Stepped beam instrument landing system

Claim 2

In combination: means disposed at a reference point for radiating an antenna pattern which is substantially omnidirectional about at least one axis in a predetermined time sequence; means disposed at said reference point for providing a plurality of time sequential spatially stepped antenna beams in a predetermined time sequence related to the time sequence of said omnidirectional pattern, said antenna beams defining a directional pattern relative to said reference point; signal processing means located aboard a craft and operative in response to said omnidirectional antenna pattern and said time sequential spatially stepped antenna beams to derive information functionally related to said reference point, said signal processing means including: means for receiviNg said omnidirectional antenna pattern and said stepped antenna beams; and means for deriving a signal varying as a function of the time difference of characteristics of the signals received from said omnidirectional antenna pattern and said stepped antenna beams.

Claim 3

The combination according to claim 1 wherein said signal processing means includes: means operative in response to said omnidirectional antenna pattern to provide a time reference; and means operative in response to said time sequential spatially stepped antenna beams to derive a weighted time center.

Claim 4

The combination according to claim 1 wherein said signal processing means includes: means operative in response to said received omnidirectional antenna pattern to provide a time reference; means operative in response to said received stepped antenna beams to compare the relative amplitudes thereof and to provide a weighted time center of said received beams; and means for determining the time difference between the occurrence of said time reference and said weighted time center.

Claim 5

The combination according to claim 1 wherein said signal processing means includes: circuitry for providing a first signal at a time representative of an intended craft direction relative to said reference point; circuitry for providing a second signal at a time representative of the actual craft direction relative to said reference point; and means for determining the time difference between the occurrence of said first and second signals, said time difference varying as a function of the direction of said craft from said reference point and the order of occurrence of said first and second signals being representative of the sense of the deviation from a predetermined direction.

Claim 6

An instrument landing system for determining craft direction from time sequential spatially stepped antenna beams, said system comprising: means disposed at a reference point for providing an omnidirectional antenna pattern in a predetermined time sequence; means disposed at said reference point for providing a plurality of time sequential spatially stepped antenna beams in a predetermined time sequence related to the time sequence of said omnidirectional pattern, said antenna beams defining a directional pattern relative to said reference point; signal processing means located aboard a craft and operative in response to said omnidirectional antenna pattern and said time sequential spatially stepped antenna beams to continuously determine craft direction relative to said reference point, said signal processing means including: means for receiving said omnidirectional antenna pattern and said stepped antenna beams; and means for deriving signals from said received antenna pattern and antenna beams representative of the direction of said craft relative to said reference point.

Claim 7

An instrument landing system for determining craft direction from time sequential spatially stepped antenna beams, said system comprising: means disposed at a reference point for providing an omnidirectional antenna pattern in a predetermined time sequence; means disposed at said reference point for providing a plurality of time sequential spatially stepped antenna beams in a predetermined time sequence related to the time sequence of said omnidirectional pattern, said antenna beams defining a directional pattern relative to said reference point; signal processing means located aboard a craft and operative in response to said omnidirectional antenna pattern and said time sequential spatially stepped antenna beams to continuously determine craft direction relative to said reference point, said signal processing means including: means for receiving said omnidirectional antenna pattern and said stepped antenna beams; and means for deriving signals from said received antenna pattern and antenna beams representative of the direction of said craft relative to said reference point.

Claim 8

The system according to claim 5 wherein said means for providing stepped antenna beams includes means for providing a plurality of time sequential spatially stepped antenna beams in both the azimuth plane and the elevation plane.

Claim 9

The system according to claim 5 wherein said signal processing means includes: means operative in response to said received omnidirectional antenna pattern to provide a time reference; means operative in response to said received time sequential spatially stepped antenna beams to derive a weighted time center thereof; and means for determining the time difference between the occurrence of said time reference and said weighted time center, said difference being representative of the position of said craft relative to said reference point.

Claim 10

The system according to claim 5 wherein said signal processing means includes: means operative in response to said received omnidirectional antenna pattern to provide a time reference; means operative in response to said received stepped antenna beams to compare the relative amplitudes thereof aNd to provide a weighted time center of said received beams; and means for determining the time difference between the occurrence of said time reference and said weighted time center, said time difference being representative of the direction of said craft relative to said reference point.

Claim 11

The system according to claim 5 wherein said signal processing means includes: circuitry for providing a first signal at a time representative of an intended craft direction relative to said reference point; circuitry for providing a second signal at a time representative of the actual craft direction relative to said reference point; and means for determining the time difference between the occurrence of said first and second signals, said time difference being representative of the deviation of the craft from said intended direction, and the order of occurrence of said first and second signals being representative of the sense of the deviation from said intended direction.

Claim 12

The system according to claim 6 wherein said signal processing means includes: means operative in response to said received omnidirectional antenna pattern to provide a time reference; means operative in response to said received time sequential spatially stepped antenna beams in both the azimuth plane and the elevation plane to derive a weighted time center thereof in respective planes; and means for determining the time difference between the occurrence of said time reference and each weighted time center, said time differences being representative of the direction of said craft in the azimuth and elevation planes relative to said reference point.

Claim 13

The system according to claim 6 wherein said signal processing means includes for each of said azimuth and elevation planes: a selector switch for manual selection of a digital number representative of an intended course angle; an angle clock for providing a sequence of digital numbers representative of possible course angles; circuitry for providing a first signal when the digital number from said selector switch and the digital number from said angle clock are equal; circuitry for providing a digital number representative of said craft direction; circuitry for providing a second signal when the digital number from said angle clock and the digital number of said craft direction are equal; gating means for providing pulses of a width proportional to the time difference between the occurrence of said first and second signals; and integrating means for providing an output signal of a magnitude proportional to the width of the pulses from said gating means, and representative of the deviation of the craft from said intended direction.

Claim 14

The system according to claim 11 including gating means for indicating the order of occurrence of said first and second signals thereby to indicate the sense of deviation from said intended direction.

Claim 15

The system according to claim 12 including means for displaying the magnitude and sense of deviation from said intended direction.

Claim 16

In combination: means disposed on a movable craft for detecting data signals modulated on energy patterns radiated from a predetermined locus, with a plurality of said detected energy patterns being substantially directionally radiated in a plurality of respectively different directions, with portions of adjacent of said directionally radiated energy patterns substantially mutually overlapping and with at least an additional one of said detected energy patterns overlapping at least the major portions of said directionally radiated energy patterns; and means on said movable craft fed by said detecting means for cyclically processing said detected data signals to produce a signal which varies as a function of the direction of said craft with respect to said locus.

Claim 17

In combination: means disposed on a movable craft for detecting data signals modulated on energy patterns radiated from a predetermined locus, with a plurality of said detected energy patterns being substantially directionally radiated in a plurality of respectively different directions, with portions of adjacent of said directionally radiated energy patterns substantially mutually overlapping and with at least an additional one of said detected energy patterns overlapping at least the major portions of said directionally radiated energy patterns; and means on said movable craft fed by said detecting means for cyclically processing said detected data signals to produce a signal which varies as a function of the direction of said craft with respect to said locus.

Claim 18

The combination according to claim 14 wherein each of said data signals comprises at least one pulse of a predetermined cyclical time sequence.

Claim 19

The combination according to claim 14 wherein the output of said processing means controls an indicator whose output varies as a function of the direction of said craft with respect to said locus.