DE2455341B2 - Procedure for determining the wind profile of high-altitude winds - Google Patents

Description

A measurement of different vertical winds is hardly possible here. In addition, can only use the procedure in clear weather and over a limited altitude range.

Another, also in this publication> The method described consists in creating a corresponding columnar chaff cloud using a small Generate rocket and track the movement of the column by means of radar and a Doppler method. Practical tests of this process have shown, however, that this results in data about the desired Altitude range or with a desired spatial resolution can not be obtained.

The same applies to a procedure in which a column is formed by ionized air by means of a vertically directed ι> fuel element, which is then missed with radar. In this trial, carried out in 1965, higher Layers are not measured; See IEEE Transactions on Nuclear Science, April 1966, C. 54.> <>

A method for measuring wind by means of smoke strips is also described in DE-AS 1648 182. In this case, too, the measurable range only extends to heights of approximately one kilometer.

For a precise measurement of the wind speeds over several kilometers one is therefore essential dependent on procedures in which the trajectory of a body is measured; herewith are usable results can still be achieved most quickly.

Such a method is described in DE-AS 1008939. Here is an ejection probe from a Aircraft dropped and parachuted to earth, with the me-;. Theorological data are sent to the aircraft and received there until the probe has reached the ground is. This method, which is limited to the operating altitude of the aircraft, also has the disadvantage a very long measurement period and is very expensive, m Finally, such a flight is not without risk, especially in military operations.

Another method is to measure air speed using an acoustic probe like them in DE-AS 1965 126 is described. Here, the sound signals emitted from the ground are caused by air turbulence reflected and evaluated via the Doppler shift. The accuracy of this procedure is particularly low in the case of laminar horizontal currents. , "

Also one presented in the magazine "Air et Cosmos", issue no. 520, from March 9, 1974, on page 35 new device for the determination of wind speeds requires a very long measuring time. Here becomes a balloon probe of the usual Bauari, which with -> -> a radar reflector is provided, from the ground by means of a portable radar device on their ascent tracked. During the long measurement period, the wind conditions can again change considerably. A Another disadvantage is that inflating the balloon with hydrogen is also time consuming and also the production and transport of the hydrogen required for this is expensive.

There is therefore a considerable need for a simple and quickly implementable method for Determination of wind profiles.

The invention is based on the object of a new method for determining a wind profile specify the measurement time required for this for the discrete body and thus the entire Measurement time required for the process is significantly reduced.

This task is carried out according to de. ' Invention by the specified in the characterizing part of claim 1 Measures resolved.

Further developments of the invention are the subject of the subclaims.

In this way, for the first time, wind profiles over 10 to 20 kilometers in height can be recorded within a period of time can be measured from 2 to 4 minutes. In a military application, this results in significant ones tactical advantages, since in this case the probability is high that the actual wind profile at the time of the launch of a ballistic missile still corresponds to the one shortly before measured and taken into account in the ramp position. Also for the meteorological area significant benefits. This applies both to the time required for the measurement and to the results, which almost reflect an instantaneous distribution of wind speeds.

In principle, capsules with metal powder or chaff, which are in the respective Layers of air are released, or balloons ejected by the missile are used. Chaff clouds, however, have a very low rate of descent, while balloons again have the advantage that their rate of climb is independent of the air density, as long as there are no vertical ones Winds prevail. The burnt-out missile can also be used as one of the discrete bodies will. It is brought back to earth with a parachute.

On the measurement of the trajectories of the individual discrete bodies influenced by the wind The help of electromagnetic waves is not dealt with in more detail below, as this is done in a known manner he follows. In particular, a grid-like measurement of the trajectories of the individual bodies using radar merely by determining the spatial coordinates of the discrete bodies has proven to be particularly suitable here proven. Because the time available for measurement because of the relatively low speed the discrete body is relatively long, it is generally not necessary to make additional Doppler measurements to do. Optical tracking is also possible in areas close to the earth. The one in the survey The data obtained are entered into a computer. The calculator determines from these values the wind profile of the high-altitude winds according to speed and direction, with the normal rate of descent of the discrete body used in each case, depending on the altitude or the air density will.

When the method according to the invention is used in the military field, for example for Taking into account the influence of wind when launching ballistic missiles, the computer can process the data that provide automatic tracking of the start ramp during the countdown according to the determined wind profile enables. Since the measurement of wind speeds in the various Heights when carrying out the method is feasible within a very short period of time, reduced there is a risk that the wind speeds at the time of launch

have changed significantly.

The invention is explained in more detail with reference to the drawing. Here represents

1 shows a basic illustration, not to scale, of a method for determining the height-dependent Wind profile,

Fig. 2 schematically shows a missile which is used in the method,

3 shows a block diagram of a basic circuit for determining the wind profile,

4 shows a further embodiment of a missile, and

FIG. 5 shows a missile according to FIG. 4 after dismantling.

To determine the height-dependent wind profile a small rocket 1 is used, which consists of an engine part 11, which is a snow! burning single stage Thruster contains, and a part 12 consists of a plurality of discrete bodies 13, receives. These consist of a parachute 14 and one hanging from it and serving as a radar reflector Luneburg lens 15. The rocket 1 is launched vertically or at an angle - see reference number 1 ', after a short time it reaches the summit height marked 2 and then falls freely against the surface of the earth. At certain times, which are specified by means of a timer 16 arranged in the tip of the rocket the discrete bodies 13 are ejected from the missile. This itself will eventually afterwards braked by a parachute and reached the surface of the earth.

It is also possible that the engine part 11 of the part 12 is separated, and that the engine part with parachutes is returned to earth, while the z. B. aerodynamically by fold-out stabilizing fins Stably held part 12, as described above, descends in free fall.

A radar device 17 on a vehicle 18 pivots the entire height range in which the body 13 were ejected and gradually records their locality. These are saved and serve the next time you search the area to preset the antenna direction so that the body 13 can be detected more quickly.

The described search process is repeated cyclically so that it is possible after a few cycles Evaluation of the trajectories of the bodies 13 results in a grid of measured values and by interpolating the values obtained provide the wind profile over the entire measuring range with discrete measured values. This measurement method allows the coordinates of the individual discrete bodies 13 to be arbitrary when they are ejected can, so that the rocket 1 to maintain a target trajectory neither when climbing nor when falling needs.

For the pivoting of the antenna 31 of the radar device, a motor 32 with a coupled angle encoder 33 is provided, which indicates the angle w between the antenna direction and a reference direction; 3. This angle is fed to a sine and a cosine converter, 34 and 35, respectively, the outputs of which are connected to an input of a multiplier, 36 and 37, respectively.

In a circuit 38, the transit time Δ t of the amplified radar signal reflected by the Luneburg lenses 15 between the antenna and the Luneburg lens is determined and multiplied by the speed of light c. The distance r to the parachutes is now known. This measured value is fed to the second inputs of the multipliers 36 and 37, the outputs of which are the location coordinates χ and y of the appropriate parachute 13. These are z. B. entered an xy recorder 39, on which the wind profile is applied directly. In addition, the measured values χ and y are fed to a computer 40 in which the wind profile is calculated and at the outputs of which control signals for correcting the setting of a launch ramp for a ballistic missile can be picked up.

In Fig. 1, the measured wind profile is shown schematically by the interpolation of the total measured values obtained connection line shown.

It is for an exact and quick determination of the wind profile also for the indicated military Purpose sufficient if the discrete bodies are released about every 1000 meters. A wind profile can thus over an altitude of 10 to 20 km, which is about the altitude range of medium-range ballistic missiles corresponds to, using 10 to 20 parachutes and radar reflectors within 2 to 4 minutes can be measured.

In addition to the horizontal amounts of the height-dependent wind speeds, z. B. for the adjustment of the launch pad of ballistic missiles still the vertical components are important. In order to detect this, the part 12 of the rocket 1, as indicated in FIG. 2, has two measuring points 19 and 20 for measuring the static pressure ρ and the temperature T. From the measured values determined here and sent to the ground station, the respective air density can be calculated in the computer 40 and from this, since it influences the sinking speed of the parachutes 14 in a known manner, the vertical wind speeds can be calculated.

In general, the individual discrete bodies are not only recorded over their respective measuring path, which in the case described here is about 1000 meters; rather, it is for specific uses expedient, the individual discrete bodies each up to their impact on the ground to pursue. Most of the measuring sections are measured several times, so that the wind profile is also known in its temporal course, and thus the low-frequency turbulence of the individual Layers of air are determined. With these values z. B. a fine correction of the ramp division for Mid-range missiles possible.

Instead of ejecting the individual discrete bodies as the burnt-out missile falls, is It is possible to modify the missile in such a way that the upper part 12 consists of the individual discrete Bodies consists; See Fig. 4. As soon as the rocket has reached the top, the discrete bodies separated from each other and then each free fall in their respective bet height, where they in turn are slowed down by parachutes, which are deployed by means of a timer; see Fig. 5. It is favorable here if the discrete bodies are streamlined, d. H. a low aerodynamic Have resistance so that they get very quickly to their level of use.

The measurement of the wind profile is done in the same way as described above.

Of course, it is also possible to use the missile

and to destroy the individual discrete bodies in small parts before reaching the ground, so that one Endangering people is excluded. It can also be used to dismantle the rocket and trigger the deployment of the parachutes instead of the aforementioned

Zeitwerkes also an altimeter can be used or it can be triggered by remote control commands take place. Since these various possibilities are known as such, no further details are given on them received.

For this purpose 2 sheets of drawings

909 541/246

Claims (8)

Patent claims: 1. Procedure for determining the directional and Speed profiles of high-altitude winds over a certain altitude range in the a) a radar reflector is transported to a certain height by means of a rocket and there is released by the missile, b) the trajectory of the released and the direction of movement as well as the speed the radar reflector that has fallen through layers of air through radar sowing is determined from a ground station, characterized in that c) additional radar reflectors (13) are transported by means of the same rocket (1) will, d) the individual radar reflectors (13) within the altitude range to be monitored approximately equally spaced starting positions are brought, and e) the height range for the radar measurement for the purpose of repeated location of the individual Radar reflectors (13) is scanned cyclically. 2. The method according to claim 1, characterized in that the individual radar reflectors (13) when the burnt-out rocket (1) falls from it in the various starting positions released and slowed down there and that their speed of fall is reduced will. 3. The method according to claim 1, characterized in that that all radar reflectors (13) carried up to the top (2) of the rocket (1) and there be separated from the missile and from each other, and that the rate of fall of the individual radar reflectors after a period of time, the duration of which is different for each reflector is dimensioned, is reduced. 4. The method according to any one of the preceding claims 1 to 3, characterized in that Parachutes (14) designed to be reflective can be used as radar reflectors. 5. The method according to any one of claims 1 to 3, characterized in that as radar reflectors (13) Luneburg lenses (15) hanging on parachutes (14) can be used. 6. The method according to any one of the preceding claims, characterized in that the burned out Missile being used as one of the radar reflectors. 7. The method according to any one of the preceding claims, characterized in that the radar reflectors of a single or multi-stage missile with at least one attached non-powered, the radar reflectors receiving part (12) are transported. 8. The method according to any one of the preceding claims, characterized in that together with the radar reflectors a probe for obtaining atmospheric measurements as well as a Transmitters are carried up to transmit them to the ground station. The invention relates to a method according to the preamble of claim 1. A method for determining the wind profile in the mesosphere above 20 km altitude is in the journal ARS-Journal, August 61, page 1060ff., Described. This is done with the help of a rocket Body, for example a parachute, carried up to a summit height of about 60 to 70 km and then Approved; when the parachute drops ι ο measure its trajectory with radar, so that from this the prevailing high-altitude winds in the individual layers of air that have fallen through, according to speed and Direction can be calculated. For wind profile measurements from the ground up to approx. This procedure is not used at an altitude of 20 kilometers been; however, this height range is of particular interest in the military sector, for example in connection with the launch of a ballistic missile at a specific target. There 2 (i the wind conditions during the flight of the rocket can lead to considerable deviations from the target trajectory - it was found that approx. 60% to 80% of the determined scatter range is due to wind influences - the ramp for the launching of the r> ballistic missile in terms of elevation and azimuth depending on the wind profile in the individual to be corrected to air layers being flown through. Would use the specified method of determination the wind profile to the altitude range up to 20 KiIo- s "chirps would be transmitted because the rates of descent of parachutes become smaller with increasing air density, and in this altitude range are less than 10 meters per second, result in measurement times of over an hour. r> Because of this long measurement time it would be possible to that the actual wind strengths at the time of launch of the ballistic missile often no longer match the previously determined matched. The missile's fulfillment of the required mission is thus also with Elimination of all other errors is not guaranteed. Also from the pursuit of a rocket that snows the layers of air of interest! flies through, cannot achieve the desired wind profile with the necessary one r> Accuracy can be determined because, on the one hand, the vertical speed of the rocket is the horizontal Exceeds wind speed many times, d. H. the course changes due to wind influences only are very small, and further particularly in κι small missiles without major tax expense The rocket's wind behavior is difficult to separate from the other interfering influences. Since also Due to its relatively large inertia, the rocket reluctantly adapts to the effects of the wind and a sta- -, ι tional state only occurs when the wind speed is constant over long stretches of the rocket's trajectory is an exact measurement of the Wind profile with such a method is not possible. “Ο In a publication by NASA MARSHALL SPACE FLIGHT CENTER, March / April 1964, is open Page 183 of an article by Scoggins and Vaughan entitled "Atmospheric Wind Inputs for Missile Design «describes another process hi where a vertical column of smoke or steam from generated by a small rocket and this column in ■ is photographed at certain intervals. The exact center of the smoke column is difficult to determine.