WO2007033644A1

WO2007033644A1 - Measuring arrangement for recording environmental parameters and operational parameters for a device working under vacuum conditions in space or the laboratory

Info

Publication number: WO2007033644A1
Application number: PCT/DE2006/001622
Authority: WO
Inventors: Gerhard Schmidtke
Original assignee: Fraunhofer-Gesellchaft Zur Förderung Der Angewandten Forschung E.V.
Priority date: 2005-09-22
Filing date: 2006-09-15
Publication date: 2007-03-29
Also published as: DE102005045463A1; DE102005045463B4

Abstract

The invention relates to a measuring arrangement for recording the charging of a satellite, the solar wind in space and extreme ultraviolet radiation, having three metallic electrodes (14, 18, 50). The first metallic electrode (50) is a hollow metal sphere enclosed by the second electrode in the form of an internal grid (14) and a further electrode in the form of an outer grid (18). The three electrodes are connected to voltage supplies which may be controlled. The changes in current occurring with voltage changes are recorded and processed in a control and analysis circuit for data output. Scintillation crystals and optical detectors may be placed within the metal sphere (50) in order to record additional particle and gamma radiation.

Description

Messaπordnunα to capture Umâebungsparametem and operating parameters for working under vacuum conditions in space or in the laboratory device

The invention relates to a measuring arrangement for detecting environmental parameters and operating parameters for a device working under vacuum in space or in the laboratory, in particular a spacecraft exposed to solar wind and extremely ultraviolet radiation and thereby electrically charged.

To increase the accuracy of satellite navigation data, it is necessary to detect a number of confounding factors in space and in satellite systems. The accuracy of navigation measurements using satellites depends largely on the calculation of the propagation of the signals on their way from the satellite to the receiver on Earth. It is determined by the integral column density of the ionospheric electrons and is subject to constant changes due to the continuously variable solar activity. These are predominantly determined by solar extreme ultraviolet radiation and to a smaller, but not negligible proportion of the solar wind.

Conventional measuring devices for measuring extreme ultraviolet radiation use rotatable optical grids or detector lines of many single detectors. These must be aligned with the help of Sonnenfolgern to the radiation source, which results in a considerable effort. In addition, surface effects on the optical gratings and detectors lead to unpredictable degradation, so that a change in Kalibrierparametem occurs continuously.

Based on this prior art, the present invention seeks to provide a device that it gestat- to measure and quantify space weather parameters for a variety of space missions.

This object is achieved in a measuring arrangement of the type mentioned above in that the missile comprises an insulating spacer on which as the first electrode, a first inner electrically conductive grid, which encloses an interior, and as a second electrode, a second outer grid, the the inner grid enclosing, are isolated from each other, wherein the inner grid and the outer grid can be acted upon with a predetermined grid potential and the current flowing to the missile current depending on the respective potential of the electrodes for obtaining data, in particular space weather data, evaluable.

In a preferred embodiment, the two grids enclose an electrically conductive hollow body as a third electrode, the potential of which is likewise adjustable to a previously determinable value. It is expedient if the grids and the electrically conductive hollow body are formed as three concentrically arranged electrodes having a substantially spherical shape. The grids are preferably each formed as a spherical double-layered grid of two mesh gratings with high optical transmission.

In one embodiment of the invention, it is provided that scintillation crystals are arranged in the interior of the spherical hollow body, the light of which can be detected by at least one optical detector.

The three electrodes of the measuring arrangement are connected via current measuring devices with their associated voltage sources for the provision of the predetermined potentials.

Advantageous embodiments of the invention and of methods for detecting extreme ultraviolet radiation, for detection the solar wind and to determine the electrical charge of a spacecraft emerge from the following description and the dependent claims.

Embodiments of the invention will be described in more detail with reference to the drawings. Show it:

1 shows a measuring arrangement with two grids for detecting the electrical charge of a satellite,

2 is an enlarged view of the two grids of the measuring arrangement of FIG. 1,

3 shows voltage and current characteristics of the electrodes of the measuring arrangement according to FIG. 1, FIG.

4 shows a measuring arrangement for detecting the solar wind,

Fig. 5 voltage and current waveforms of the electrodes of

Measuring arrangement according to FIG. 4,

6 shows a measuring arrangement for detecting and evaluating extreme ultraviolet radiation,

7 voltage and current waveforms of the electrodes of the measuring arrangement according to FIG. 6, FIG.

8 shows a measuring arrangement which contains all the components of the measuring arrangements according to FIGS. 1, 4 and 6.

1 shows a first exemplary embodiment of a measuring arrangement for detecting operating parameters for a device working under vacuum in space or in the laboratory. If this device is a spacecraft, in particular a satellite, it permits the in Fig. 1 illustrated measuring arrangement to determine the electrical charge of the satellite and the energy distribution in the electron cloud around the satellite, which consists mainly of photoelectrons, which are knocked out by irradiation of sunlight from the satellite, the satellite is highly positive charging.

In Fig. 1 shows a part of a satellite body 10, which may be, for example, the metallic outer skin of a spacecraft. On the satellite body 10, a spacer 12 is fixed, which consists of an electrically non-conductive material. To the spacer 12, an inner spherical grid 14 is fixed, which encloses an inner space 16. On the side facing away from the interior 16 side, the inner grid 14 is in turn surrounded by an outer grid 18, which is also spherical and concentric with the inner grid 14 is aligned.

The inner grid 14 and the outer grid 18 are made of an electrically conductive material. FIG. 2 shows the inner grid 14 and the outer grid 18 in a sectional view enlarged in comparison with FIG. 1 in order to make it clear that these grids are each a double grid. In the exemplary embodiment shown in FIG. 2, the double grids are mesh gratings with approximately the same optical transmission as possible per unit area. The inner grid 14 consists of a first sub-grid 20 and a second sub-grid 22. The outer grid 18 consists of a first sub-grid 24 and a second sub-grid 26. The sub-grid 20 to 26 are made of grid wires which are interconnected at their intersection points to achieve the required mechanical stability.

The design of the grids 14, 18 as a double lattice ensures that the electric field within the double lattice minimizes penetration through external electric fields. In the illustrated with reference to FIGS. 1 and 2 embodiment, the first sub-grid 20 of the inner grid 14 has a radius of 54 mm, the second sub-grid 22 of the inner grid 14 has a radius of 56 mm, the first sub-grid 24 of the outer grid 18 has a radius of 59 mm, and the second sub-grid of the outer grid 18 has a radius of 61 mm.

In the case of the internal grating 14 designed as a double lattice and in the case of the external grating 18 designed as a double lattice, the sublattices 20, 22 on the one hand and the sublattices 24, 26 on the other hand each have the same potential.

As can be seen in Fig. 1, the internal grating 14 is connected via a line 27 to a voltage source 28, which has a constant voltage Uj _G of 25 V in the described embodiment, to between the mass 30 of the satellite or body and the inner Grid 14 to provide a potential difference.

In the exemplary embodiment illustrated in FIG. 1, it can further be seen that the outer grid 18 is connected to a second voltage source 32, which is likewise connected to the ground 30. Another terminal of the second voltage source 32 is connected via an ammeter 34 and the line 35 to the outer grid 18. The

Ammeter 34 makes it possible to measure the current flowing through the outer grid 18 and to transmit the measured value via a measuring line 36 to a control and evaluation 38. The control and evaluation 38 is in turn connected to a unit for data output 40.

The control and evaluation electronics 38 are further connected via a control line 42 to the second voltage source 32, so that the output voltage of the second voltage source 32 can be set to predetermined values. The measuring line 36 and the control line 42 may be provided within the satellite as wire connections to the control and evaluation unit 38 or entirely or partially consist of telecommunication channels via which data can be exchanged between the satellite and a ground station.

The operation of the measuring arrangement shown in Fig. 1 will now be illustrated with reference to FIG. 3.

FIG. 3 shows how the output voltage UJ _{G of} the first voltage source 28 remains constant over the entire time period t, for example at a value of 25 V. The voltage and current characteristics illustrated in FIG. 3 are furthermore taken from that from the second voltage source 32 supplied voltage U _aG for the outer grid 18 initially has a value of -30 V, this value remains constant between the times t ₀ and ti.

During the period between times t ₀ and ti flows through the ammeter 34, a negative current U _G , which remains constant until the time at which the second voltage source 32 is switched via the control line 42 from -30 V to +30 V. Therefore, instead of a negative current, a positive current flows through the outer grid 18 from the time ti.

In the time interval t ₀ to ti, the photoelectrons located in the outer plasma around the satellite are repelled by the outer grating 18. The photoelectrons formed both in the outer grid 18 and in the inner grid 14 are likewise repelled by the outer grid 18, so that the negative current illustrated in FIG. 3 flows in the outer grid 14.

After switching the voltage U _aG at the time ti to +30 V and holding this voltage during the period of, for example, 30 seconds to the time t ₂ are in the outer grating 18 formed photoelectrons attracted, and the Photoelektronenstromanteil from the outer grid 18 goes to zero. A portion of the photoelectrons formed in the inner grid 14 also flows to the outer grid 18. In addition, now electrons are attracted to the lektronenwolke surrounding the satellite, so that in the outer grid 18 between the times ti and X _2, a constant positive current flows.

If the voltage U _aG , as seen in Fig. 3, after the steep rise to 30 V and a holding time between the times ti and X ₂ slowly until the time t ₃ to the original value drops again, gets an ever smaller part of Electrons from the inner grid 14 to the outer grid 18, since these are pushed back with uniformly decreasing voltage U _aG and only contribute negligibly to the current after a drop of the voltage U _aG below + 25V.

By analyzing the maximum value 44 and at U _aG = + 25 V, the analysis of the current I _aG allows a detection of the charging of the satellite, and by evaluating the falling edge 46 from the time X ₂ a detection of the energy distribution and density of the electrons in the Electron cloud around the satellite.

If the time t _{3 is} reached after a period of, for example, one minute after the time X ₂ , a new measurement cycle can be prepared and initiated, as illustrated in FIG. 3 by the second time t ₀ .

The voltage and current curves shown in FIG. 3 define a charging-measuring mode of the measuring arrangement in the manner described above. 4 shows a measuring arrangement which, like the measuring arrangement described with reference to FIGS. 1 to 3, has a satellite carrier 10 on which a spacer 12 is fastened, which in turn serves for fastening an inner grid 14 and an outer grid 18. The arrangement described so far corresponds to the arrangement described in connection with FIGS. 1 and 2.

In addition, the measuring arrangement shown in Fig. 4 has a metal ball 50 which is arranged in the interior 16 of the inner grid 14 concentric with the inner grid 14 and the outer grid 18. The spacer 12 thus serves in addition to the attachment of the metal ball 50. It has a Ausgasöffnung 52.

The metal ball 50 is electrically isolated from the satellite carrier 10 and has, for example, an outer radius of 50 mm at a thickness of 1 mm.

Electrically, the metal ball 50 is connected via a line 53 and an ammeter 54 to a third voltage source 56. The voltage source 56 is further connected to the ground 30 of the satellite.

The inner grid 14 is connected via the line 27 with the first voltage source 28 already described above in connection with the measuring arrangement according to FIG.

The outer grid 18 does not require a voltage source in the measuring arrangement shown in FIG. 4. For this reason, the line 35 is connected to the ground 30.

The control and evaluation 38 transmits control signals via the control line 58 to the first voltage source 28 and receives via the measuring line 60 information about the amount of current flowing through the ammeter 54 current. After a Evaluation of the current signals takes place on the data output 40 an output of the detected measured values for the energy distribution and the density of the electrons in the solar wind 55, which acts on the measuring arrangement according to FIG.

The operation under interaction of the various components of the measuring arrangement shown in Fig. 4 in the solar wind measuring mode will be explained below with reference to the course of the voltages across the three electrodes 14, 18 and 50 and the current flowing through the metal ball 50 as a third electrode current.

In the measuring arrangement shown in Fig. 4, the outer grid 18 is always on the line 35 at the ground potential of the satellite. Fig. 5 illustrates this situation in the context of the voltage U _3G , which is always 0V.

In FIG. 5 above, it can be seen that the metal ball 50 is also always subjected to a constant voltage, for example 15 V.

With the aid of the control and evaluation electronics 38, a control signal is sent to the first voltage source 28 via the signal line 58, so that it has the sawtooth-shaped profile in FIG. 5 between -50 V and +30 V. The voltage pulse U _iG has, for example, a length of 3 minutes between the cycle times t-π and U ₂ , and a length of less than one minute between the cycle times t _i2 and I ₁₃ .

In the period between the cycle times t ₁₀ and tu, a voltage U _lG of -50 V is applied to the inner grating 14. The outer grating 18 transmits ions and electrons having energies of more than 0 eV from the outer plasma toward the surface of the metal ball 50. The ions are trapped by the inner lattice 14, whereas the electrons with energies less than 50 eV do not overcome the negative potential of -50V can and can be pushed back. Since consequently no plasma components and especially electrons with less than 50 eV reach the metal ball 50, the current I _MK assumes its minimum value, especially since the photoelectrons formed in the metal ball 50 are picked up again by the metal ball 50. In the time interval between the clock times tu and t ₁₂ , the continuous increase of the voltage U _iG from the line 27 to the internal grating 14, illustrated in FIG. 5, is from -50 V to +30 V. In this case, electrons with higher energies can be the negative Overcome potential increasingly, the plasma electron current IMK through the ammeter 54 and the metal ball 50 increases to a maximum value, which is achieved in Fig. 5 at a voltage U _iG of about +15 V.

With a further increase of the voltage U _iG from +15 V to +30 V, plasma electrons with lower energies are increasingly intercepted by the inner lattice 14, which is why the plasma component in the current I _MK decreases again at the end of the time interval between ^ ₁ and t ₁₂ . The contributions of photoelectrons of the metal sphere 50 can be determined from measurements in the spectrometer measuring mode described below for voltage differences of UMK and Uj _G and used for correction.

The maximum value 62 of IMK which can be recognized in the lower curve in FIG. 5 is a measure of the electron density in the solar wind 55. The evaluation of the measurement curve l _M κ in the range between the instant ^ ₁ and the maximum 62 lying shortly before t ₁₂ permits a quantification the energy distribution of the electrons from the solar wind 55 or the suprathermal electrons from the ionosphere or the photoelectron cloud around the satellite as well as the electron temperature of the plasma surrounding the satellite. With the arrangement described, it is therefore also possible to detect coronal mass bursts of the sun. The energy of the electrons of the solar wind 55 surpasses the energy values of the other electrons, such as the ionospheric plasma and the photoelectrons, so that the corresponding current values of the latter can be separately analyzed in the measurements with the uniform change in the voltage of U _iG and assigned to different sources ,

The control and measuring electronics 38 contain programs for the required calculations or those data which allow to calibrate the measuring arrangement and to determine the sought measurement data on the basis of these values.

6 shows a spectrometer measuring arrangement for a spectrometer measuring mode. The measuring arrangement according to FIG. 6 serves to detect an extreme ultraviolet radiation 68 and has a mechanical structure which substantially corresponds to the structure described in connection with FIG. 4. Therefore, the same reference numerals have been used for corresponding components.

In contrast to the measuring arrangement according to FIG. 4, the measuring arrangement provided for the spectrometer measuring mode according to FIG. 6 has a second voltage source 32, which is already known from the measuring arrangement shown in FIG. The second voltage source 32 is connected via the line 35 directly and without ammeter to the outer grid 18.

In contrast to the arrangement according to FIG. 4, the first voltage source 28 is connected to the inner grid 14 via the line 27 with the interposition of an ammeter 64.

The third voltage source 56 known from FIG. 4 is connected to the metal ball 50 via the line 53 without the interposition of an ammeter. Notwithstanding the electrical circuit diagram shown in FIG. 4, the third voltage source 56 in the embodiment of FIG. 6 has a Control input, so that the control and evaluation 38 via a control line 66, the voltage supplied by the third voltage source 56 of the metal ball 50 voltage can change depending on the current measurement phase.

The function of the measuring arrangement according to FIG. 6 is illustrated in FIG. 7, which shows the course of the voltages at the three spherical electrodes, namely the two gratings 14, 18 and the metal ball 50, as well as the current profile to the inner grid 14 during different time intervals.

The voltage applied to the inner grid 14 is constant and in the embodiment shown has a value of about +25 V. The voltage delivered by the third voltage source 56 is constant at -30 V in the time interval t ₂ o to t ₂ i and has in the time interval t ₂ i to t ₂₂ the sawtooth waveform shown in Fig. 7 above between -30 V and +30 V. The time interval between the times t ₂ i and t ₂₂ while the metal ball 50 is supplied with a continuously increasing voltage U _MK , is for example 3 minutes.

On the outer grid 18 is via the line 35 a likewise variable between -30 V and +30 V variable voltage U _aG , which has the pulse shape shown in Fig. 7 and in the time interval between the times t ₂₄ and t ₂₅ their constant maximum value 69 of 30 V accepts. After the time t ₂₅ , the voltage U _aG on the outer grid 18 drops again to -30V, but the voltage drop to -30 V is much slower than the change in the rise time t ₂₄ .

In order to analyze the extreme ultraviolet radiation illustrated by lines 68 in Fig. 6, the current I _iG flowing in line 27 and measured by the ammeter 64 is measured by means of the measuring arrangement shown in Fig. 6 and in the control - And evaluation 38 evaluated. During the period between times t ₂ o and t ₂₁ are all drawn from the metal ball 50 due to a photoelectric effect of the extreme ultraviolet radiation 68 released photoelectrons onto the inner screen 14, where they cause a positive ven current value l _iG shown in Fig 7 is shown below.

Electrons from the plasma surrounding the measuring arrangement are forced back outward into the plasma due to the voltage U _aG of -30 V lying on the outer grid 18. Ions from the outer plasma are trapped by the outer grid 18. A portion of the photoelectrons triggered in the outer grid 18 also contributes to the current I _iG , which is marked in dashed lines in FIG. 7 as background current 70.

The current l _iG increases due to the above-mentioned voltage conditions in the time interval between times t ₂₀ and t ₂ i its maximum value a, which also supply sammensetzt the sum of the photoelectron currents of the metal ball 50 and to a lesser extent the photoelectron currents from the outer grid 18th

In FIG. 7 it can be seen that the control and evaluation unit 38 triggers an increase in the voltage U _MK at the metal ball 50 at the time t ₂ i. During the rise of the voltage U _MK in the period between the times t ₂ i and t ₂₂ , only higher energy photons from the metal sphere 50 originating from high-energy photons in the spectrum of the extreme ultraviolet radiation 68 contribute to the current I _g . The current I _iG decreases. During the time interval between the times t ₂₂ to t ₂₃ , the voltage U _M κ is continuously reduced to its initial value of -30 V and then remains constant.

The measurement error caused by the photoelectrons released by the outer grid 18 and also striking the inner grid 14 is due to the far smaller effective Surface of the outer grid 18 relative to the surface of the metal ball 50 is relatively small and illustrated by the line of the underground flow 70 in Fig. 7.

In order to determine the measurement error, the voltage U _aG at the outer grid 18 is increased in _pulses from -30 V to 30 V during the time interval between the times t ₂₄ and t _2δ . As a result, the photoelectrons emanating from the outer grid 18 are recaptured by the outer grid 18, and the maximum current value 72 is reduced to a lower current value 74, which is exaggerated in the current measurement curve for I _g as a brief dip in FIG. The reduction to the lower current value 74, starting from the maximum current value 72, makes it possible to determine the value for the correction of the maximum value by determining the current difference of both measurements.

The evaluation of corrected for the contribution of the photoelectrons from the outer grid current curve l _iG leads to quantify the spectrum of incident extreme ultraviolet radiation 68. The profile of the current curve 76 in the time interval between the time points t ₂ i and t ₂₂ allows using the control and evaluation electronics 38 to determine the total flow of the photoelectrons, which are released from the extreme ultraviolet radiation 68 from the metal ball 50. Furthermore, it allows the

Control and evaluation electronics 38, from the course of the current curve 76 by calculations or due to calibrations to detect the energy distribution of the photoelectrons that have been released by the photons of the extreme ultraviolet radiation 68.

The additional measurement of the current profile lj _G during the time interval between times t ₂₅ and t ₂₀ provides a corresponding correction _value for the evaluation for each voltage _value U _aG . This fine correction is used for Monitoring the possible influence of exceptionally strong, sun-based disturbances on the measured values. The control and evaluation electronics 38 make it possible to determine the energy distribution of the photoelectrons of the outer grid 18 from the time profile of the current to the inner grid 14 in the time interval between t ₂₅ and t ₂ o.

8 illustrates a measuring arrangement in which the measuring arrangements and measuring methods discussed in connection with FIGS. 1 to 7 are brought together in a measuring arrangement. The arrangement according to FIG. 8 makes it possible to detect solar extreme ultraviolet radiation 68, the solar wind 55, the charging of a satellite as well as incoming corpuscular and gamma radiation 78.

In Fig. 8 already known components are provided with the above-mentioned reference numerals. In addition, the measuring arrangement shown in FIG. 8 has inside the metal ball 50 scintillation crystals 80 which have different properties as illustrated by the hatchings. The scintillation crystals 80 are each assigned optical detectors 82 in order to receive the light signals triggered by cosmic radiation 78 in the scintillation crystals 80.

By matching the material, the metal ball 50, its wall thickness, possibly regularly distributed metal-coated window in the metal ball 50 and the wavelength sensitivity of the optical detectors 82, components of the cosmic rays can also be measured and evaluated with the aid of the scintillation electronics 84. The scintillation electronics 84 is connected by lines 86 and 88 to the control and evaluation 38. The scintillation electronics 84 contain input signals via lines 90, 92, which forward the electrical signals of the respective associated optical detectors 82 from the interior of the metal ball 50 to the scintillation electronics 84. Finally, it should be mentioned that the metal ball 50 does not necessarily have to have an ideal spherical surface. It may, for example, be a facet ball or even an arrangement with smaller flat mirrors. In extreme cases, an approximately space-symmetric, z. B. cubic geometry can be applied, whereby the accuracy of the measurements, however, is very limited.

Claims

claims

1. A measuring arrangement for detecting environmental parameters and operating parameters for a vacuum or space operating in the laboratory device, in particular a space-exposed solar wind and an extremely ultraviolet radiation and thereby electrically charged missile, characterized in that the missile ( 10) comprises an insulating spacer (12) on which as the first electrode a first inner electrically conductive grid (14), which encloses an inner space (16), and as a second electrode, a second outer grid (18), the inner grid ( 14) are enclosed, isolated from one another, wherein the inner grid (14) and the outer grid (18) can be acted on by a predetermined grid potential (27, 32) and the current flowing to the missile (10) depending on the respective potential the electrodes (14, 18) for obtaining data, in particular space weather data, can be evaluated.

2. Measuring arrangement according to claim 1, characterized in that the two grids enclose an electrically conductive hollow body (50) as a third electrode whose potential e- benfalls to a predetermined value (56) is adjustable.

3. Measuring arrangement according to one of the preceding claims, characterized in that the grids (14, 18) and the electrically conductive hollow body (50) are formed as three concentrically arranged electrodes having a substantially spherical shape.

4. Measuring arrangement according to one of the preceding claims, characterized in that the lattice each as a spherical a double-layered lattice is formed from two mesh gratings (20, 22, 24, 26) with high optical transmission.

5. Measuring arrangement according to claim 3 or 4, characterized in that in the interior of the spherical hollow body

(50) on cosmic radiation, in particular corpuscular radiation and gamma radiation responsive Szintillati- onskristalle (80) are arranged, the light from at least one optical detector (82) is detectable in the hollow body.

6. Measuring arrangement according to one of the preceding claims, characterized in that the three electrodes (14, 18, 50) via current measuring means (34, 54, 64) with their associated voltage sources (28, 32, 56) for the provision of the predetermined Potentials are connected.

7. A method for detecting the electrical charge of an ultra-ultraviolet radiation charged body, in particular a spaceflight exposed to sunlight, with the aid of a measuring arrangement according to one of the preceding claims, characterized in that the inner grid is placed at a constant positive voltage and the outer Grid is connected to a negative voltage, the pulse-shaped with a steep

Flank is raised to a positive value and then decreases again with a flat edge to the original negative value, wherein the occurring during the pulse maximum current in the outer grid as a measure of the charge of the body and the time course of the current drop during the falling edge of the voltage pulse for determining the density and energy distribution of the electron cloud formed by photoelectrons is evaluable around the missile.

8. A method for detecting Plasmaparametem, in particular of the solar wind in space by means of a measuring arrangement according to one of claims 2 to 6, characterized in that the outer grid is connected to ground potential and the third electrode to a fixed positive potential, and that during a Voltage rise at the inner grid, starting from a negative voltage to a positive voltage, the current through the third electrode is detected and evaluated by the maximum amplitude of the current of the third electrode from the

Density of the electrons of the solar wind and from the course of the increase of the current of the third electrode the energy distribution of the electrons of the solar wind is determined.

9. A method for quantifying the spectrum of ultraviolet radiation by means of a measuring arrangement according to claim 2 to 6, characterized in that the inner grid is acted upon by a constant positive voltage and the falling current through the inner grid at negative voltage remains constant outer grating during a rise of the voltage at the third electrode from a maximum negative value to a maximum positive value is evaluable to detect the energy distribution of the photons of the radiation, and that to reduce the measurement error, the high negative fixed voltage at the outer grid subsequently is briefly increased to a high positive voltage to reach from the then falling current in the inner grid a value for the correction of the maximum value, and that during the fall of the voltage at the outer grid of the short-term positive maximum value to the high negative fixed voltage is again evaluated in the inner grid to determine a Feinkor- rkturwert.

10. A method for detecting the corpuscular radiation and the gamma radiation in space by means of a Messanord- according to claim 5.

11. navigation satellite with a measuring arrangement according to one of claims 1 to 6.

12. A method for evaluating the signals of a navigation satellite, characterized in that to increase the accuracy of correction calculations are performed whose output parameters are determined using one of the method according to claim 7 to 10.