JPH03295491A - Altitude detecting device for spacecraft - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an altitude detection device that is mounted on, for example, a spacecraft flying in an orbit around the earth and detects the altitude of the spacecraft from the surface of the earth.

[Prior Art] Conventionally, as shown in FIG. 4, the altitude of a spacecraft has been determined by ranging from a ground station (1).

[Problems to be solved by the invention] However, the conventional method requires a long time to determine the orbit, and when performing orbit control that involves large altitude changes, There is a drawback that a large attitude detection error occurs in the attitude sensor.

This invention was made to solve such problems, and its purpose is to enable a spacecraft to autonomously and in real time detect the altitude of its orbit without the support of a ground station.

[Means to solve the problem 1 A spacecraft altitude detection device according to this invention.

It consists of an infrared detection device that scans across the Earth at regular intervals and measures the time it takes to scan the Earth's surface, and a computer that processes the data.

[Operation] In this invention, since the time taken to scan the earth's surface measured by the infrared detection device changes depending on the change in the orbital altitude, the orbital altitude of the spacecraft is calculated by measuring the time taken to scan the earth's surface. It becomes possible to do so.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of an altitude detection device according to the present invention. In the figure, (2) is a reflecting mirror that vibrates at a fixed time interval, and reflects infrared rays emitted from the earth (3) to an infrared detector (4). Infrared detector (
4) outputs a pulse signal like (5), which is converted into a digital signal by an A/D converter (6) and then input to a computer (7).

FIG. 2 shows a processing method of one embodiment of the altitude detection device shown in FIG. In the figure, (8) is an infrared detector (4
) Manual data processing of the pulse signal after the A/D converter, and (9) format conversion to convert the digital signal into a data format suitable for processing.

(10) is an algorithm for calculating the time spent scanning the earth's surface, and (11) is an algorithm for calculating altitude.

FIG. 3 is a conceptual diagram of the altitude calculation algorithm shown in FIG. 2. In the figure, θ is the angle at which the surface of the earth (3) was scanned, T is the time at which the surface of the earth (3) was scanned, Re is the radius of the earth, and h is the altitude of the spacecraft.

ω is the angular velocity of the infrared reflector.

θ is determined from the time T during which the earth's surface is scanned using equation (1).

θ=ω・T ・・・・・・・・・
(1) The orbit height is calculated from θ using equation (2).

sin θ [Effects of the Invention] As described above, according to the present invention, there is an effect that the spacecraft can detect the orbital altitude autonomously and in real time without the support of a ground station.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of an embodiment of the orbit altitude detection device according to the present invention, Fig. 2 is a diagram showing a processing procedure for explaining the invention, and Fig. 3 is an explanation of the orbit altitude calculation algorithm. FIG. 4 is a diagram showing an example of a conventional method. In the figure, (1) is the ground station, (2) is the reflector, (3) is the earth, (4) is the infrared detector, and (5) is the pulse signal. (6) is an A/D converter, (7) is a computer, (8) is data input processing, and (9) is data format conversion. (10) is the scanning time calculation algorithm, and (11) is the altitude calculation algorithm. Note that the same line numbers in Figure 9 indicate the same or equivalent parts. Figure 1

Claims (1)

[Claims] Mounted on a spacecraft flying in Earth orbit, there is an infrared reflector that vibrates at a constant amplitude, an infrared detector that detects infrared rays from the earth, and a detection signal from this infrared detector that is processed and transmitted from the earth's surface. A spacecraft altitude detection device comprising: a computer for calculating the altitude of a spacecraft.