Arrangement for observing a celestial body and method for scanning a celestial body

Abstract

Arrangement (38) for observing a celestial body comprising • an observation instrument (11) with ◯ an entrance opening (14) for admitting at least part of a celestial body image, ◯ an image generating device (18) for generating the celestial body image falling at least partially through the entrance opening (14), ◯ a spectrograph (20) for dividing light incident through the entrance opening (14) into spectral lines (23), ◯ at least one electronic image sensor (24) for detecting at least one of the spectral lines (23), • a compensation device (40) with at least one compensation axis (48, 56, 58) for compensating a relative movement between the celestial body image and the observation instrument (11) caused by the Earth's rotation, • at least one scanning axis (45, 47, 63) for generating a relative movement between the celestial body image and the observation instrument (11), wherein the at least one scanning axis (45, 47, 63) is arranged outside the observation instrument (11).

Description

The invention relates to an arrangement for observing a celestial body and to a method for scanning a celestial body.When observing celestial bodies, an image of the celestial body to be observed is generally generated on or in an observation instrument using a suitable device, for example a lens. In this case, there is the situation that this celestial body image moves with respect to the observation instrument located on the earth due to the rotation of the earth. This effect is undesirable in various observation situations, for example in the long-term observation of celestial bodies or the creation of long-term-exposed images of celestial bodies. To compensate for this effect, devices such as, for example, zolostates are known which make possible a tracking of the observation instrument corresponding to the rotation of the earth.For observing the sun, so-called spectro-Eliographs, among other things, are used as observation instruments. A spectrograph is used to generate a monochromatic image of the sun. In this case, the sunlight falls through the objective of a telescope onto an input slit of the spectrograph, so that a sun image is generated on the input slit. A small portion of the solar image passes through the input slit and is separated into its spectral lines, for example by means of a diffraction grating. By the isolated recording of one of the spectral lines by means of a photo plate, a monochromatic recording of the section of the solar image can be produced. In more recent designs of the spectrograph, the photo plate is frequently replaced by an electronic image sensor. This is known, for example, from U.S. Pat. No. 7,209,229 B2.In order to be able to image not only a portion of the sun image but the entire sun image, it is necessary to move the sun image uniformly over the entrance slit. Such movement of a celestial body image over the observation instrument is also referred to as "scanning". It is obviously immaterial whether the sky body image is moved with respect to the observation instrument or whether the observation instrument is moved with respect to the sky body image. However, a coordination of the movement speed of the sky body image with the photo plate or the electronic image sensor is essential. In order to simplify the coordination, a constant movement speed is preferably selected between the observation instrument and the sky body image.The simplest way to move the sky body image over the scope is to use the rotation of the earth and thus natural movement of the sky body image relative to a scope fixed on the earth. However, a disadvantage of this procedure is the relatively long transit time of the complete sky body image via the observation instrument.In order to be independent of the natural movement of the sky body image due to the earth rotation, different techniques were developed using the example of the spectrograph, in which a stationary sun image is first generated by means of a coelostat or by means of a heliostat, in order to then be able to generate a controllable relative movement between the entrance slit and the sun image. In the Meudon and Coimbra observation facilities, for example, the telescope objective arranged between the zolostate and the inlet gap is displaced. US 2011 / 0 051 121 A1 describes a displacement of the inlet gap.As further prior art, the documents US 2005 / 0 275 838 A1, DE 36 06 547 A1, DE 10 2019 103 297 A1 and DE 60 2005 000 530 T2 are mentioned.The disadvantages of the known arrangements and methods for moving the sky body image over the observation instrument are that they are very slow and / or the quality of the recording is unsatisfactory.The object of the invention is therefore to provide an arrangement for observing a celestial body which overcomes these disadvantages and is also simple to produce and operate and has a compact design.The invention is further based on the object of providing a method for moving a celestial body image with respect to an observation instrument, which overcomes the disadvantages of the methods known from the prior art and is simple to carry out.The object is achieved according to the invention by an arrangement for observing a celestial body having the features of patent claim 1 and a method for moving a celestial body image according to one of claims 15 to 17.Advantageous embodiments and developments of the invention are specified in the dependent claims.An arrangement according to the invention for observing a celestial body comprises an observation instrument having an inlet opening for the inlet of at least part of a celestial body image, an image generating device for generating the celestial body image falling at least partially through the inlet opening, a spectrograph for splitting light incident through the inlet opening into spectral lines, and at least one electronic image sensor for detecting at least one of the spectral lines.Preferably, the inlet opening is arranged in a planar element, wherein the planar element and the inlet opening lie in an inlet plane. The image forming apparatus is preferably an optical element having a focal point. The image forming apparatus is preferably arranged such that the focal point is arranged on the input plane. In the simplest case, the image forming device can be formed by a lens. Preferably, the image forming apparatus is constituted by a telescope. When aligning the observation instrument with a celestial body, an image of the celestial body on the input plane can thus be generated. If the celestial body image is arranged at least partially on the inlet opening, this part of the celestial body image can fall through the inlet opening.The inlet opening is preferably designed as an inlet gap. Particularly preferably, the entry gap is formed so narrow that only a part of the celestial body pattern can fall through it.The part of the sky body image that passes through the inlet opening can be broken down into its spectral lines by the spectrograph. For this purpose, the spectrograph can have in particular a diffraction grating. By detecting at least one of the spectral lines by the electronic image sensor, a monochrome recording of the part of the celestial body image falling through the input opening can be produced. By using an electronic image sensor, the spectral line to be recorded can be electronically selected and further processed in a simple manner.The observation instrument can be formed by a spectrograph and thus be configured to observe the sun.In addition, the arrangement according to the invention comprises a compensating device having at least one compensating axis for compensating a relative movement between the celestial body image and the observation instrument caused by the rotation of the earth. This makes it possible to observe the celestial body independently of the rotation of the earth.In addition, the arrangement according to the invention comprises at least one scanning axis for generating a relative movement between the celestial body image and the observation instrument. The celestial body image can thus be moved across the inlet opening independently of the rotation of the earth. The relative movement between the celestial body image and the observation instrument can thus be accelerated or decelerated as desired. In particular, if the inlet opening is formed in such a way that only a part of the celestial body image falls through the inlet opening, an overall image of the celestial body image can thus be produced from individual partial images. According to the invention, the at least one scanning axis is arranged outside the observation instrument.The compensation device and / or at least one of the at least one scanning axis is preferably arranged, preferably directly, on the observation instrument. As a result, the arrangement can be designed to be particularly compact. Preferably, the observation instrument is arranged, particularly preferably completely, in an instrument housing. Thus, transport to and installation at the site of use of the observation instrument can be simplified. The compensation device can also be arranged in the observation instrument. When the compensation device is arranged in the observation instrument, the compensation device is preferably arranged inside the instrument housing. Alternatively, the compensation device can be arranged outside the observation instrument.In one embodiment of the invention, the observation instrument is arranged rotatably about the at least one compensation axis and / or the at least one scanning axis. By the rotatable arrangement of the observation instrument about the at least one compensation axis, the relative movement between the celestial body image and the observation instrument caused by the earth rotation can be compensated by a movement of the observation instrument about the at least one compensation axis. By the rotatable arrangement of the observation instrument about the at least one scanning axis, a relative movement between the celestial body image and the observation instrument independent of the earth rotation can be generated by a movement of the observation instrument about the at least one scanning axis.The compensation device can comprise at least one reflection element which is arranged rotatably about the at least one compensation axis and / or the at least one scanning axis.By means of the at least one reflection element, the light emitted by the celestial body can be directed onto the observation instrument. By the rotatable arrangement of the at least one reflection element about the at least one compensation axis, the relative movement between the celestial body image and the observation instrument caused by the earth rotation can be compensated by a movement of the reflection element about the at least one compensation axis. By the rotatable arrangement of the at least one reflection element about the at least one scanning axis, a relative movement between the celestial body image and the observation instrument independent of the earth rotation can be generated by a movement of the observation instrument about the at least one scanning axis. The at least reflection element can comprise a mirror, for example. The compensating device can be designed in particular as a zoostat or heliostat.Preferably, the compensation device comprises a mounting with at least one mounting axis, wherein the at least one compensation axis is formed by at least one of the at least one mounting axis. Here and in the following, a stand-like device is referred to as mounting, which is suitable for carrying the observation instrument or the reflection element. If the observation instrument is arranged rotatably about the at least one compensation axis, the observation instrument is preferably arranged on the mounting. If the reflection element is arranged rotatably about the at least one compensation axis, the reflection element is preferably arranged on the mounting.In one embodiment of the invention, the mounting is designed as a parallactic mounting, wherein the at least one mounting axis comprises a declination axis and a rectification axis, and wherein the at least one compensation axis is formed by the rectification axis. This has the advantage that, in order to compensate for the relative movement between the celestial body image and the observation instrument caused by the earth rotation, only one movement about exactly one compensation axis, namely the rectification axis, is required. This makes it possible to simplify the structure and operation of the arrangement.The at least one scanning axis can be formed by the declination axis and / or the rectal ascension axis. As a result, the function of the at least one scanning axis can be integrated into the axes present on the mounting. If the at least one scanning axis comprises the rectification axis, the rectification axis can simultaneously be configured as a compensation axis and scanning axis. The speed of the compensating movement about the rectification axis can then be corrected by the speed of the scanning movement about the rectification axis. The extent to which the at least one scanning axis is formed by the declination axis and / or the rectification axis is preferably guided in particular by the orientation of the inlet gap. Preferably, the scanning movement is carried out in such a way that the celestial body image is guided transversely over the input gap. If the input gap is arranged, for example, orthogonally to the rectification, the scanning movement preferably takes place only about the rectification axis, so that the scanning axis is formed only by the rectification axis. If the input gap is arranged, for example, orthogonally to the declination, the scanning movement preferably takes place only about the declination axis, so that the scanning axis is formed only by the declination axis. If the orientation of the inlet gap does not correspond to either of these two examples, a correspondingly combined movement preferably takes place about the declination axis and the rectal ascension axis, such that the scanning axis is formed by the declination axis and / or the rectal ascension axis.In a further embodiment of the invention, the mounting is designed as an azimuthal mounting, wherein the at least one mounting axis comprises an elevation axis and an azimuth axis, and wherein the at least one compensation axis is formed by the elevation axis and the azimuth axis. With such a configuration of the mounting, a particularly simple structure of the mounting can be realized. With the elevation axis and the azimuth axis, such mounting typically has two balance axes.The at least one scanning axis can be formed by the elevation axis and / or the azimuth axis. To the extent to which the elevation axis and / or the azimuth axis are designed as a scanning axis, preferably depends in particular on the orientation of the input gap in accordance with the above explanations. If the at least one scanning axis comprises the elevation axis, the elevation axis can simultaneously be designed as a compensation axis and scanning axis. If the at least one scanning axis comprises the azimuth axis, the azimuth axis can simultaneously be designed as a compensation axis and scanning axis.In a further embodiment of the invention, the at least one scanning axis is formed by at least one additional axis different from the at least one mounting axis. As a result, the scanning axis can be specifically matched to the requirements of the scanning movement. Thus, the scanning movement can be carried out more accurately and in a manner decoupled from external influences. In this way, in particular the quality of the recording of the celestial body image can be improved. The observation instrument or the at least one reflection element can be mounted rotatably about the at least one additional axis with respect to the mounting. The rotation about the at least one additional axis can be effected by means of an additional actuator, which can have a higher precision than the at least one mounting axis.Preferably, the at least one scanning axis is correlated with the at least one electronic image sensor. The images produced by means of the image sensor are generally composed of a plurality of individual images of the parts of the celestial body image which respectively fall through the inlet opening. By correlating the at least one scanning axis with the at least one image sensor, the function of the at least one image sensor and movement about the at least one scanning axis can be coordinated with one another. In particular, with regard to the frequency at which the at least one image sensor produces the individual images and the sequence in which the individual images are combined to form an overall image of the celestial body image, the correlation is advantageous. In a simple case, the correlation can be embodied purely in terms of time. In this case, the starting time and / or the speed of the movement about the at least one scanning axis are known to the at least one electronic image sensor. The individual images can be subsequently assembled by a computer, in particular on the basis of these parameters. An electronic coupling of the movement about the at least one scanning axis and the at least one electronic image sensor is not required for this purpose. The at least one scanning axis and the at least one electronic image sensor are preferably electronically coupled to one another, particularly preferably by means of an electronic data processing unit.In a preferred embodiment of the invention, the at least one electronic image sensor is arranged such that it cannot be displaced with respect to the observation instrument. As a result, the observation instrument can be produced in a structurally simpler and more cost-effective manner. The at least one electronic image sensor preferably has a first dimension and a second dimension. The at least one image sensor may be arranged such that the at least one spectral line output by the spectrograph is aligned along the first dimension. In the case of a plurality of spectral lines output by the spectrograph, the spectral lines can be arranged parallel to one another in the direction of the second dimension. The first dimension of a detected spectral line can thus contain location information about the detected content. The second dimension of a detected spectral line may include color information about the detected content. The selection of one of the at least one spectral line to be detected, which falls at any point on the at least one image sensor, and the arrangement thereof in the overall image of the celestial body image can be effected electronically.The at least one electronic image sensor can be designed as a line sensor. As a result, the installation space required by the at least one electronic image sensor can be reduced and the observation instrument can be produced more cost-effectively. By using a line sensor, the computing effort in the generation of the recording of the celestial body image can also be reduced. The line sensor is preferably arranged parallel to the at least one spectral line output by the spectrograph in such a way that the at least one spectral line to be detected falls onto the line sensor. The line sensor is thus preferably arranged along the first dimension. The selection of the at least one spectral line to be detected can thus be made by arranging the line sensor along the second dimension. The additional acquisition of the color information is thus not necessary for generating a monochrome recording. A line sensor is thus sufficient for creating a monochromatic sky body image.Preferably, at least one of the following components has an electronic interface:• the image forming apparatus,• the spectrograph,• the at least one electronic image sensor,• the compensating device,• the at least one scanning axis.The electronic interface of the spectrograph is preferably arranged on the diffraction grating. The diffraction grating can be arranged, in particular for adjusting the wavelength, displaceably, in particular rotatably, with respect to the input slit or the collimation objective. Preferably, the wavelength of the diffraction grating can thus be adjusted in particular by means of the electronic interface of the spectrograph.The focusing of the observation instrument can be effected by changing the arrangement, in particular the distance, of the respective components to one another in at least one of the following component pairs:• Image forming apparatus - entrance slit,• collimating lens - input slit,• Camera lens - Image sensor.Preferably, the focusing can be adjusted by means of the electronic interface of at least one of the corresponding components. In particular for this, at least one of the following components can also have the electronic interface: input gap, collimation objective, camera objective.The electronic interface is preferably designed as an ASCOM interface. The ASCOM interface is a standardized software interface for astronomic equipment. As a result, the electronic communication and between the individual components can take place via a standardized software interface and can thus be facilitated. The operation of the arrangement with the aid of a central computer, which particularly preferably likewise has an ASCOM interface, is also thereby considerably simplified. It is particularly advantageous if the spectrograph has an ASCOM interface.A method according to the invention for moving a celestial body image with respect to an observation instrument using an arrangement described above, in which the observation instrument is arranged rotatably about the at least one compensation axis and the at least one scanning axis, comprises the following steps:• generating a celestial body image arranged in or on the observation instrument by means of the image generating device,• compensating the relative movement between the celestial body image and the observation instrument caused by the earth rotation by means of the compensating device by rotating the observation instrument about the at least one compensating axis,• Generation of a relative movement between the celestial body image and the observation instrument by rotating the observation instrument about the at least one scanning axis.These steps, like the steps of the methods described below, can also be carried out at least partially simultaneously.The celestial body image is preferably generated on the entrance plane of the observation instrument. If the at least one compensation axis and the at least one scanning axis comprise at least one common axis, the movement about the at least one compensation axis and the movement about the at least one scanning axis can preferably be superimposed on the at least one common axis, as described above.A further method according to the invention for moving a celestial body image with respect to an observation instrument using an arrangement described above, which comprises a reflection element, and in which the at least one reflection element is arranged rotatably about the at least one compensation axis and the at least one scanning axis, comprises the following steps:• generating a celestial body image arranged in or on the observation instrument by means of the image generating device,• compensating the relative movement between the celestial body image and the observation instrument caused by the rotation of the earth by means of the compensating device by rotating the at least one reflection element about the at least one compensating axis,• Generation of a relative movement between the celestial body image and the observation instrument by rotating the at least one reflection element about the at least one scanning axis.In this case, the at least one compensation axis and the at least one scanning axis typically comprise separate from one another in such a way that they do not comprise a common axis.A further method according to the invention for moving a celestial body image with respect to an observation instrument using an arrangement described above, which comprises a reflection element, and in which the at least one reflection element is arranged rotatably about the at least one compensation axis and the observation instrument is arranged rotatably about the at least one scanning axis, comprises the following steps:• generating a celestial body image arranged in or on the observation instrument by means of the image generating device,• compensating the relative movement between the celestial body image and the observation instrument caused by the rotation of the earth by means of the compensating device by rotating the at least one reflection element about the at least one compensating axis,• Generation of a relative movement between the celestial body image and the observation instrument by rotating the observation instrument about the at least one scanning axis.In this case, the compensating device is preferably formed by a mounting and the at least one scanning axis is formed by at least one additional axis different from the at least one mounting axis.In a development of the methods explained above, light incident through the input opening is broken down into spectral lines by means of the spectrograph and at least one of the spectral lines is detected by the electronic image sensor. In this case, the electronic image sensor preferably interacts electronically with the at least one scanning axis when detecting the at least one spectral line. In particular, detection parameters such as a detection frequency or an exposure time can be determined as a function of the movement speed about the at least one scanning axis. By the electronic interaction of the image sensor with the at least one scanning axis, the sequence or the respective position of the individual images in the total image can also be determined. The total recording can thus be generated from the individual recordings by means of an electronic data processing system. Monochromatic total images of the celestial body can thus be generated without a mechanical movement of the image sensor relative to the observation device being required.In a possible embodiment of the invention, different spectral lines of the part of the celestial body image falling through the input opening are detected. Thus, different monochrome images of the observed celestial body image can be generated simultaneously.Exemplary embodiments of the invention are explained on the basis of the following figures. It shows: FIG. 1 a shows a schematic representation of an observation instrument, FIG. 1 b shows a schematic illustration of an observation instrument with a line sensor, FIG. 2 is a schematic illustration of a first embodiment of a claimed arrangement, wherein the observation instrument is arranged on a parallactic mounting, FIG. 3 is a schematic illustration of a second embodiment of a claimed arrangement wherein the scope is mounted on an azimuthal mount, FIG. 4 is a schematic illustration of a third embodiment of a claimed arrangement, wherein a reflective element is arranged on a parallactic mounting, FIG. 5 is a schematic illustration of a fourth embodiment of a claimed arrangement, wherein the reflection element is arranged on an azimuthal mounting, FIG. 6 is a schematic illustration of a fifth exemplary embodiment of a claimed arrangement, wherein the reflection element is arranged on an azimuthal mounting and the observation instrument is arranged rotatably about an additional axis, FIG. 7 is a schematic illustration of a fifth embodiment of a claimed arrangement, wherein the observation instrument is mounted on a parallactic mounting and rotatable about an auxiliary axis.FIGS. 1a to 7 show various exemplary embodiments. The same reference numerals are used for identical and functionally identical parts. For the sake of clarity, not all reference numerals are used in each figure.FIG. 1 ashows a schematic representation of an observation instrument 11 embodied as a spectrograph 10, having an inlet opening 14 embodied as an inlet gap 12, an image generating device 18 embodied as a telescope 16 for generating a celestial body image, namely a sun image, falling at least partially through the inlet gap 12, a spectrograph 20 for separating light 22 incident through the inlet gap into spectral lines 23, and an electronic image sensor 24 for detecting at least one of the spectral lines.The inlet gap 12 is arranged in a planar element 26, wherein the planar element 26 and the inlet gap 12 lie in an inlet plane 28. When the observation instrument 11 is aligned with a celestial body such as the sun 30 (FIGS. 2 to 7 ), an image of the celestial body can thus be generated on the input plane 28. The entrance slit 12 is formed so narrow that only a part of the sun image can fall through it.The part of the sky body image that passes through the input gap can be broken down into its spectral lines 23 by the spectrograph 20. For this purpose, the spectrograph 20 has a diffraction grating 32. The spectrograph further comprises a collimating lens 34. As is also evident from FIG. 1a, the entrance slit 12 is also formed as a component of the spectrograph 20 in the embodiment shown.The spectral lines 23 reflected by the diffraction grating 32 are incident on the electronic image sensor 24 through a camera objective 36; by the electronic image sensor 24 detecting at least one of the spectral lines 23, a monochrome recording of the part of the solar image falling through the input slit 12 can be produced.In the exemplary embodiment shown in FIG. 1 a, the electronic image sensor 24 is arranged such that it cannot be displaced with respect to the spectrograph 10. The electronic image sensor 24 illustrated in FIG. 1 a has a first dimension 25 aand a second dimension 25 b. The image sensor 24 is arranged such that the at least one spectral line 23 output by the spectrograph 20 is aligned along the first dimension 25 a. In the case of a plurality of spectral lines 23 output by the spectrograph 20, the spectral lines 23 can be arranged parallel to one another in the direction of the second dimension 25 b. The first dimension 25 aof a detected spectral line 23 can thus contain location information about the detected content. The second dimension 25 bof a detected spectral line 23 may contain color information about the detected content.The illustration shown in FIG. 1 bdiffers from that shown in FIG. 1 ain that the electronic image sensor 24 is configured as a line sensor 24 a,whereby the installation space required by the electronic image sensor 24 is reduced. The line sensor 24 ais preferably arranged parallel to the at least one spectral line 23 output by the spectrograph 10 in such a way that the spectral line 23 to be detected falls onto the line sensor 24 b. The line sensor 24 ais thus arranged along the first dimension 25 a. The selection of the spectral line 23 to be detected can thus be made by the arrangement of the line sensor 24 aalong the second dimension 25 b.It is shown in FIGS. 2 to 7 that an arrangement 38 for observing a celestial body comprises, in addition to the observation instrument 11 which is schematically illustrated in FIG. 1 a, a compensating device 40 designed as a mounting 39 for compensating a relative movement between the celestial body image and the observation instrument 11 caused by the rotation of the earth.In the arrangement shown in Figure 2, the spectropheliograph 10 is mounted on a parallactic mounting 42 having a declination axis 44 and a rectal ascension axis 46. By moving the spectrograph 10 about the rectification axis 46, the relative movement between the spectrograph 10 and the sun image caused by the rotation of the earth can be compensated. The rectification axis 46 accordingly forms a compensation axis 48.In order that the sun image can be moved across the input gap 12 independently of the earth rotation, the arrangement 38 further comprises at least one scanning axis. This scanning movement is preferably carried out in such a way that the sun image is guided transversely over the input gap 12. Depending on the orientation of the inlet gap 12, the at least scanning axis is accordingly formed by the declination axis 44 and / or the rectification axis 46. Thus, the at least one scanning axis can comprise the rectification axis 46 as the first scanning axis 47 and / or the declination axis 44 as the second scanning axis 45. If the at least one scanning axis comprises the rectification axis 46, the rectification axis 46 can simultaneously be configured as a compensation axis 48 and a first scanning axis 47. The speed of the compensating movement about the rectification axis 46 can then be corrected by the speed of the scanning movement about the rectification axis 46.Due to the arrangement of the spectrograph 10 on the mounting 39, in the embodiment shown in FIG. 2, the observation instrument 11 is arranged rotatably about the compensation axis 48 and about the at least one scanning axis formed by the declination axis 44 and / or the rectification axis 46.The embodiment shown in FIG. 3 differs from that shown in FIG. 2 in that the mounting 39 is formed as an azimuthal mounting 50 having an elevation axis 52 and an azimuth axis 54. In order to compensate for the relative movement between the sun image and the spectrograph 10 caused by the earth rotation, the spectrograph is moved about the elevation axis 52 and about the azimuth axis 54, so that the azimuthal mounting 50 has a first compensation axis 56 with the elevation axis 52 and a second compensation axis 58 with the azimuth axis 54.The at least one scanning axis can comprise the elevation axis 52 as the first scanning axis 47 and / or the azimuth axis 54 as the second scanning axis 45. The extent to which the elevation axis 52 and / or the azimuth axis 54 are designed as a scanning axis is aligned according to the above exemplary embodiment, in particular, according to the alignment of the input gap 12. If the at least one scanning axis comprises the elevation axis 52, the elevation axis 52 is simultaneously designed as a first compensation axis 56 and a first scanning axis 47. Thus, both the first compensation axis 56 and the first scanning axis 47 are arranged directly on the observation instrument 11. If the at least one scanning axis comprises the azimuth axis 54, the azimuth axis 54 is simultaneously designed as a second compensation axis 56 and a second scanning axis 45.The compensation device 40 can be arranged spatially separated from the observation instrument 11. Corresponding exemplary embodiments are found in FIGS. 4 to 6, In these exemplary embodiments, the compensation device 40 comprises a reflection element 60. the light 22 emitted by the sun 30 can be directed onto the spectrograph 10 by means of the reflection element 60. The reflection member 60 is disposed on the mount 39. As a result, the reflection element 60 in each of the exemplary embodiments shown in FIGS. 4 to 6 is arranged rotatably about at least one compensation axis, such that the relative movement between the sun image and the spectrograph 10 caused by the rotation of the earth can be compensated by a movement of the reflection element 60. In particular in the exemplary embodiments shown in FIGS. 4 to 6, an instrument housing, not shown, of the observation instrument 11 can be designed in such a way that the compensating device 40 is arranged in the instrument housing.In the embodiment shown in FIG. 4, the mounting 39, on which the reflection element 60 is arranged, is formed as a parallel mounting 42. Accordingly, the compensation axis 48 is formed by the rectification axis 46. The at least one scanning axis can comprise, in particular depending on the orientation of the input gap 12, corresponding to the exemplary embodiment of FIG. 2, the rectification axis 46 as the first scanning axis 47 and / or the declination axis 44 as the second scanning axis 45. The spectrograph 10 is arranged immovably in FIG. 4.The embodiment shown in FIG. 5 differs from that of FIG. 4 in that the compensation device 40 is designed as an azimuthal mounting 50. According to the exemplary embodiment shown in FIG. 3, the first compensation axis 56 is formed by the elevation axis 52 and the second compensation axis 58 is formed by the azimuth axis 54. The at least one scanning axis can comprise, in particular depending on the orientation of the input slit 12, the elevation axis 52 as the first scanning axis 47 and / or the azimuth axis 54 as the second scanning axis 45. Otherwise, the exemplary embodiment shown in FIG. 5 is substantially identical to that shown in FIG. 4.In contrast to the arrangement 38 shown in FIG. 5, in the exemplary embodiment shown in FIG. 6, the at least one scanning axis is formed by a scanning axis 63 in the form of an additional axis 62, which scanning axis is different from the elevation axis 52 and the azimuth axis 54. The spectrograph 10 is arranged rotatably about the additional axis 62. The additional axis 62 and thus the scanning axis 63 is arranged directly on the observation instrument 11. The rotation about the additional axis 62 is effected by means of an additional actuator 64, which typically has a higher precision than the elevation axis 52 and the azimuth axis 54. Otherwise, the exemplary embodiment shown in FIG. 6 is substantially identical to that shown in FIG. 5.The mount 39 of the embodiment shown in Fig. 6 may be replaced by the parallel mount 42 of the embodiment shown in Fig. 4 in a corresponding manner instead of the azimuthal mount 50. In this case, the compensation axis 48 is formed by the rectification axis 46.As the exemplary embodiment shown in FIG. 7 shows, the spectrograph 10 can be mounted rotatably about the additional axis 62 relative to the mounting 39. Here, the mounting is constituted by the parallactic mounting 42, but may also be constituted by the azimuthal mounting 50 of the embodiment shown in FIG. 3. Also in the embodiment shown in FIG. 7, in which the spectrograph 10 is arranged on the mounting 39 so as to be rotatable about the additional axis 62, the torque required for rotation about the additional axis 62 is provided by the additional actuator 64.In the exemplary embodiments illustrated in FIGS. 2 to 7, the at least one scanning axis is correlated with the electronic image sensor 24. By correlating the at least one scanning axis with the image sensor 24, the function of the image sensor 24 and movement about the at least one scanning axis can be coordinated with one another.It should also be noted that the individual components of the arrangements 38 shown in FIGS. 2 to 7 can be combined differently with one another to form further exemplary embodiments of the arrangement 38. In particular, for example, the reflection element 60 can be arranged rotatably about the additional axis 62 and can be moved by means of the actuator 64.In each of the arrangements 38 shown in FIGS. 2, 3 and 7, the spectrograph 10 is arranged rotatably about the respective compensation axis 48, 56, 58 and the respective scanning axis 45, 47, 63. In order to move the sun image relative to the spectrograph 10, the telescope 16 is used to generate the image of the sun 30, i.e. the sun image, on the input plane 28 of the spectrograph 10. In order to compensate for the relative movement between the sun image and the spectrograph 10 caused by the earth rotation, the spectrograph 10 is rotated about the at least one compensation axis by means of the compensation device 40. In the exemplary embodiments shown in FIGS. 2 and 7, a rotation is accordingly carried out about the compensation axis 48 formed by the rectification axis 46. in the exemplary embodiment shown in FIG. 3, a rotation is accordingly carried out about the elevation axis 52 formed as the first compensation axis 56 and the azimuth axis 54 formed as the second compensation axis 58. For scanning the sun image, a relative movement between the sun image and the spectrograph 10 is simultaneously generated by rotating the spectrograph 10 about the first scan axis 47 and / or the second scan axis 45.If the compensation axis 48 of the exemplary embodiment shown in FIG. 2 or one of the compensation axes 56, 58 of the exemplary embodiment shown in FIG. 3 coincides with one of the scanning axes 45, 47 on a common axis, the movement about the corresponding compensation axis and the movement about the corresponding scanning axis can be superimposed on the common axis.In the exemplary embodiments shown in FIGS. 4 and 5, instead of the spectrograph 10, the reflection element 60 is arranged rotatably about the respective compensation axis 48, 56, 58 and the respective scanning axis 45, 47, 63. The method for moving the sun image relative to the spectrograph 10 differs in that the compensation of the relative movement between the sun image and the spectrograph 10 caused by the rotation of the earth by means of the compensation device 40 is effected by rotating the reflection element 60 about the compensation axis 48 (FIG. 4 ) or about the first compensation axis 56 and the second compensation axis 58. For scanning the sun image, a relative movement between the sun image and the spectrograph 10 is simultaneously generated by rotating the reflection element 60 about the first scanning axis 47 and / or the second scanning axis 45. Otherwise, the method is identical to that described above with reference to the exemplary embodiments of FIGS. 2, 3 and 7.In the exemplary embodiment shown in FIG. 6, in contrast to the exemplary embodiment shown in FIGS. 4 and 5, the scanning axis 63 is formed by the additional axis 62. The spectrograph 10 is rotatably mounted about the auxiliary axis 62. The method for moving the sun image relative to the spectrograph 10 differs in that the relative movement between the sun image and the spectrograph 10 takes place by rotating the spectrograph 10 about the scanning axis 63 designed as an additional axis 62. Otherwise, the method is identical to that described above with reference to the exemplary embodiments of FIGS. 4 and 5.In each of the above-described embodiments, at least one of the following components may have an electronic interface:• Image forming apparatus 18,• the spectrograph 20,• the at least one electronic image sensor 24,• the compensating device 40,• the at least one scanning axis 45, 47, 63.The electronic interface of the spectrograph 20 is preferably located on the diffraction grating 32. The diffraction grating 32 can be arranged, in particular for adjusting the wavelength, displaceably, in particular rotatably, with respect to the input slit 12 or the collimating lens 34. Preferably, the wavelength of the diffraction grating 32 can be adjusted by means of the electronic interface of the spectrograph 20.The focusing of the observation instrument 11 can be effected by changing the arrangement, in particular the distance, of the respective components to one another in at least one of the following component pairs:• Image forming apparatus 18 - entrance slit 12,• Collimating lens 34 - Input slit 12,• Camera lens 36 - Image sensor 24.Preferably, the focusing can be adjusted by means of the electronic interface of at least one of the corresponding components. In particular for this, at least one of the following components can also have the electronic interface: input gap 12, collimation lens 34, camera lens 36.List of reference characters10 Spectrograph 11 Observation instrument 12 Input slit 14 Input opening 16 Telescope 18 Image generating device 20 Spectrograph 22 Light 23 Spectral line 24 Image sensor 24 aLine sensor 25 aFirst dimension 25 bSecond dimension 26 Planar element 28 Input plane 30 Sun 32 Diffraction grating 34 Collimation objective 36 Camera objective 38 Arrangement 39 Mounting 40 Compensation device 42 Parallactic mounting 44 Declination axis 45 Second scanning axis 46 Right ascension axis 47 First scanning axis 48 Compensation axis 50 Azimuthal mounting 52 Elevation axis 54 Azimuth axis 56 First compensation axis 58 Second compensation axis 60 Reflection element 62 Additional axis 63 Scanning axis 64 Actuator

Claims

Arrangement (38) for observing a celestial body, comprising • an observation instrument (11) having ◯ an input opening (14) for the inlet of at least part of a celestial body image, ◯ an image generating device (18) for generating the celestial body image falling at least partially through the input opening (14), ◯ a spectrograph (20) for splitting light incident through the input opening (14) into spectral lines (23), ◯ at least one electronic image sensor (24) for detecting at least one of the spectral lines (23), • a compensating device (40) having at least one compensating axis (48, 56, 58) for compensating a relative movement between the celestial body image and the observation instrument (11) caused by the rotation of the earth, • at least one scanning axis (45, 47, 58), 63) for generating a relative movement between the celestial body image and the observation instrument (11), wherein the at least one scanning axis (45, 47, 63) is arranged outside the observation instrument (11).Arrangement according to Claim 1, characterized in that the compensating device (40) and / or at least one of the at least one scanning axis (45, 47, 63) is arranged on the observation instrument (11), preferably directly.Arrangement according to one of the preceding claims, characterized in that the observation instrument (11) is arranged rotatably about the at least one compensation axis (48, 56, 58) and / or the at least one scanning axis (45, 47, 63).Arrangement according to one of the preceding claims, characterized in that the compensating device (40) comprises at least one reflection element (60) which is arranged rotatably about the at least one compensating axis (48, 56, 58) and / or the at least one scanning axis (45, 47, 63).Arrangement according to one of the preceding claims, characterized in that the compensating device (40) comprises a mounting (39) with at least one mounting axis, wherein the at least one compensating axis (48, 56, 58) is formed by at least one of the at least one mounting axis.Arrangement according to claim 5, characterised in that the mounting (39) is formed as a parallactic mounting (42), wherein the at least one mounting axis comprises a declination axis (44) and a rectification axis (46), and wherein the at least one compensation axis (48) is formed by the rectification axis (46).Arrangement according to Claim 6, characterized in that the at least one scanning axis (45, 47) is formed by the declination axis (44) and / or the rectification axis (46).Arrangement according to Claim 5, characterized in that the mounting (39) is designed as an azimuthal mounting (50), wherein the at least one mounting axis comprises an elevation axis (52) and an azimuth axis (54), and wherein the at least one compensation axis (56, 58) is formed by the elevation axis (52) and the azimuth axis (54).Arrangement according to Claim 8, characterized in that the at least one scanning axis (45, 47) is formed by the elevation axis (52) and / or the azimuth axis (54).Arrangement according to one of Claims 5, 6 or 8, characterized in that the at least one scanning axis (63) is formed by at least one additional axis (62) which is different from the at least one mounting axis.Arrangement according to one of the preceding claims, characterized in that the at least one scanning axis (45, 47, 63) is correlated with the at least one electronic image sensor (24).Arrangement according to one of the preceding claims, characterized in that the electronic image sensor (24) is arranged such that it cannot be displaced with respect to the observation instrument (11).Arrangement according to one of the preceding claims, characterized in that the at least one electronic image sensor (24) is designed as a line sensor (24a).Arrangement according to one of the preceding claims, characterized in that at least one of the following components has an electronic interface: • the image generating device (18), • the spectrograph (20), • the at least one electronic image sensor (24), • the compensating device (40), • the at least one scanning axis (45, 47, 63).Method for moving a celestial body image with respect to an observation instrument (11) using an arrangement (38) according to one of Claims 1 to 14, wherein the observation instrument (11) is arranged rotatably about the at least one compensation axis (48, 56, 58) and the at least one scanning axis (45, 47, 63), having the following steps: • generating a celestial body image arranged in or on the observation instrument (11) by means of the image generating device (18), • compensating the relative movement between the celestial body image and the observation instrument (11) caused by the earth rotation by means of the compensating device (40) by rotating the observation instrument (11) about the at least one compensation axis (48, 56, 58), • generating a relative movement between the celestial body image and the observation instrument (11) by rotating the observation instrument (11) about the at least one scanning axis (45, 45, 47.63).Method for moving a celestial body image with respect to an observation instrument (11) using an arrangement (38) according to Claim 4 or according to Claim 4 and one of Claims 5 to 14, wherein the at least one reflection element (60) is arranged rotatably about the at least one compensation axis (48, 56, 58) and the at least one scanning axis (45, 47, 63), having the following steps: • generating a celestial body image arranged in or on the observation instrument (11) by means of the image generating device (18), • compensating the relative movement between the celestial body image and the observation instrument (11) caused by the earth rotation by means of the compensating device (48, 56, 58) by rotating the at least one reflection element (60) about the at least one compensation axis (48, 56, 58), • Generation of a relative movement between the celestial body image and the observation instrument (11) by rotating the at least one reflection element (60) about the at least one scanning axis (45, 47, 63).Method for moving a celestial body image with respect to an observation instrument (11) using an arrangement (38) according to claim 4 or according to claim 4 and one of claims 5 to 14, wherein the at least one reflection element (60) is arranged rotatably about the at least one compensation axis (48, 56, 58) and the observation instrument (11) is arranged rotatably about the at least one scanning axis (63), comprising the following steps: • generating a celestial body image arranged in or on the observation instrument (11) by means of the image generating device (18), • compensating the relative movement between the celestial body image and the observation instrument (11) caused by the earth rotation by means of the compensation device (40) by rotating the at least one reflection element (60) about the at least one compensation axis (48, 56, 58), • Generation of a relative movement between the celestial body image and the observation instrument (11) by rotating the observation instrument (11) about the at least one scanning axis (63).Method according to one of Claims 15 to 17, characterized in that light (22) incident through the input opening (14) is broken down into spectral lines (23) by means of the spectrograph (20), and at least one of the spectral lines (23) is detected by the electronic image sensor (24), wherein the electronic image sensor (24) cooperates electronically with the at least one scanning axis (45, 47, 63) when the at least one spectral line (23) is detected.

Images