System for the course correction of a spinning projectile

Claim 2

System for determining the angular spin position of a second object spinning about an axis, where a first object emits electromagnetic waves and where the system is provided with directional receiving antenna means fitted to the second object, and with a receiving system which, using the receiving antenna means, process in combination the carrier waves received to obtain said angular spin position, characterised in that the received signals comprise at least one first polarised carrier wave and a second carrier wave which comprises phase information of the first carrier wave.

Claim 3

System as claimed in claim 1, characterised in that the second carrier wave has an amplitude modulation comprising a predetermined phase relation with the phase of the frequency of the first carrier wave.

Claim 4

System as claimed in claim 2, characterised in that the modulation concerns an amplitude modulation.

Claim 5

System as claimed in one of the claims 1-3, characterised in that the second carrier wave has a frequency which is not the same as the frequency of the first carrier wave.

Claim 6

System as claimed in claim 4, characterised in that the frequency of the first carrier wave is lower than the frequency of the second carrier wave.

Claim 7

System as claimed in one of the claims 3-5, characterised in that the phase of the amplitude modulation equals the phase of the frequency of the first carrier wave.

Claim 8

System as claimed in one of the above claims, characterised in that the second carrier wave is also suitable for sending information.

Claim 9

System as claimed in one of the above claims, characterised in that the receiving antenna means is at least provided with a first and a second directional antenna having a different orientation with respect to each other.

Claim 10

System as claimed in claim 8, characterised in that both antennas are perpendicularly disposed.

Claim 11

System as claimed in one of the claims 8 or 9, characterised in that the first and the second antenna are both provided with a loop antenna.

Claim 12

System as claimed in one of the above claims 8 or 9, characterised in that the first and the second antenna are both provided with a dipole antenna.

Claim 13

System as claimed in one of the above claims 1-7, characterised in that the receiving antenna means is provided with a loop antenna and a dipole antenna which are not perpendicularly disposed.

Claim 14

System as claimed in one of the claims 7-12, characterised in that the first and the second antenna are suitable for the reception of said carrier waves.

Claim 15

System as claimed in one of the claims 7-12, characterised in that the receiving antenna means is provided with a third antenna for the reception of the second carrier wave while the first and the second antenna are suitable for the reception of the first carrier wave.

Claim 16

System as claimed in one of the above claims 3-14, characterised in that the receiving system consist of: a. a reference unit for obtaining a reference signal from the second carrier wave received by means of the antenna system, the phase of the said reference signal having a predetermined relation with the phase of the carrier wave frequency of the said first carrier wave. b. a first and a second mixer for mixing with said reference signal the first carrier wave received by means of the first or the second antenna. c. a first and a second filter unit for filtering the output signals of said first and second mixers, said filters passing only frequency components equal or substantially equal to zero. d. a trigonometric unit controlled by the output signals of the first and second filters, which trigonometric unit generates a signal representing the instantaneous angle between one of the antennas and the polarisation direction of the carrier wave.

Claim 17

System as claimed in claims 13 and 15, characterised in that the reference unit comprises a phase-shifter for shifting the components of the first and second carrier wave, received by means of the first and second receiver, 90° with respect to each other, a summing unit for summing the components shifted in phase with respect to each other, and a demodulator for demodulating the summing signal of the summing unit where the demodulated signal is suitable to serve as reference signal.

Claim 18

System as claimed in claims 14 and 15, characterised in that the reference unit is provided with a demodulator for obtaining a reference signal from the second carrier wave received by means of the third antenna.

Claim 19

System as claimed in one of the claims 15-17, characterised in that the reference unit is provided with a filter for filtering out the data information from the second carrier wave received by means of the receiving antenna means.

Claim 20

System as claimed in one of the above claims, in which the second object consists of a projectile, characterised in that the said first and second antennas are connected to the projectile on the side turned away from the direction of flight.

Claim 21

System as claimed in one of the above claims, in which the second object is provided with a missile, characterised in that the fins of the missile serve as first and second antenna means.

Claim 22

System as claimed in claim 20, characterised in that the missile is provided with four fins where adjacent fins are positioned at 90° angles.

Claim 23

System as claimed in claim 15, characterised in that the trigonometric unit consists of a table-look-up generator generating φ from two input signals A cosφ and A sinφ.

Claim 24

System as claimed in claim 15, characterised in that the trigonometric unit consists of a computer calculating φ from two input signals A cosφ and A sinφ.

Claim 25

System as claimed in one of the above claims, where the first object is provided with a transmitter and antenna unit having such a range that the at least one carrier wave reaches up to and around the second object as well as down to the earth surface.

Claim 26

System as claimed in claim 24, where the orientation of the transmitter and antenna unit is not determined.

Claim 27

System as claimed in one of the above claims 24-25, where the angular spin position is measured of the second object with respect to the earth surface.

Claim 28

System as claimed in one of the above claims 24-26, where the first object concerns a vehicle and where the transmitter and antenna unit is rigidly or almost rigidly connected to the vehicle.

Claim 29

System as claimed in claim 27, where the vehicle is a ship.

Claim 30

System as claimed in one of the above claims 24-28, where the frequency of the first carrier wave is around 50 kHz.

Claim 31

First object suitable for use as described in one of the above claims.

Claim 32

Second object suitable for use as described in one of the above claims.

Claim 33

Projectile functioning as second object as described in claim 31.

Claim 34

Directional receiving antenna means suitable for use as described in one of the above claims 1-28.

Claim 35

Receiving system suitable for use as described in one of the above claims 1-28.

Claim 36

Vehicle provided with a transmitter and antenna unit and a transmitter as described in one of the above claims 1-28.