WO2017103141A1

WO2017103141A1 - Method and device for determining wind speed

Info

Publication number: WO2017103141A1
Application number: PCT/EP2016/081476
Authority: WO
Inventors: Josef HÖFFNER; Timo P. VIEHL; Ronald EIXMANN
Original assignee: Leibniz-Institut Für Atmosphärenphysik E.V. An Der Universität Rostock
Priority date: 2015-12-18
Filing date: 2016-12-16
Publication date: 2017-06-22
Also published as: DE102015122201A1

Abstract

The invention relates to a device (1) and a method for determining wind speed in the atmosphere. In order to be able to also use low-intensity scattered radiation (S) to determine wind speed, according to the invention, the device (1) includes an optical wavelength filter (2) that has at least one filter edge, as well as at least one detector (3) for detecting the filtered scattered radiation (S).

Description

Method and device for determining the wind speed

The invention relates to a device for determining the wind speed in the atmosphere. Furthermore, the invention relates to a method for determining the

Wind velocity in the atmosphere, scattered by the laser radiation in the atmosphere and the scattered laser radiation as scattered radiation to determine the

Wind speed is filtered and examined.

Devices and methods for determining wind speed are well known. In known methods and devices, a portion of the scattered radiation is coupled out before the filtering as a reference from the scattered radiation and measured. In particular, when wind velocity in the stratosphere is to be determined or when only low intensity laser radiation is scattered to determine wind velocity in, for example, the troposphere, very little stray radiation returns to the apparatus to determine the wind velocity. The use of a portion of the scattered radiation as a reference is disadvantageous especially at low intensity of the scattered radiation, since the remaining part of the already low scattered radiation is difficult to measure. By the reference goes a part of the backscattered achievement for the

Wind measurement lost and only part of the Doppler effect is exploited, which requires a stronger signal.

The invention is therefore based on the object to provide an apparatus and a method for more sensitive determination of the wind speed in the atmosphere, wherein the wind speed can be readily determined even with scattered radiation with low intensity.

For the aforementioned device, the object is achieved in that the device comprises an optical wavelength filter for filtering backscattered from the atmosphere scattered radiation and a first detector for detecting the filtered scattered radiation, wherein the wavelength filter has two filter edges, or the device is an optical wavelength filter for Filtering backscattered from the atmosphere scattered radiation, as well as a first detector and a second detector for detecting the scattered radiation, wherein the wavelength filter has one and in particular only one filter edge, the wavelength filter is thus no bandpass, and is formed, portions of the scattered radiation with wavelengths only on one side of the filter edge to the first detector and portions of the scattered radiation with wavelengths only on the other side of the filter edge to the second detector. For the method mentioned in the introduction, the invention is achieved in that for determining the wind speed two scattered radiation generated by laser radiation of different spectrums whose maxima are spaced apart from one another

filtered filter portions are filtered out and filtered out portions of the scattered radiation and / or residual portions of the scattered radiation, or that to determine the wind speed, the scattered radiation filtered at a filter edge and a filtered out of the scattered radiation portion and a residual portion of the scattered radiation are examined.

Thus, neither with the device according to the invention nor with the method according to the invention is it necessary to decouple part of the scattered radiation before filtering in order to form the reference. Thus, essentially all of the scattered radiation can be filtered. Because the entire scattered radiation is filtered and no reference radiation is removed from the scattered radiation before the filtering, the intensity of the scattered radiation available before and after the filtering is comparatively higher than in known devices and methods. Due to the higher scattered radiation intensity and in particular the larger Doppler effect, the wind speed can be determined more easily and with a significantly reduced signal.

The solution according to the invention can be further improved by various configurations which are advantageous in each case and, if not stated otherwise, can be combined with one another as desired. These embodiments and the advantages associated with them are discussed below.

Thus, the device with the two-edge filter, ie the wavelength filter with the two filter edges, a laser device which emits laser radiation during operation for scattering in the atmosphere, the laser device emits in operation laser radiation with different spectra, and wherein the Maximum one of the spectra at the wavelength of one of the filter edges and the maximum of the other spectrum at the wavelength of the other filter edge. The laser device may include a laser capable of emitting radiation with the two spectra, or two different lasers.

This device is particularly simple to construct due to the use of only one wavelength filter. The wavelength filter may be a bandpass. The detector may be arranged downstream of the wavelength filter, so that the scattered light on the first

Wavelength filter and only after filtering on the wavelength filter hits the detector. The wavelength filter thus suppresses the remaining spectrum of the device incident light, wherein in addition to the scattered radiation further radiation, for example, daylight, can get into the device. For example, only radiation within the filter curve is passed through the wavelength filter, resulting in the determination of the

Wind speed is sufficient. A reference measurement in front of the filter, which additionally measures large amounts of disturbing daylight, is not needed. Since the device requires only one detector to which the filtered scattered radiation is supplied during operation of the device, light paths within the device need not be adapted to one another and

different detectors are compared. Consequently, the device is not only easy to build, but also easy to operate. Furthermore, the device reacts robustly to environmental influences, for example temperature fluctuations or vibrations.

The device with the two-edge filter may comprise a second detector, wherein the wavelength filter is formed, portions of the scattered radiation having wavelengths on only one side of the filter edges to the first detector and the proportion of scattered radiation with wavelengths only on the other side of the To guide filter edges to the second detector. For example, portions of the scattered radiation whose wavelengths lie on the same side of the filter edges, to the first, and portions of the scattered radiation whose

Wavelengths lie on the opposite side of the filter edges, are directed to the second detector. If the wavelength filter having two-filter edges is a bandpass filter, portions of the scattered radiation that lie either inside or outside the filter band can be conducted to the first detector. The other shares of

Scattered radiation can be directed to the second detector.

In this embodiment, the Doppler effect can be used four times to determine the wind speed. Advantage: The bigger the effect, the easier it is to measure. As a result, significantly less laser power is needed. Since the detectors need not be compared with each other here, the advantages of the

Embodiment of the device with the two-edge filter and the only one detector obtained. This embodiment of the device is particularly well suited to determine the wind speed at night. If the device is designed to separate the scattered radiation from background radiation caused by daylight, this embodiment of the device can determine the wind speed very accurately even at daylight and at very low intensity of the scattered radiation.

The device with the single-edge filter can have a laser device which emits laser radiation for scattering in the atmosphere during operation, the spectrum of the laser radiation having its maximum at the wavelength of the filter edge. A

Laser device, which is designed to emit laser radiation with only one spectrum, is simpler in construction and cheaper than the laser device of the device with the two-edge filter.

The wavelength filter can be formed, the polarization plane only of the

Stray radiation portion whose wavelength is only on one side of the at least one filter edge to rotate. Furthermore, the wavelength filter may comprise a polarizer, to which the scattered radiation after the rotation of the plane of polarization along a

Stray radiation path of the device is supplied. By the rotation of

Polarization level only of the scattered radiation component whose wavelength is only on one side of the at least one filter edge, the scattered radiation component whose wavelength is only on the other side at least one filter edge, remains untwisted, the polarizer, the scattered radiation component whose wavelength only on one side of the filter edge is separated from the remaining scattered radiation component whose polarization plane has not been rotated. The polarizer can be, for example, a polarizing beam splitter, that is to say a so-called polarizing beam splitter (PBS).

The device with the polarization plane rotating wavelength filter may comprise the first and second detectors, wherein the two detectors are connected downstream of the polarizer. The first detector can be the scattered radiation component whose

Polarization level was not rotated, fed. Consequently, the entire

Stray radiation that has passed through the wavelength filter, to determine the

Wind speed used, without it being necessary to couple a portion of the scattered radiation as a reference radiation from the backscattered scattered radiation before filtering.

The wavelength filter for rotation of the plane of polarization may comprise an atomic line filter, e.g. B. have a Faraday filter. Atomic line filters precisely rotate the polarization plane with respect to the position of the wavelength with respect to the filter edge so that the wind speed can be accurately measured.

The wavelength filter may comprise an etalon disposed along a stray radiation path of the device between the two detectors. Along the

Stray radiation path spreads the scattered radiation within the device. The device with the etalon can have only one or both detectors. If the device with the etalon has only one detector, the detector is preferably arranged along the scattered radiation path behind the etalon, so that only stray radiation that has passed through the etalon reaches the detector. Other radiation and especially daylight is prevented by the etalon from reaching the detector. The wavelength filter may use either recurring filter edges of the etalon as multiple filter edges. If the wavelength filter is an etalon, then the

Wavelength filter so at least one other filter upstream or downstream, which suppresses the sidebands of the etalon, since an etalon has a frequency comb with a periodically repeating filter curve.

In particular, to determine the wind speed during the day, two Etalons and an interference filter can be followed each other, which passes through the scattered light at least partially successively. The pre- or post-filters serve to separate or suppress daylight. However, this is only necessary during the day to separate daylight more effectively from stray light. If the wind speed at night, ie in the dark, be determined, it is sufficient if the wavelength filter has only one Etalon. The second etalon and the interference filter are then not necessary.

In addition to the one detector, the device may also comprise the second detector, to which radiation reflected back from the etalon is supplied. For example, the etalon allows stray radiation whose wavelength lies on one side of the filter edge of the etalon to pass this portion to the first detector. The portion of the scattered radiation whose wavelength lies only on the other side of the filter edge of the etalon is reflected and can be directed to the second detector, if this

is provided and / or turned on. The device can thus be designed to direct a portion of the scattered radiation transmitted to the first detector by the etalon and a portion of the scattered radiation reflected by the etalon to the second detector. The

Scatter radiation is therefore used completely to determine the wind speed.

In particular, when the device has the etalon, the device can a

Have polarizer, which reflects the scattered radiation along the Streustrahlungspfad to etalon. The polarizer may again be a polarizing beam splitter or a so-called polarizing beam splitter (PBS), which is designed to reflect the scattered radiation to the etalon. In particular, when the scattered radiation is generated by Rayleigh scattering, this is already sufficiently polarized. If the scattered radiation was caused by Mie scattering, the polarizer would still have to be preceded by an optical element that polarizes the Mie scattered radiation. Further, along the stray radiation path between the polarizer and the etalon, a retardation plate, such as a quarter-wave plate, may be disposed. The retardation plate rotates the polarization plane of the scattered radiation such that the scattered radiation reflected back from the etalon can pass through the polarizer along the scattered radiation path to the second detector. Polarizers and

Delay plates are common optical components, easy to handle and inexpensive. The device may have a determination unit that includes at least one

Detector of the device or with both detectors of the device signal transmitting is connected or can be connected. The determination unit may determine the wind speed based on the detector signals of the at least one detector, for example according to the method according to the invention.

To determine the wind speed, the intensities of the residual portions of the filtered scattered radiation can be subtracted from one another and the result of the subtraction can be divided by the sum of the intensities of the residual portions. Remaining portions of the scattered radiation are the portions of the scattered radiation that are left over after filtering. Alternatively, to determine the wind speed, the intensities of the filtered out portions of the filtered scattered radiation may be subtracted from one another and the result of the subtraction divided by the sum of the intensities of the filtered out portions.

To determine the residual or filtered portions, only one detector is necessary. Different residuals or filtered-out portions which are subtracted and added are, for example, proportions of scattered radiation produced by means of the laser beams having the different spectra. By subtracting the residual parts or the filtered-out portions from one another and then normalizing the result of the subtraction by dividing the accumulated portions, a measuring signal is generated which is filtered only at one filter edge and filtered out in comparison with known methods Scattered light is only conducted to a detector that is twice as large. Since the measurement signal is generated by the Doppler shift of the wavelength of the scattered radiation with respect to the laser radiation to be scattered, the double Doppler effect is thus obtained according to the method according to the invention.

If the device has two filter edges and two detectors, the normalized results of the subtraction of the residual parts from one another and the subtraction of the

filtered out portions, whereby not only the double but even the quadruple Doppler effect is used to determine the wind speed.

If the device has the wavelength filter with only one edge and two detectors, the intensity of the residual parts and the filtered-out portions of the filtered scattered radiation can be examined to determine the wind speed. In particular, the residual components and the filtered-out components can be subtracted from one another and the subtraction result can be subtracted from the sum of the residual components and the filtered-out components Normalization be shared, whereby here the double Doppler effect is used to determine the wind speed.

This embodiment has the advantage that it is very easy to perform, since you do not have to change the wavelength quickly with the laser device, which is very difficult. Technically, the method is therefore very easy to perform. It is only necessary to know the properties of the two light paths / detectors at all times. On the basis of the filtered scattered radiation, the temperature of the atmosphere in which the wind speed is to be determined can be determined before the determination of the wind speed. Alternatively, the temperature can be determined differently.

The invention is explained below by way of example with reference to embodiments with reference to the drawings. The different features of the embodiments can be combined independently of each other, as has already been explained in the individual advantageous embodiments.

Show it:

Figures 1 to 5 are schematic representations of different embodiments of the inventive device for determining the wind speed.

FIG. 6 shows a schematic representation of a wavelength filter of the device according to the invention,

Figures 7 and 8 are schematic representations of inventive method for determining the wind speed.

First of all, the structure and function of a device according to the invention for determining the wind speed are described with reference to the exemplary embodiment of the figure.

1 shows a first embodiment of a device 1 for determining the wind speed schematically with an optical wavelength filter 2 and a first detector 3. Further, FIG. 1 shows a laser device 4, which is separate from the

Device 1 or as part of the device 1 may be provided. In operation, the laser device 4 emits laser radiation L which is scattered in the atmosphere 5, in particular in order to be able to determine wind speeds in the atmosphere 5. Laser radiation L scattered as scattered radiation S receives the device 1. The wavelength filter 2 filters the scattered radiation S and passes the filtered scattered radiation to the first detector 3. For example, the wavelength filter 2 passes only filtered portions T1, T2 of the

Scattered radiation S or only residual portions R1, R2 of the scattered radiation S to the first

Detektor3.

For example, scattered radiation S scattered by the stratosphere for determining the wind speed in the stratosphere in the device 1 can be investigated. The laser radiation L is scattered in the stratosphere, at least in large part because of the Rayleigh scattering, so that the scattered radiation has a low intensity and a good intensity

Polarization has. If the troposphere for scattering the laser radiation L is used as part of the atmosphere 5 in order to measure wind speeds in the troposphere, the laser radiation L is additionally scattered due to Mie scattering.

The wavelength filter 2 has two different filter edges. The filter edges may be spaced far enough apart that wavelength distributions of scattered radiation S to be filtered at these filter edges are readily separable from one another. If the laser device 4 is part of the device 1, the laser device 4 can generate in operation laser radiations L which have different spectra. In particular, the maxima of these spectra are at the wavelengths of the filter edges.

Will scattered radiation S using the different spectra have

Laser radiation L, for example, generated sequentially, so the scattered

Stray radiation S at the different filter edges filtered to the detector 3 are passed.

FIG. 2 shows a further exemplary embodiment of the device 1 according to the invention. For elements which correspond in function and / or construction elements of the embodiment of Figure 1, the same reference numerals are used. For the sake of brevity, only the differences from the exemplary embodiment of FIG. 1 will be discussed below.

The device 1 is also shown in the embodiment of Figure 2 with the laser device 4 and the laser radiation L scattering atmosphere 5. Similarly, Figure 2 shows the scattered radiation S, which was generated by scattering of the laser radiation L in the atmosphere 5. The scattered radiation S is conducted to the wavelength filter 2. The wavelength filter 2 of the embodiment of FIG. 2 has only one filter edge whose spectral position preferably corresponds to the maximum of the spectrum of the scattered radiation L. Of the

Wavelength filter 2 passes a filtered-out portion T1 of the scattered radiation S to the first detector 3 and a remainder portion R1 to a second detector 6 of the apparatus 1. The sum of the intensities of the residual component R1 and the filtered-out component T1 essentially corresponds to the intensity of the scattered radiation S.

Figure 3 shows a further embodiment of the device 1 according to the invention schematically. For elements that correspond in function and / or construction elements of the previous embodiments, the same reference numerals are used. For the sake of brevity, the following is merely the differences from the previous ones

Embodiments received.

Also, the figure 3 shows the device 1 with the laser device 4 and the

Laser radiation L scattering atmosphere 5 and the scattered radiation S. The device 1 comprises the wavelength filter 2, wherein the wavelength filter 2 of the embodiment of Figure 3 is formed with two filter edges. Furthermore, the device 1 has the first detector 3 and the second detector 6. Since the wavelength filter 2 has two filter edges, the laser device 4 preferably emits laser beams L with different spectrums, the maxima of which are in each case at the wavelength of one of the filter edges.

For example, the wavelength filter 2 directs filtered-out portions T1, T2 to the first detector 3 and residual portions R1, R2 of the scattered radiation S to the second detector 6.

FIG. 4 shows a further exemplary embodiment of the device 1 according to the invention. For elements which correspond in function and / or construction elements, the embodiments of the previous figures, the same reference numerals are used. For the sake of brevity, only the differences from the previous exemplary embodiments will be discussed below.

The device 1, which in the figure 4 also with the laser device 4 and the

Atmosphere 5 and the laser radiation L and the scattered radiation S is shown, has an etalon 10 as a wavelength filter 2. The etalon 10 has a plurality of filter edges, which may be referred to as a filter comb. Emits the laser device 4

Laser radiation L with different spectra, so the maxima of these spectra can be on different filter edges of the etalon 10. However, if the laser device 4 emits laser radiation with only one spectrum, its maximum can be on one of the

Filter edges, and in particular on a selected filter edge of the etalon 10 are.

The etalon 10, the scattered radiation S is supplied through a polarizer 1 1, wherein the polarizer 1 1, the scattered radiation S, for example, toward the etalon 10 to reflect. Between the polarizer 1 1 and the etalon 10 is along a Stray radiation path P of the device 1, a delay plate 12 is arranged. The retardation plate 12 is, for example, a λ / 4 plate. The scattered radiation S passes through the retardation plate 12 and strikes the etalon 10. The etalon 10 passes a portion of the scattered radiation S whose wavelengths lie only on one side of one of the filter edges of the etalon 10 as a filtered-out component T1 to the first detector 3. The remaining portion R1 is reflected by the etalon 10. The retardation plate 12 changes the polarization of the remainder portion R1 such that the remainder portion R1 can be passed along the scattered radiation path P through the polarizer 11 to the second detector 6.

FIG. 5 shows a further exemplary embodiment of the device 1 according to the invention. For elements which correspond in function and / or construction elements, the embodiments of the previous figures, the same reference numerals are used. For the sake of brevity, only the differences from the previous exemplary embodiments will be discussed below.

As in the previous figures, FIG. 5 also shows the device 1 with the laser device 4 and the atmosphere 5 scattering the laser radiation L. The scattered laser radiation L is also directed to the device 1 as scattered radiation S in FIG. The wavelength filter 2 of the device 1 of the embodiment of FIG. 5 rotates the plane of polarization of the portion of the scattered radiation S whose wavelengths lie on one side of the filter edge. The polarization planes of other portions of the scattered radiation S whose wavelengths are on the other side of the filter edge are not rotated. The scattered radiation S can pass completely through the wavelength filter 2 and be split on a polarizer 20 downstream of the wavelength filter 2 into the filtered-out component T1 and the residual component R1. The residual portion R1 can be returned to the detector 6 and the filtered-out portion T1 to the detector 3. Due to the rotation of the polarization plane, the polarizer 20 separates the scattered radiation S into the two components R1, T1.

The wavelength filter 2 can also be preceded by the optional polarization element 13 in the exemplary embodiment of FIG. 5, so that the scattered radiation S is first polarized by the polarization element 13 and then the polarized scattered radiation S is directed to the wavelength filter 2. The wavelength filter 2 of the embodiment of FIG. 5 may be an atomic line filter 21, for example a Faraday filter. The stray radiation path P may be after the polarizer 20 in two

Scatter radiation path sections P1, P2 branch, each leading from the polarizer 20 to one of the detectors 3, 6. FIG. 6 shows schematically the function of the wavelength filter 2 with scattered radiation S.

On the abscissa axis 31 of the illustrated diagram 30, the wavelength λ is plotted in nanometers. The ordinate axis 32 of the diagram 30 shows the intensity of the scattered radiation S with any unit.

First, the function of the wavelength filter 2 with only one wavelength filter edge is described.

The filter edge 33 is at a first wavelength I. If the maximum of

Laser radiation L at the first wavelength I and the wind speed is 0 m / s, the scattered radiation SO has the spectrum shown as a solid line whose

Maximum is also at the first wavelength I. Is the wind speed greater than

0 m / s, the spectrum of the scattered radiation S is doppler shifted and provided with the reference symbol S1 as a dashed line. The maximum of the scattered radiation spectrum S1 is shown in FIG. 6 by way of example to the right of the first wavelength I.

The spectrum SO is arranged symmetrically to the first wavelength I. On both sides of the filter edge 33 existing portions of the spectrum SO are the same size. Is that lying

However, wind speed above 0 m / s, so the proportion of the spectrum S1 right wavelength I is greater than the proportion of the spectrum S1, the left of the first wavelength

1 lies. By way of example, the fraction to the left of the first wavelength I is the filtered-out component IT and the component to the right of the first wavelength I is the residual component R. If the wind speed increases, the maximum of the scattered radiation S moves farther away from the filter edge 33, so that the proportions R, T differ more and more from each other.

If the residual R and the filtered-out portion T are subtracted from each other when the wind speed is 0 m / s, the result is zero. However, if the scattered radiation is Doppler-shifted, the result is not equal to zero. Since the residual portion R and the filtered-out portion T are subtracted from each other, the Doppler shift has a double effect on the result, so that the wind speed can be determined with scattered radiation S of lower intensity than in a reference measurement.

However, the wavelength filter 2 may also have a second filter edge 34, which is arranged at a second wavelength II. The distance of the two wavelengths I, II corresponds to the filter width and the filter should be so wide that the part that lies within the filter curve does not protrude to the other side of the respective other filter edge. Preferably, the filter width is substantially equal to half the Doppler width of the signal.

If the wavelength filter 2 is a bandpass filter, the portions of the scattered radiation spectra SO, S3 present between the filter edges 33, 34 can form the filtered portions T. The portions S1 and S4 of the scattered radiation spectra lying outside the interval between the filter edges 33, 34 can be used as filtered-out portions R.

If the residual fraction R1 and the filtered-out component T1, as well as the residual component R2 and the filtered-out component T2, are each subtracted from one another when the wind speed is 0 m / s, the result is zero. However, if the scattered radiation is Doppler-shifted, the result is not equal to zero. Since the residual portion R1 and the filtered-out portion T1 and additionally the residual portion R2 and the filtered portion T2 are subtracted from each other, the Doppler shift affects four times on the result, so that the wind speed can be determined with scattered radiation S of a still low intensity.

Figure 7 shows a first embodiment of the method according to the invention for determining the wind speed schematically as a flow chart. For elements of the previous embodiments, which are used in the following to explain the method according to the invention, the same reference numerals are used.

The method 40 starts with a first method step 41, in which, for example, laser radiation L is emitted. In the following method step 42, the laser radiation L is scattered in the atmosphere 5. The laser radiation L scattered in the atmosphere 5 is received by the device 1 as scattered radiation S in method step 43.

In the following method step 44, the scattered radiation S is filtered. The intensity of the filtered-out portion T is measured in method step 45, wherein the

Process step 45 follows the process step 44. The method step 44 is followed by the method step 46, in which the intensity of a residual portion R of the scattered radiation S is measured. In method step 47, which follows the two method steps 45 and 46, the intensities of the two components R, T for determining the

Wind speed examined.

Optionally, prior to the method steps 45, 46, a method step 48 may first be carried out, in which the temperature of the atmosphere 5 in which the wind speed is measured should be determined. The temperature can be determined, for example, based on the sum of the shares T, R.

Figure 8 shows a further embodiment of the method according to the invention schematically as a flow chart. For elements of the previous embodiments, which are used in the following to explain the method according to the invention, the same reference numerals are used.

The method 50 of the embodiment of FIG. 8 starts with method step 51. In method step 51, laser radiation L whose spectral maximum is at a first wavelength I is emitted. The method steps 52, 53 essentially correspond to the method steps 42, 43.

In method step 54, the scattered radiation S is filtered, in the following

Process step 55, either the filtered-out portion T1 or the remaining portion R1 of the filtered scattered radiation S is measured.

In the following process step 56, laser radiation is emitted into the atmosphere 5 whose spectrum has its maximum at the second wavelength II. The method steps 57, 58 correspond again essentially to the method steps 42, 43.

In method step 59, the backscattered scattered radiation S is filtered as in method step 54, so that in the following method step 60, as in method step 55, the intensity of either the filtered-out component T2 or the remaining component R2 is determined.

In the subsequent process step 61, the velocity is determined on the basis of the filtered-out portions T1, T2 and / or the remaining portions R1, R2. Before the

Method step 61 can again be determined on the basis of the sum of the shares R, T, the temperature of the atmosphere 5, in which the wind speed is to be measured. Also in the embodiment of FIG. 8, first the temperature of the gas whose velocity is to be determined can be determined. reference numeral

contraption

2 wavelength filters

3 first detector

4 laser device

5 atmosphere

6 second detector

10 Etalon

1 1 polarizer

12 delay plate

20 polarizer

21 atomic line filter

30 diagram

31 axis of abscissa

32 ordinate axis

33, 34 Filter edge

40 procedures

41 emit laser radiation

42 Scatter laser radiation in the atmosphere

43 received scattered radiation

44 Filter stray radiation

45 Measure the intensity of the filtered portion

46 Measure the intensity of the remaining portion

47 Determine wind speed

48 Determine temperature

50 procedures

51 emit laser radiation of the first wavelength

52 Scatter laser radiation in the atmosphere

53 received scattered radiation

54 Filter scattered radiation

55 Measure the intensity of the filtered portion or the remaining portion

56 emit laser radiation of the second wavelength

57 Scatter laser radiation in the atmosphere

58 received scattered radiation

59 Filter scattered radiation

60 Measure the intensity of the filtered portion or residual portion 61 Determine the wind speed

I first wavelength

II second wavelength

L laser radiation

P scattered radiation path

P1, P2 scattered radiation path sections

T filtered out fraction

T1, T2 filtered-out portion of the filtered scattered radiation S scattered radiation

R residual share

SO, S1, S2, S3 filtered scattered radiation

R1, R2 Remaining portion of the filtered scattered radiation

Claims

claims

1 . Device (1) for determining the wind velocity in the atmosphere (5), characterized in that the device (1) comprises an optical wavelength filter (2) for filtering scattered radiation (S) scattered back from the atmosphere (5) and a first detector (3 ) for detecting the filtered scattered radiation (S), wherein the wavelength filter (2) has two

Filter edges (33, 34), or an optical wavelength filter (2) for filtering backscattered from the atmosphere (5) scattered radiation (S), and a first detector (3) and a second detector (6) for detecting the scattered radiation (S ), wherein the

Wavelength filter (2) has a filter edge (33) and is formed, portions (T1) of the scattered radiation (S) with wavelengths only on one side of the filter edge (33) to the first detector (3) and portions (R1) of the scattered radiation (S) with wavelengths only on the other side of the filter edge (33) to the second detector (6) to pass.

2. Device (1) according to claim 1, characterized in that the device (1) with the two-edge filter, a laser device (4) which emits in operation laser radiation (L) for scattering in the atmosphere (5) comprises wherein the laser device (4) in operation emits laser radiation (L) with different spectra, and wherein the maximum of one of the spectra at the wavelength (I) of one of the filter edges (33) and the maximum of the other spectrum at the wavelength (II) of the another filter edge (34).

3. Device (1) according to claim 1 or 2, characterized in that the

Device (1) with the two-edge filter having a second detector (6), wherein the wavelength filter (2) is formed, portions (T1, T2) of the scattered radiation (S) with wavelengths only on each side of the filter edges (33 34) to the first detector (3) and portions (R1, R2) of the scattered radiation (S) with wavelengths only on the other side of the filter edges (33, 34) to the second detector (6).

4. Device (1) according to claim 1, characterized in that the device with the single-edge filter has a laser device (4), which in operation

Laser radiation (L) for scattering at the atmosphere (5) emitted, wherein the spectrum of the laser radiation (L) has its maximum at the wavelength (I) of the filter edge (33).

5. Device (1) according to one of claims 1 to 4, characterized in that the wavelength filter (2) is formed, the plane of polarization only of

Scattered radiation component whose wavelength lies only on one side of the at least one filter edge (33), wherein the wavelength filter (2) has a polarizer (20) to which the scattered radiation (S) after rotation of the polarization plane along a scattered radiation path (P) the device (1) is supplied.

6. Device (1) according to claim 5, characterized in that the device (1) the first and the second detector (3, 6) and the polarizer (20), the two detectors (3, 6) are connected downstream, wherein the first detector (3) the scattered radiation component (T1), whose polarization plane has been rotated, and the second detector (6) the scattered radiation component (R1) whose polarization plane has not been rotated, is supplied.

7. Device (1) according to claim 5 or 6, characterized in that the

Wavelength filter (2) for rotating the polarization plane has an atomic line filter (21).

8. Device (1) according to one of claims 1 to 4, characterized in that the wavelength filter (2) has an etalon (10) along a

Stray radiation path (P) of the device (1) between the two detectors (3, 6) is arranged.

9. Device (1) according to claim 8, characterized in that the device

is formed, one of the etalon (10) transmitted portion (T1) of the scattered radiation (S) to the first detector (3) and a etalon (10) reflected portion (R1) of the scattered radiation (S) to the second detector (6) to pass ,

10. Device (1) according to claim 8 or 9, characterized in that the

Device comprising a polarizer (1 1) which reflects the scattered radiation (S) along the scattered radiation path (P) to the etalon (10), wherein along the

Stray radiation path (P) between the polarizer (1 1) and the etalon (10) a retardation plate (12) is arranged.

1 1. Method (40) for determining the wind speed in the atmosphere (5), in which laser radiation (L) is scattered in the atmosphere (5) and the scattered

Laser radiation (L) as scattered radiation (S) for determining the wind speed is filtered and examined, characterized in that for determining the wind speed two scattered radiation (SO, S1, S2, S3) generated at different filter edges (33, 34) with laser radiation (L) of different spectra whose maxima are spaced apart (44) and filtered-out portions (T) of the scattered radiation (SO, S3 ) and / or residual portions (R) of the scattered radiation (S1, S2), or the scattered radiation (S) at a filter edge (33) filtered and filtered out of the scattered radiation (S) portion (T) and a residual portion (R) of the scattered radiation (S) (45, 46, 54, 55, 60).

12. The method (40, 50) according to claim 1 1, characterized in that for determining the wind speed, the intensities of the residual portions (R1, R2) of the filtered scattered radiation (SO, S1, S2, S3) subtracted from each other and the result of the subtraction by the sum of the intensities of the residuals (R1, R2) are shared.

13. Method (40, 50) according to claim 11 or 12, characterized in that for determining the wind speed, the intensities of the filtered-out portions (T1, T2) of the filtered scattered radiation (SO, S1, S2, S3) are subtracted from one another and the result the subtraction by the sum of the intensities of the

filtered out portions (T1, T2) are shared.

14. Method (40, 50) according to claim 12 or 13, characterized in that for determining the wind speed the results of the calculations of

Claims 12 and 13 are averaged (47, 61).

15. Method (40, 50) according to claim 11, characterized in that for determining the wind speed, the intensities of the residual portions (R1, R2) and the filtered-out portions (T1, T2) of the filtered scattered radiation (SO, S1, S2, S3 ) to be examined.