Alignment system and method for optical satellite communication
First Claim
1. An alignment calibration system for use in a first optical communication terminal communicating with a second optical communication terminal, comprising:
- a modulator that modulates a first data signal with a first alignment signal representative of an alignment offset taken by the first optical communication terminal during transmission of the first data signal by the first optical communication terminal to the second optical communication terminal;
a demodulator responsive to a second data signal transmitted by the second optical communication terminal wherein the demodulator develops a second alignment signal representative of the alignment offset taken by the first optical communication terminal and an intensity of the first data signal as received by the second optical communication terminal;
a processor coupled to the demodulator and configured to determine an optimal alignment position from the alignment offset and the intensity.
1 Assignment
0 Petitions
Accused Products
Abstract
An optical communication terminal transmits data via an optical signal with a transmit mirror positioned to direct the optical signal. The optical communication terminal includes a processor configured to develop a control signal for a mirror controller to establish an optimal position of the transmit mirror. The optical communication terminal further includes a modulator coupled to the processor that modulates the optical signal in accordance with a position of the transmit mirror during transmission of the optical signal. The optimal position of the transmit mirror may be established by a scanning routine that adjusts the position of the transmit mirror to a plurality of predetermined offset positions during transmission of the optical signal. The intensity of the optical signal as received by a further optical communication terminal is then determined and provided via modulation of a further optical signal transmitted back to the first-named optical communication terminal. The predetermined offset positions and the corresponding received intensities may then be utilized to determine the optimal position of the transmit mirror.
-
Citations
25 Claims
-
1. An alignment calibration system for use in a first optical communication terminal communicating with a second optical communication terminal, comprising:
-
a modulator that modulates a first data signal with a first alignment signal representative of an alignment offset taken by the first optical communication terminal during transmission of the first data signal by the first optical communication terminal to the second optical communication terminal;
a demodulator responsive to a second data signal transmitted by the second optical communication terminal wherein the demodulator develops a second alignment signal representative of the alignment offset taken by the first optical communication terminal and an intensity of the first data signal as received by the second optical communication terminal;
a processor coupled to the demodulator and configured to determine an optimal alignment position from the alignment offset and the intensity. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of aligning a first communication terminal with a second communication terminal for optical transmission of data between the first communication terminal and the second communication terminal, the method comprising the steps of:
-
(a) adjusting a mirror of the first communication terminal to a first position;
(b) modulating a first optical signal representative of the data in accordance with the first position;
(c) transmitting the first optical signal from the first communication terminal to the second communication terminal;
(d) receiving a second optical signal from the second communication terminal to obtain an intensity of the first optical signal as received by the second communication terminal; and
(e) adjusting the mirror of the first communication terminal to a second position. - View Dependent Claims (8, 9, 10, 11, 12, 13)
-
-
14. A method of aligning a first communication terminal and a second communication terminal, the method comprising the steps of:
-
(a) adjusting a mirror of the first communication terminal to a plurality of predetermined offset positions from a first position;
(b) transmitting, for each predetermined offset position, a respective first optical signal from the first communication terminal to the second communication terminal wherein each first optical signal is representative of the corresponding predetermined offset position;
(c) receiving, for each predetermined offset position, a respective second optical signal from the second communication terminal to the first communication terminal wherein each second optical signal is representative of a respective intensity of the corresponding first optical signal as received by the second communication terminal; and
(d) adjusting the mirror of the first communication terminal to a second position based on the plurality of predetermined offset positions and the corresponding received intensities. - View Dependent Claims (15, 16, 17, 18, 19, 20)
generating an intensity estimation function from the plurality of predetermined offset positions and the corresponding intensities; and
determining an optimal mirror position from the intensity estimation function.
-
-
16. The method of claim 15, wherein the intensity estimation function generating step comprises the step of computing a parabolic fit for the intensities as received by the second communication terminal.
-
17. The method of claim 16, wherein the computing step comprises the step of calculating coefficients for the parabolic fit via least-squares analysis.
-
18. The method of claim 14, wherein step (b) comprises the step of modulating an optical carrier signal with a subcarrier signal representative of the corresponding predetermined offset position to generate each first optical signal.
-
19. The method of claim 18, wherein the optical carrier signal is representative of data transmitted between the first communication terminal and the second communication terminal.
-
20. The method of claim 14, wherein:
-
step (c) comprises the step of demodulating an optical carrier signal with a subcarrier signal representative of the respective predetermined offset position and the corresponding received intensity; and
the optical carrier signal is representative of data transmitted between the first communication terminal and the second communication terminal.
-
-
21. A method of controlling a mirror positioning system for an optical communication terminal, the method comprising the steps of:
-
(a) receiving intensity data associated with optical transmission of content at a plurality of mirror offset positions established by the mirror positioning system; and
(b) determining an optimal mirror position to maximize transmission intensity via a parabolic fit of the intensity data. - View Dependent Claims (22, 23, 24, 25)
-
Specification