|  | G |
SECTION G — PHYSICS

|  | G |
Note(s) In this section, the following term is used with the meaning indicated: "variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes). Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class Fulltext... Hierarchy... Expanded...G01 and "control" and "regulation" in class Fulltext... Hierarchy... Expanded...G05. Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (Fulltext... Hierarchy... Expanded...G09), for enabling the result of a measurement to be known (Fulltext... Hierarchy... Expanded...G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (Fulltext... Hierarchy... Expanded...G08). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (Fulltext... Hierarchy... Expanded...G01L) or about some other condition linked to the pressure (another subclass of class Fulltext... Hierarchy... Expanded...G01, e.g., Fulltext... Hierarchy... Expanded...G01K for temperature), to make a record of the pressure or of its occurrence (Fulltext... Hierarchy... Expanded...G07C), to give an alarm (Fulltext... Hierarchy... Expanded...G08B), or to control another apparatus (Fulltext... Hierarchy... Expanded...G05). The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.

INSTRUMENTS

|  | G01 |
MEASURING (counting Fulltext... Hierarchy... Expanded...G06M); TESTING

|  | G01 |
Note(s) This class covers, in addition to "true" measuring instruments, other indicating or recording devices of analogous construction, and also signalling or control devices insofar as they are concerned with measurement (as defined in Note 2 below) and are not specially adapted to the particular purpose of signalling or control. In this class, the following term is used with the meaning indicated: "measuring" is used to cover considerably more than its primary or basic meaning. In this primary sense, it means finding a numerical expression of the value of a variable in relation to a unit or datum or to another variable of the same nature, e.g. expressing a length in terms of another length as in measuring a length with a scale; the value may be obtained directly (as just suggested) or by measuring some other variable of which the value can be related to the value of the required variable, as in measuring a change in temperature by measuring a resultant change in the length of a column of mercury. However, since the same device or instrument may, instead of giving an immediate indication, be used to produce a record or to initiate a signal to produce an indication or control effect, or may be used in combination with other devices or instruments to give a conjoint result from measurement of two or more variables of the same or different kinds, it is necessary to interpret "measuring" as including also any operation that would make it possible to obtain such a numerical expression by the additional use of some way of converting a value into figures. Thus the expression in figures may be actually made by a digital presentation or by reading a scale, or an indication of it may be given without the use of figures, e.g. by some perceptible feature (variable) of the entity (e.g. object, substance, beam of light) of which the variable being measured is a property or condition or by an analogue of such a feature (e.g. the corresponding position of a member without any scale, a corresponding voltage generated in some way). In many cases there is no such value indication but only an indication of difference or equality in relation to a standard or datum (of which the value may or may not be known in figures); the standard or datum may be the value of another variable of the same nature but of a different entity (e.g. a standard measure) or of the same entity at a different time. In its simplest form, measurement may give merely an indication of presence or absence of a certain condition or quality, e.g. movement (in any direction or in a particular direction), or whether a variable exceeds a predetermined value. Attention is drawn to the Notes following the title of section G, especially as regards the definition of the term "variable". In many measuring arrangements, a first variable to be measured is transformed into a second, or further, variables. The second, or further, variables may be (a) a condition related to the first variable and produced in a member, or (b) a displacement of a member. Further transformation may be needed. [6] When classifying such an arrangement, (i) the transformation step, or each transformation step, that is of interest is classified, or (ii) if interest lies only in the system as a whole, the first variable is classified in the appropriate place. [6] This is particularly important where two or more conversions take place, for instance where a first variable, for example pressure, is transformed into a second variable, for example an optical property of a sensing body, and that second variable is expressed by means of a third variable, for example an electric effect. In such a case, the following classification places should be considered: the place for the transformation of the first variable, that for sensing the condition caused by that variable, subclass Fulltext... Hierarchy... Expanded...G01D for expression of the measurement, and finally the place for the overall system, if any. [6] The measurement of change in the value of a physical property is classified in the same subclass as the measurement of that physical property, e.g. measurement of expansion of length is classified in subclass Fulltext... Hierarchy... Expanded...G01B.

|  | G01S |
RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES (detecting masses or objects by methods not involving reflection or reradiation of radio, acoustic or other waves Fulltext... Hierarchy... Expanded...G01V)

|  | G01S |
Note(s) In this subclass, the following term is used with the meaning indicated: [6] "transponder" means an arrangement which reacts to an incoming interrogating or detecting wave by emitting a specific answering or identifying wave. [6] Attention is drawn to the Notes following the title of class Fulltext... Hierarchy... Expanded...G01 and to Note (1) following the title of subclass Fulltext... Hierarchy... Expanded...G09B.

|  | G01S |
Subclass index
BEACON SYSTEMS; DIRECTION-FINDERS; POSITION FIXING | 1/00; 3/00; 5/00
RADAR OR ANALOGOUS SYSTEMS |
Details | 7/00
Using radio waves, using other waves where the wavelength or the kind of wave is irrelevant or unspecified | 13/00
Using acoustic waves | 15/00
Using electromagnetic waves other than radio waves | 17/00
SYSTEMS FOR DETERMINING DISTANCE OR VELOCITY NOT USING REFLECTION OR RERADIATION | 11/00

|  | G01S 1/00 |
Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith (position-fixing by co-ordinating a plurality of determinations of direction or position lines Fulltext... Hierarchy... Expanded...G01S 5/00) [2]

|  | G01S 1/02 |
· | using radio waves

|  | G01S 1/04 |
· · | Details

|  | G01S 1/06 |
· · · | Means for providing multiple indication, e.g. coarse and fine indications

|  | G01S 1/08 |
· · | Systems for determining direction or position line

|  | G01S 1/10 |
· · · | using amplitude comparison of signals transmitted sequentially from aerials or aerial systems having differently-oriented overlapping directivity-characteristics, e.g. equi-signal A-N type

|  | G01S 1/12 |
· · · · | the signals being transmitted sequentially from an aerial or aerial system having the orientation of its directivity characteristic periodically varied, e.g. by means of sequentially effective reflectors

|  | G01S 1/14 |
· · · | using amplitude comparison of signals transmitted simultaneously from aerials or aerial systems having differently-oriented overlapping directivity-characteristics

|  | G01S 1/16 |
· · · · | Azimuthal guidance systems, e.g. system for defining aircraft approach path, localiser system

|  | G01S 1/18 |
· · · · | Elevational guidance systems, e.g. system for defining aircraft glide path

|  | G01S 1/20 |
· · · | using a comparison of transit time of synchronised signals transmitted from non-directional aerials or aerial systems spaced apart, i.e. path-difference systems

|  | G01S 1/22 |
· · · · | the synchronised signals being frequency modulations on carrier waves and the transit times being compared by measuring difference of instantaneous frequencies of received carrier waves

|  | G01S 1/24 |
· · · · | the synchronised signals being pulses or equivalent modulations on carrier waves and the transit times being compared by measuring the difference in arrival time of a significant part of the modulations

|  | G01S 1/26 |
· · · · · | Systems in which pulses or time-base signals are generated locally at the receiver and brought into predetermined time-relationship with received signals, e.g. pulse duration coincides with time interval between arrival of significant part of modulation of signals received from first and second aerials or aerial systems

|  | G01S 1/28 |
· · · · · · | wherein the predetermined time-relationship is maintained automatically

|  | G01S 1/30 |
· · · · | the synchronised signals being continuous waves or intermittent trains of continuous waves, the intermittency not being for the purpose of determining direction or position line and the transit times being compared by measuring the phase difference

|  | G01S 1/32 |
· · · · · | Systems in which the signals received, with or without amplification, or signals derived therefrom, are compared in phase directly

|  | G01S 1/34 |
· · · · · | Systems in which first and second synchronised signals are transmitted from both aerials or aerial systems and a beat frequency, obtained by heterodyning the first signals with each other is compared in phase with a beat frequency obtained by heterodyning the second signals with each other

|  | G01S 1/36 |
· · · · · | Systems in which a beat frequency, obtained by heterodyning the synchronised signals, is compared in phase with a reference signal having a phase substantially independent of direction

|  | G01S 1/38 |
· · · | using comparison of (1) the phase of the envelope of the change of frequency, due to Doppler effect, of the signal transmitted by an aerial moving, or appearing to move, in a cyclic path with (2) the phase of a reference signal, the frequency of this reference signal being synchronised with that of the cyclic movement, or apparent cyclic movement, of the aerial

|  | G01S 1/40 |
· · · · | the apparent movement of the aerial being produced by cyclic sequential energisation of fixed aerials

|  | G01S 1/42 |
· · · | Conical-scan beam beacons transmitting signals which indicate at a mobile receiver any displacement of the receiver from the conical-scan axis, e.g. for "beam-riding" missile control [5]

|  | G01S 1/44 |
· · · | Rotating or oscillating beam beacons defining directions in the plane of rotation or oscillation [5]

|  | G01S 1/46 |
· · · · | Broad-beam systems producing at a receiver a substantially continuous sinusoidal envelope signal of the carrier wave of the beam, the phase angle of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon, e.g. cardioid system [5]

|  | G01S 1/48 |
· · · · · | wherein the phase angle of the direction-dependent envelope signal is a multiple of the direction angle, e.g. for "fine" bearing indication [5]

|  | G01S 1/50 |
· · · · · | wherein the phase angle of the direction-dependent envelope signal is compared with a non-direction- dependent reference signal [5]

|  | G01S 1/52 |
· · · · · | wherein the phase angles of a plurality of direction-dependent envelope signals produced by a plurality of beams rotating at different speeds or in different directions are compared [5]

|  | G01S 1/54 |
· · · · | Narrow-beam systems producing at a receiver a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon; Overlapping broad beam systems defining a narrow zone and producing at a receiver a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon [5]

|  | G01S 1/56 |
· · · · · | Timing the pulse-type envelope signals derived by reception of beam [5]

|  | G01S 1/58 |
· · · · · | wherein a characteristic of the beam transmitted or of an auxiliary signal is varied in time synchronously with rotation or oscillation of the beam [5]

|  | G01S 1/60 |
· · · · · · | Varying frequency of beam signal or of auxiliary signal [5]

|  | G01S 1/62 |
· · · · · · | Varying phase-relationship between beam and auxiliary signal [5]

|  | G01S 1/64 |
· · · · · · | Varying pulse timing, e.g. varying interval between pulses radiated in pairs [5]

|  | G01S 1/66 |
· · · · · · | Superimposing direction-indicating intelligence signals, e.g. speech, Morse [5]

|  | G01S 1/68 |
· · | Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information

|  | G01S 1/69 |
( covered by Fulltext... Hierarchy... Expanded...G01T 1/29 )

|  | G01S 1/70 |
· | using electromagnetic waves other than radio waves

|  | G01S 1/72 |
· | using ultrasonic, sonic, or infrasonic waves (signalling devices Fulltext... Hierarchy... Expanded...G08B)

|  | G01S 1/74 |
· · | Details [5]

|  | G01S 1/76 |
· · | Systems for determining direction or position line (sound focusing or directing using electrical steering of transducer arrays, e.g. beam steering, in general, Fulltext... Hierarchy... Expanded...G10K 11/34) [5]

|  | G01S 1/78 |
· · · | using amplitude comparison of signals transmitted from transducers or transducer systems having differently-oriented characteristics [5]

|  | G01S 1/80 |
· · · | using a comparison of transit time of synchronised signals transmitted from non-directional transducers or transducer systems spaced apart, i.e. path-difference systems [5]

|  | G01S 1/82 |
· · · | Rotating or oscillating beam beacons defining directions in the plane of rotation or oscillation [5]

|  | G01S 3/00 |
Direction-finders for determining the direction from which infrasonic, sonic, ultrasonic, or electromagnetic waves, or particle emission, not having a directional significance, are being received (position-fixing by co-ordinating a plurality of determinations of direction or position lines Fulltext... Hierarchy... Expanded...G01S 5/00; for geophysical measurement Fulltext... Hierarchy... Expanded...G01C; telescope mountings Fulltext... Hierarchy... Expanded...G02B)

|  | G01S 3/02 |
· | using radio waves

|  | G01S 3/04 |
· · | Details

|  | G01S 3/06 |
· · · | Means for increasing effective directivity, e.g. by combining signals having differently- oriented directivity characteristics, by sharpening the envelope waveform of the signal derived from a rotating or oscillating beam aerial (comparing amplitude of signals having differently-oriented directivity characteristics to determine direction Fulltext... Hierarchy... Expanded...G01S 3/16, Fulltext... Hierarchy... Expanded...G01S 3/28; modifications of aerials or aerial systems Fulltext... Hierarchy... Expanded...H01Q)

|  | G01S 3/08 |
· · · | Means for reducing polarisation errors, e.g. by use of Adcock or spaced loop aerial systems

|  | G01S 3/10 |
· · · | Means for reducing or compensating for quadrantal, site, or like errors

|  | G01S 3/12 |
· · · | Means for determining sense of direction, e.g. by combining signals from directional aerial or goniometer search coil with those from non-directional aerial (determining direction by amplitude comparison of signals derived by combining directional and non-directional signals Fulltext... Hierarchy... Expanded...G01S 3/24, Fulltext... Hierarchy... Expanded...G01S 3/34)

|  | G01S 3/14 |
· · | Systems for determining direction or deviation from predetermined direction

|  | G01S 3/16 |
· · · | using amplitude comparison of signals derived sequentially from receiving aerials or aerial systems having differently-oriented directivity characteristics or from an aerial system having periodically-varied orientation of directivity characteristic

|  | G01S 3/18 |
· · · · | derived directly from separate directional aerials

|  | G01S 3/20 |
· · · · | derived by sampling signal received by an aerial system having periodically-varied orientation of directivity characteristic

|  | G01S 3/22 |
· · · · | derived from different combinations of signals from separate aerials, e.g. comparing sum with difference

|  | G01S 3/24 |
· · · · · | the separate aerials comprising one directional aerial and one non-directional aerial, e.g. combination of loop and open aerials producing a reversed cardioid directivity characteristic

|  | G01S 3/26 |
· · · · · | the separate aerials having differently- oriented directivity characteristics

|  | G01S 3/28 |
· · · | using amplitude comparison of signals derived simultaneously from receiving aerials or aerial systems having differently-oriented directivity characteristics

|  | G01S 3/30 |
· · · · | derived directly from separate directional systems

|  | G01S 3/32 |
· · · · | derived from different combinations of signals from separate aerials, e.g. comparing sum with difference

|  | G01S 3/34 |
· · · · · | the separate aerials comprising one directional aerial and one non-directional aerial, e.g. combination of loop and open aerials producing a reversed cardioid directivity characteristic

|  | G01S 3/36 |
· · · · · | the separate aerials having differently- oriented directivity characteristics

|  | G01S 3/38 |
· · · | using adjustment of real or effective orientation of directivity characteristic of an aerial or an aerial system to give a desired condition of signal derived from that aerial or aerial system, e.g. to give a maximum or minimum signal (Fulltext... Hierarchy... Expanded...G01S 3/16, Fulltext... Hierarchy... Expanded...G01S 3/28 take precedence)

|  | G01S 3/40 |
· · · · | adjusting orientation of a single directivity characteristic to produce maximum or minimum signal, e.g. rotatable loop aerial, equivalent goniometer system

|  | G01S 3/42 |
· · · · | the desired condition being maintained automatically

|  | G01S 3/44 |
· · · · | the adjustment being varied periodically or continuously until it is halted automatically when the desired condition is attained

|  | G01S 3/46 |
· · · | using aerials spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems

|  | G01S 3/48 |
· · · · | the waves arriving at the aerials being continuous or intermittent and the phase difference of signals derived therefrom being measured

|  | G01S 3/50 |
· · · · | the waves arriving at the aerials being pulse modulated and the time difference of their arrival being measured

|  | G01S 3/52 |
· · · | using a receiving aerial moving, or appearing to move, in a cyclic path to produce a Doppler variation of frequency of the received signal

|  | G01S 3/54 |
· · · · | the apparent movement of the aerial being produced by coupling the receiver cyclically and sequentially to each of several fixed spaced aerials

|  | G01S 3/56 |
· · · | Conical-scan beam systems using signals indicative of the deviation of the direction of reception from the scan axis

|  | G01S 3/58 |
· · · | Rotating or oscillating beam systems using continuous analysis of received signal for determining direction in the plane of rotation or oscillation or for determining deviation from a predetermined direction in such a plane (Fulltext... Hierarchy... Expanded...G01S 3/14 takes precedence)

|  | G01S 3/60 |
· · · · | Broad-beam systems producing in the receiver a substantially-sinusoidal envelope signal of the carrier wave of the beam, the phase angle of which is dependent upon the angle between the direction of the transmitter from the receiver and a reference direction from the receiver, e.g. cardioid system

|  | G01S 3/62 |
· · · · · | wherein the phase angle of the signal is indicated by a cathode-ray tube

|  | G01S 3/64 |
· · · · · | wherein the phase angle of the signal is determined by phase comparison with a reference alternating signal varying in synchronism with the directivity variation

|  | G01S 3/66 |
· · · · | Narrow-beam systems producing in the receiver a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the transmitter from the receiver and a reference direction from the receiver; Overlapping broad-beam systems defining in the receiver a narrow zone and producing a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the transmitter from the receiver and a reference direction from the receiver

|  | G01S 3/68 |
· · · · · | wherein the timing of the pulse-type envelope signal is indicated by cathode-ray tube (radar cathode-ray tube indicators providing co-ordinated display of distance and direction Fulltext... Hierarchy... Expanded...G01S 7/10)

|  | G01S 3/70 |
· · · · · | wherein the timing of the pulse-type envelope signal is determined by bringing a locally-generated pulse-type signal into coincidence or other predetermined time-relationship with the envelope signal

|  | G01S 3/72 |
· · | Diversity systems specially adapted for direction-finding

|  | G01S 3/74 |
· · | Multi-channel systems specially adapted for direction-finding, i.e. having a single aerial system capable of giving simultaneous indications of the directions of different signals (systems in which the directions of different signals are determined sequentially and displayed simultaneously Fulltext... Hierarchy... Expanded...G01S 3/04, Fulltext... Hierarchy... Expanded...G01S 3/14)

|  | G01S 3/76 |
( covered by Fulltext... Hierarchy... Expanded...G01T 1/29 )

|  | G01S 3/78 |
· | using electromagnetic waves other than radio waves

|  | G01S 3/781 |
· · | Details [5]

|  | G01S 3/782 |
· · | Systems for determining direction or deviation from predetermined direction [5]

|  | G01S 3/783 |
· · · | using amplitude comparison of signals derived from static detectors or detector systems [5]

|  | G01S 3/784 |
· · · · | using a mosaic of detectors [5]

|  | G01S 3/785 |
· · · | using adjustment of orientation of directivity characteristics of a detector or detector system to give a desired condition of signal derived from that detector or detector system [5]

|  | G01S 3/786 |
· · · · | the desired condition being maintained automatically [5]

|  | G01S 3/787 |
· · · | using rotating reticles producing a direction-dependent modulation characteristic [5]

|  | G01S 3/788 |
· · · · | producing a frequency modulation characteristic [5]

|  | G01S 3/789 |
· · · | using rotating or oscillating beam systems, e.g. using mirrors, prisms [5]

|  | G01S 3/80 |
· | using ultrasonic, sonic, or infrasonic waves

|  | G01S 3/801 |
· · | Details [5]

|  | G01S 3/802 |
· · | Systems for determining direction or deviation from predetermined direction (sound-focusing or directing using electrical steering of transducer arrays, e.g. beam steering, in general, Fulltext... Hierarchy... Expanded...G10K 11/34) [5]

|  | G01S 3/803 |
· · · | using amplitude comparison of signals derived from receiving transducers or transducer systems having differently-oriented directivity characteristics [5]

|  | G01S 3/805 |
· · · | using adjustment of real or effective orientation of directivity characteristics of a transducer or transducer system to give a desired condition of signal derived from that transducer or transducer system, e.g. to give a maximum or minimum signal [5]

|  | G01S 3/807 |
· · · · | the desired condition being maintained automatically [5]

|  | G01S 3/808 |
· · · | using transducers spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems [5]

|  | G01S 3/809 |
· · · | Rotating or oscillating beam systems using continuous analysis of received signal for determining direction in the plane of rotation or oscillation or for determining deviation from a predetermined direction in such a plane [5]

|  | G01S 3/82 |
· · | with means for adjusting phase or compensating for time-lag errors

|  | G01S 3/84 |
· · | with indication presented on cathode-ray tubes

|  | G01S 3/86 |
· · | with means for eliminating undesired waves, e.g. disturbing noises

|  | G01S 5/00 |
Position-fixing by co-ordinating two or more direction or position-line determinations; Position-fixing by co-ordinating two or more distance determinations [2]

|  | G01S 5/02 |
· | using radio waves

|  | G01S 5/04 |
· · | Position of source determined by a plurality of spaced direction-finders

|  | G01S 5/06 |
· · | Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements (Fulltext... Hierarchy... Expanded...G01S 5/12 takes precedence) [3]

|  | G01S 5/08 |
· · | Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location

|  | G01S 5/10 |
· · | Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements (Fulltext... Hierarchy... Expanded...G01S 5/12 takes precedence) [3]

|  | G01S 5/12 |
· · | by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical, radial (radar indicators providing co-ordinated display of direction and distance Fulltext... Hierarchy... Expanded...G01S 7/10)

|  | G01S 5/14 |
· · | Determining absolute distances from a plurality of spaced points of known location

|  | G01S 5/15 |
( covered by Fulltext... Hierarchy... Expanded...G01T 1/29 )

|  | G01S 5/16 |
· | using electromagnetic waves other than radio waves

|  | G01S 5/18 |
· | using ultrasonic, sonic, or infrasonic waves

|  | G01S 5/20 |
· · | Position of source determined by a plurality of spaced direction-finders [5]

|  | G01S 5/22 |
· · | Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements (Fulltext... Hierarchy... Expanded...G01S 5/28 takes precedence) [5]

|  | G01S 5/24 |
· · | Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location [5]

|  | G01S 5/26 |
· · | Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements (Fulltext... Hierarchy... Expanded...G01S 5/28 takes precedence) [5]

|  | G01S 5/28 |
· · | by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical, radial (sonar indicators providing co-ordinated display of direction and distance Fulltext... Hierarchy... Expanded...G01S 7/62) [5]

|  | G01S 5/30 |
· · | Determining absolute distances from a plurality of spaced points of known location [5]

|  | G01S 7/00 |
Details of systems according to groups Fulltext... Hierarchy... Expanded...G01S 13/00, Fulltext... Hierarchy... Expanded...G01S 15/00, Fulltext... Hierarchy... Expanded...G01S 17/00

|  | G01S 7/02 |
· | of systems according to group Fulltext... Hierarchy... Expanded...G01S 13/00

|  | G01S 7/03 |
· · | Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver (TR boxes Fulltext... Hierarchy... Expanded...H01J 17/64; waveguides or resonators or other devices of the waveguide type Fulltext... Hierarchy... Expanded...H01P; aerials Fulltext... Hierarchy... Expanded...H01Q; basic electronic circuitry, e.g. generation of oscillations, modulation, demodulation, amplification, pulse technique Fulltext... Hierarchy... Expanded...H03; impedance networks, resonators Fulltext... Hierarchy... Expanded...H03H) [5]

|  | G01S 7/04 |
· · | Display arrangements

|  | G01S 7/06 |
· · · | Cathode-ray tube displays

|  | G01S 7/08 |
· · · · | with vernier indication of distance, e.g. using two cathode-ray tubes

|  | G01S 7/10 |
· · · · | Providing two-dimensional co-ordinated display of distance and direction

|  | G01S 7/12 |
· · · · · | Plan-position indicators, i.e. P. P. I.

|  | G01S 7/14 |
· · · · · · | Sector, off-centre, or expanded- angle display

|  | G01S 7/16 |
· · · · · | Signals displayed as intensity modulation with rectangular co-ordinates representing distance and bearing, e.g. type B

|  | G01S 7/18 |
· · · · · | Distance-height displays; Distance-elevation displays, e.g. type RHI, type E

|  | G01S 7/20 |
· · · · | Stereoscopic displays; Three-dimensional displays; Pseudo-three-dimensional displays

|  | G01S 7/22 |
· · · · | Producing cursor lines and indicia by electronic means

|  | G01S 7/24 |
· · · · | the display being orientated or displaced in accordance with movement of object carrying the transmitting and receiving apparatus, e.g. true-motion radar

|  | G01S 7/26 |
· · · | Displays using electroluminescent panels

|  | G01S 7/28 |
· · | Details of pulse systems

|  | G01S 7/282 |
· · · | Transmitters [5]

|  | G01S 7/285 |
· · · | Receivers [5]

|  | G01S 7/288 |
· · · · | Coherent receivers [5]

|  | G01S 7/292 |
· · · · | Extracting wanted echo-signals (Doppler systems Fulltext... Hierarchy... Expanded...G01S 13/50) [5]

|  | G01S 7/295 |
· · · · | Means for transforming co-ordinates or for evaluating data, e.g. using computers [5]

|  | G01S 7/298 |
· · · · · | Scan converters [5]

|  | G01S 7/32 |
· · · · | Shaping echo pulse signals; Deriving non-pulse signals from echo pulse signals [5]

|  | G01S 7/34 |
· · · · | Gain of receiver varied automatically during pulse-recurrence period, e.g. anti-clutter gain control [5]

|  | G01S 7/35 |
· · | Details of non-pulse systems [5]

|  | G01S 7/36 |
· · | Means for anti-jamming

|  | G01S 7/38 |
· · | Jamming means, e.g. producing false echoes [2]

|  | G01S 7/40 |
· · | Means for monitoring or calibrating

|  | G01S 7/41 |
· · | using analysis of echo signal for target characterisation; Target signature; Target cross-section [6]

|  | G01S 7/42 |
· · | Diversity systems specially adapted for radar

|  | G01S 7/48 |
· | of systems according to group Fulltext... Hierarchy... Expanded...G01S 17/00

|  | G01S 7/481 |
· · | Constructional features, e.g. arrangements of optical elements [6]

|  | G01S 7/483 |
· · | Details of pulse systems [6]

|  | G01S 7/484 |
· · · | Transmitters [6]

|  | G01S 7/486 |
· · · | Receivers [6]

|  | G01S 7/487 |
· · · · | Extracting wanted echo signals [6]

|  | G01S 7/489 |
· · · · | Gain of receiver varied automatically during pulse-recurrence period [6]

|  | G01S 7/491 |
· · | Details of non-pulse systems [6]

|  | G01S 7/493 |
· · · | Extracting wanted echo signals [6]

|  | G01S 7/495 |
· · | Counter-measures or counter-counter-measures [6]

|  | G01S 7/497 |
· · | Means for monitoring or calibrating [6]

|  | G01S 7/499 |
· · | using polarisation effects (measuring polarisation of light Fulltext... Hierarchy... Expanded...G01J) [6]

|  | G01S 7/50 |
( covered by Fulltext... Hierarchy... Expanded...G01S 7/48 )

|  | G01S 7/51 |
· · | Display arrangements [6]

|  | G01S 7/52 |
· | of systems according to group Fulltext... Hierarchy... Expanded...G01S 15/00

|  | G01S 7/521 |
· · | Constructional features (constructional features of transducers Fulltext... Hierarchy... Expanded...B06B; mounting transducers Fulltext... Hierarchy... Expanded...G10K 11/00) [6]

|  | G01S 7/523 |
· · | Details of pulse systems [6]

|  | G01S 7/524 |
· · · | Transmitters [6]

|  | G01S 7/526 |
· · · | Receivers [6]

|  | G01S 7/527 |
· · · · | Extracting wanted echo signals [6]

|  | G01S 7/529 |
· · · · | Gain of receiver varied automatically during pulse-recurrence period [6]

|  | G01S 7/53 |
· · · · | Means for transforming co-ordinates or for evaluating data, e.g. using computers [6]

|  | G01S 7/531 |
· · · · · | Scan converters [6]

|  | G01S 7/533 |
· · · · · | Data rate converters [6]

|  | G01S 7/534 |
· · | Details of non-pulse systems [6]

|  | G01S 7/536 |
· · · | Extracting wanted echo signals [6]

|  | G01S 7/537 |
· · | Counter measures or counter-counter-measures, e.g. jamming, anti-jamming [6]

|  | G01S 7/539 |
· · | using analysis of echo signal for target characterisation; Target signature; Target cross-section [6]

|  | G01S 7/54 |
· · | with receivers spaced apart

|  | G01S 7/56 |
· · | Display arrangements

|  | G01S 7/58 |
· · · | for providing variable ranges

|  | G01S 7/60 |
· · · | for providing a permanent recording

|  | G01S 7/62 |
· · · | Cathode-ray tube displays

|  | G01S 7/64 |
· · | Luminous indications (Fulltext... Hierarchy... Expanded...G01S 7/62 takes precedence) [5]

|  | G01S 7/66 |
( transferred to Fulltext... Hierarchy... Expanded...G01S 7/527, Fulltext... Hierarchy... Expanded...G01S 7/536 )

|  | G01S 11/00 |
Systems for determining distance or velocity not using reflection or reradiation (direction-finders Fulltext... Hierarchy... Expanded...G01S 3/00; position-fixing by co-ordinating two or more distance determinations Fulltext... Hierarchy... Expanded...G01S 5/00) [2]

|  | G01S 11/02 |
· | using radio waves [5]

|  | G01S 11/04 |
· · | using angle measurements [5]

|  | G01S 11/06 |
· · | using intensity measurements [5]

|  | G01S 11/08 |
· · | using synchronised clocks (synchronisation of electronic clocks Fulltext... Hierarchy... Expanded...G04G 7/02) [5]

|  | G01S 11/10 |
· · | using Doppler effect [5]

|  | G01S 11/12 |
· | using electromagnetic waves other than radio waves [5]

|  | G01S 11/14 |
· | using ultrasonic, sonic or infrasonic waves [5]

|  | G01S 11/16 |
· | using difference in transit time between electromagnetic and sonic waves [5]

|  | G01S 13/00 |
Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified (using acoustic waves Fulltext... Hierarchy... Expanded...G01S 15/00; using electromagnetic waves other than radio waves Fulltext... Hierarchy... Expanded...G01S 17/00) [3]

|  | G01S 13/00 |
Note(s) This group covers: systems for detecting the presence of an object, e.g. by reflection or reradiation from the object itself, or from a transponder associated with the object, for determining the distance or relative velocity of an object, for providing a co-ordinated display of the distance and direction of an object or for obtaining an image thereof; [3] systems arranged for mounting on a moving craft or vehicle and using the reflection of waves from an extended surface external to the craft, e.g. the surface of the earth, to determine the velocity and direction of motion of the craft relative to the surface. [3] This group does not cover: systems for determining the direction of an object by means not employing reflection or reradiation, which are covered by groups Fulltext... Hierarchy... Expanded...G01S 1/00 or Fulltext... Hierarchy... Expanded...G01S 3/00; [3] systems for determining distance or velocity of an object by means not employing reflection or reradiation, which are covered by group Fulltext... Hierarchy... Expanded...G01S 11/00. [3]

|  | G01S 13/02 |
· | Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems [3]

|  | G01S 13/04 |
· · | Systems determining presence of a target (based on relative movement of target Fulltext... Hierarchy... Expanded...G01S 13/56) [3]

|  | G01S 13/06 |
· · | Systems determining position data of a target [3]

|  | G01S 13/08 |
· · · | Systems for measuring distance only (indirect measurement Fulltext... Hierarchy... Expanded...G01S 13/46) [3]

|  | G01S 13/10 |
· · · · | using transmission of interrupted pulse modulated waves (determination of distance by phase measurement Fulltext... Hierarchy... Expanded...G01S 13/32) [3]

|  | G01S 13/12 |
· · · · · | wherein the pulse-recurrence frequency is varied to provide a desired time relationship between the transmission of a pulse and the receipt of the echo of a preceding pulse [3]

|  | G01S 13/14 |
· · · · · | wherein a voltage or current pulse is initiated and terminated in accordance respectively with the pulse transmission and echo reception [3]

|  | G01S 13/16 |
· · · · · · | using counters [3]

|  | G01S 13/18 |
· · · · · | wherein range gates are used [3]

|  | G01S 13/20 |
· · · · · | whereby multiple time-around echos are used or eliminated [3]

|  | G01S 13/22 |
· · · · · | using irregular pulse repetition frequency [3]

|  | G01S 13/24 |
· · · · · | using frequency agility of carrier wave [3]

|  | G01S 13/26 |
· · · · · | wherein the transmitted pulses use a frequency- or phase-modulated carrier wave [3]

|  | G01S 13/28 |
· · · · · · | with time compression of received pulses [3]

|  | G01S 13/30 |
· · · · · | using more than one pulse per radar period [3]

|  | G01S 13/32 |
· · · · | using transmission of continuous unmodulated waves, amplitude-, frequency- or phase-modulated waves [3]

|  | G01S 13/34 |
· · · · · | using transmission of frequency-modulated waves and the received signal, or a signal derived therefrom, being heterodyned with a locally-generated signal related to the contemporaneous transmitted signal to give a beat-frequency signal [3]

|  | G01S 13/36 |
· · · · · | with phase comparison between the received signal and the contemporaneously transmitted signal [3]

|  | G01S 13/38 |
· · · · · · | wherein more than one modulation frequency is used [3]

|  | G01S 13/40 |
· · · · · · | wherein the frequency of transmitted signal is adjusted to give a predetermined phase relationship [3]

|  | G01S 13/42 |
· · · | Simultaneous measurement of distance and other coordinates (indirect measurement Fulltext... Hierarchy... Expanded...G01S 13/46) [3]

|  | G01S 13/44 |
· · · · | Monopulse radar, i.e. simultaneous lobing [3]

|  | G01S 13/46 |
· · · | Indirect determination of position data [3]

|  | G01S 13/48 |
· · · · | using multiple beams at emission or reception [3]

|  | G01S 13/50 |
· · | Systems of measurement based on relative movement of target [3]

|  | G01S 13/52 |
· · · | Discriminating between fixed and moving objects or between objects moving at different speeds [3]

|  | G01S 13/522 |
· · · · | using transmissions of interrupted pulse modulated waves [5]

|  | G01S 13/524 |
· · · · · | based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi (coherent receivers Fulltext... Hierarchy... Expanded...G01S 7/288) [5]

|  | G01S 13/526 |
· · · · · · | performing filtering on the whole spectrum without loss of range information, e.g. using delay line cancellers or comb filters [5]

|  | G01S 13/528 |
· · · · · · · | with elimination of blind speeds [5]

|  | G01S 13/53 |
· · · · · · | performing filtering on a single spectral line and associated with one or more range gates with a phase detector or a frequency mixer to extract the Doppler information, e.g. pulse Doppler radar [5]

|  | G01S 13/532 |
· · · · · · · | using a bank of range gates or a memory matrix [5]

|  | G01S 13/534 |
· · · · · · | based upon amplitude or phase shift resulting from movement of objects, with reference to the surrounding clutter echo signal, e.g. non-coherent MTi, clutter referenced MTi, externally coherent MTi [5]

|  | G01S 13/536 |
· · · · | using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves [5]

|  | G01S 13/538 |
· · · · | eliminating objects that have not moved between successive antenna scans, e.g. area MTi [5]

|  | G01S 13/56 |
· · · · | for presence detection [3]

|  | G01S 13/58 |
· · · | Velocity or trajectory determination systems; Sense-of-movement determination systems [3]

|  | G01S 13/60 |
· · · · | wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track (Fulltext... Hierarchy... Expanded...G01S 13/64 takes precedence) [3]

|  | G01S 13/62 |
· · · · | Sense-of-movement determination [3]

|  | G01S 13/64 |
· · · · | Velocity measuring systems using range gates [3]

|  | G01S 13/66 |
· | Radar-tracking systems; Analogous systems [3]

|  | G01S 13/68 |
· · | for angle tracking only [3]

|  | G01S 13/70 |
· · | for range tracking only [3]

|  | G01S 13/72 |
· · | for two-dimensional tracking, e.g. combination of angle and range tracking, track-while-scan radar [3]

|  | G01S 13/74 |
· | Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems [3,6]

|  | G01S 13/75 |
· · | using transponders powered from received waves, e.g. using passive transponders [6]

|  | G01S 13/76 |
· · | wherein pulse-type signals are transmitted [3]

|  | G01S 13/78 |
· · · | discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe (Fulltext... Hierarchy... Expanded...G01S 13/75, Fulltext... Hierarchy... Expanded...G01S 13/79 takes precedence) [3]

|  | G01S 13/79 |
· · | Systems using random coded signals or random pulse repetition frequencies [6]

|  | G01S 13/80 |
( transferred to Fulltext... Hierarchy... Expanded...G01S 13/75, Fulltext... Hierarchy... Expanded...G01S 13/79 )

|  | G01S 13/82 |
· · | wherein continuous-type signals are transmitted [3]

|  | G01S 13/84 |
· · · | for distance determination by phase measurement [3]

|  | G01S 13/86 |
· | Combinations of radar systems with non-radar systems, e.g. sonar, direction finder [3]

|  | G01S 13/87 |
· | Combinations of radar systems, e.g. primary radar and secondary radar [3]

|  | G01S 13/88 |
· | Radar or analogous systems, specially adapted for specific applications (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01S 13/89-G01S 13/95 take precedence; electromagnetic prospecting or detecting of objects, e.g. near-field detection, Fulltext... Hierarchy... Expanded...G01V 3/00) [3,6]

|  | G01S 13/89 |
· | Radar or analogous systems, designed for mapping or imaging [3]

|  | G01S 13/90 |
· · | using synthetic aperture techniques [3,6]

|  | G01S 13/91 |
· | Radar or analogous systems, designed for traffic control (Fulltext... Hierarchy... Expanded...G01S 13/93 takes precedence) [3]

|  | G01S 13/92 |
· · | for velocity measurement [3]

|  | G01S 13/93 |
· | Radar or analogous systems, designed for anti-collision purposes [3]

|  | G01S 13/94 |
· | Radar or analogous systems, designed for terrain-avoidance [3]

|  | G01S 13/95 |
· | Radar or analogous systems, designed for meteorological use [3]

|  | G01S 15/00 |
Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems [3]

|  | G01S 15/00 |
Note(s) The Notes following group Fulltext... Hierarchy... Expanded...G01S 13/00 also apply to this group. [3]

|  | G01S 15/02 |
· | using reflection of acoustic waves (Fulltext... Hierarchy... Expanded...G01S 15/66 takes precedence) [3]

|  | G01S 15/04 |
· · | Systems determining presence of a target [3]

|  | G01S 15/06 |
· · | Systems determining position data of a target [3]

|  | G01S 15/08 |
· · · | Systems for measuring distance only (indirect measurement Fulltext... Hierarchy... Expanded...G01S 15/46) [3]

|  | G01S 15/10 |
· · · · | using transmission of interrupted pulse-modulated waves (determination of distance by phase measurement Fulltext... Hierarchy... Expanded...G01S 15/32) [3]

|  | G01S 15/12 |
· · · · · | wherein the pulse-recurrence frequency is varied to provide a desired time relationship between the transmission of a pulse and the receipt of the echo of a preceding pulse [3]

|  | G01S 15/14 |
· · · · · | wherein a voltage or current pulse is initiated and terminated in accordance respectively with the pulse transmission and echo reception [3]

|  | G01S 15/18 |
· · · · · | wherein range gates are used [3]

|  | G01S 15/32 |
· · · · | using transmission of continuous unmodulated waves, amplitude-, frequency- or phase-modulated waves [3]

|  | G01S 15/34 |
· · · · · | using transmission of frequency-modulated waves and the received signal, or a signal derived therefrom, being heterodyned with a locally-generated signal related to the contemporaneous transmitted signal to give a beat-frequency signal [3]

|  | G01S 15/36 |
· · · · · | with phase comparison between the received signal and the contemporaneously transmitted signal [3]

|  | G01S 15/42 |
· · · | Simultaneous measurement of distance and other coordinates (indirect measurement Fulltext... Hierarchy... Expanded...G01S 15/46) [3]

|  | G01S 15/46 |
· · · | Indirect determination of position data [3]

|  | G01S 15/50 |
· · | Systems of measurement based on relative movement of target [3]

|  | G01S 15/52 |
· · · | Discriminating between fixed and moving objects or between objects moving at different speeds [3]

|  | G01S 15/58 |
· · · | Velocity or trajectory determination systems; Sense-of-movement determination systems [3]

|  | G01S 15/60 |
· · · · | wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track [3]

|  | G01S 15/62 |
· · · · | Sense-of-movement determination [3]

|  | G01S 15/66 |
· | Sonar tracking systems [3]

|  | G01S 15/74 |
· | Systems using reradiation of acoustic waves, e.g. IFF, i.e. identification of friend or foe [3]

|  | G01S 15/87 |
· | Combinations of sonar systems [3]

|  | G01S 15/88 |
· | Sonar systems, specially adapted for specific applications (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01S 15/89-G01S 15/96 take precedence; seismic or acoustic prospecting or detecting Fulltext... Hierarchy... Expanded...G01V 1/00) [3,6]

|  | G01S 15/89 |
· | Sonar systems designed for mapping or imaging [3]

|  | G01S 15/93 |
· | Sonar systems designed for anti-collision purposes [3]

|  | G01S 15/96 |
· | Sonar systems designed for locating fish [3]

|  | G01S 17/00 |
Systems using the reflection or reradiation of electromagnetic waves other than radio waves [3]

|  | G01S 17/00 |
Note(s) The Notes following group Fulltext... Hierarchy... Expanded...G01S 13/00 also apply to this group. [3]

|  | G01S 17/02 |
· | Systems using the reflection of electromagnetic waves other than radio waves (Fulltext... Hierarchy... Expanded...G01S 17/66 takes precedence) [3]

|  | G01S 17/06 |
· · | Systems determining position data of a target [3]

|  | G01S 17/08 |
· · · | for measuring distance only (indirect measurement Fulltext... Hierarchy... Expanded...G01S 17/46; using a parallactic triangle Fulltext... Hierarchy... Expanded...G01C 3/10, Fulltext... Hierarchy... Expanded...G01C 3/22, Fulltext... Hierarchy... Expanded...G01C 3/24, Fulltext... Hierarchy... Expanded...G01C 3/26) [3]

|  | G01S 17/10 |
· · · · | using transmission of interrupted pulse-modulated waves (determination of distance by phase measurements Fulltext... Hierarchy... Expanded...G01S 17/32) [3]

|  | G01S 17/32 |
· · · · | using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves [3]

|  | G01S 17/36 |
· · · · · | with phase comparison between the received signal and the contemporaneously transmitted signal [3]

|  | G01S 17/42 |
· · · | Simultaneous measurement of distance and other coordinates (indirect measurement Fulltext... Hierarchy... Expanded...G01S 17/46) [3]

|  | G01S 17/46 |
· · · | Indirect determination of position data [3]

|  | G01S 17/50 |
· · | Systems of measurement based on relative movement of target [3]

|  | G01S 17/58 |
· · · | Velocity or trajectory determination systems; Sense-of-movement determination systems [3]

|  | G01S 17/66 |
· | Tracking systems using electromagnetic waves other than radio waves [3]

|  | G01S 17/74 |
· | Systems using reradiation of electromagnetic waves other than radio waves, e.g. IFF, i.e. identification of friend or foe [3]

|  | G01S 17/87 |
· | Combinations of systems using electromagnetic waves other than radio waves [3]

|  | G01S 17/88 |
· | Lidar systems, specially adapted for specific applications (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01S 17/89-G01S 17/95 take precedence) [3]

|  | G01S 17/89 |
· | Lidar systems designed for mapping or imaging [6]

|  | G01S 17/93 |
· | Lidar systems designed for anti-collision purposes [6]

|  | G01S 17/95 |
· | Lidar systems designed for meteorological use [6]