time frequency transmission optical path and injects it into the second communication and time frequency transmission machine (7), thereby completing the unidirectional laser communication and time frequency transmission; the implementation process of the bidirectional laser communication and time frequency transmission is specifically as follows: after completing the unidirectional laser communication and time frequency transmission, the second communication and time frequency transmission machine (7) emits laser light again through the receiving laser communication and time frequency transmission optical path and injects it into the first communication and time frequency transmission machine (1), thereby completing the bidirectional laser communication and time frequency transmission.

5. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 3, characterized in that: The reflective distance measurement and speed measurement system comprises a laser emission optical path and a laser reflection optical path. In the laser emission optical path, a reflective distance measurement and speed measurement machine (8) emits laser light and enters a common aperture main antenna (5) through a wavelength splitter (6). The common aperture main antenna (5) emits laser light, which is transmitted through space to reach a multi-transmitting and multi-receiving antenna (4), and then enters a corner reflector (9) through the multi-transmitting and multi-receiving antenna (4). In the laser reflection optical path, the corner reflector (9) reflects laser light and emits it through the multi-transmitting and multi-receiving antenna (4), which is then transmitted through space to reach the common aperture main antenna (5), and then enters the reflective distance measurement and speed measurement machine (8) through the wavelength splitter (6).

6. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 5, characterized in that: The reflective distance and speed measuring machine (8) has an operating wavelength of 1565 nm and a single-machine reflective operating mode; the corner reflector (9) has a field of view of >3 mrad and a diameter of 25.4 mm and is evenly distributed between the multi-transmit and multi-receive antenna (4) and the main mirror (3); the center position of the corner reflector (9) is located at 1 / 6 of the distance from the edge of the main mirror (3) to its center when viewed from a top view of the system.

7. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 5, characterized in that: The working method of the optical system specifically includes: S1. Establish a bidirectional link for laser communication and time-frequency transmission; S2, send instructions to trigger laser communication and time-frequency transmission system and reflective ranging and speed measurement system.

8. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 7, characterized in that: The establishment of the laser communication and time frequency transmission bidirectional link is specifically as follows: the first communication and time frequency transmission machine (1) emits laser light through the sending laser communication and time frequency transmission optical path and injects it into the second communication and time frequency transmission machine (7), and the second communication and time frequency transmission machine (7) then emits laser light through the receiving laser communication and time frequency transmission optical path and injects it into the first communication and time frequency transmission machine (1).

9. The multi-node common aperture communication and measurement optical system with compatible distance according to claim 7, characterized in that: After being triggered, the working process of the laser communication and time frequency transmission system is specifically as follows: the first communication and time frequency transmission machine (1) emits laser light and injects it into the second communication and time frequency transmission machine (7) through the one-way laser communication and time frequency transmission, and the second communication and time frequency transmission machine (7) then emits laser light and injects it into the first communication and time frequency transmission machine (1) through the two-way laser communication and time frequency transmission.

10. The multi-node common-aperture communication and measurement optical system with compatible distance according to claim 8, characterized in that: After being triggered, the working process of the reflective distance measurement and speed measurement system is specifically as follows: the reflective distance measurement and speed measurement machine (8) emits laser light through the laser emission optical path and enters the corner reflector (9), and the corner reflector (9) reflects laser light through the laser reflection optical path and enters the reflective distance measurement and speed measurement machine (8).

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