1、62 IRE 12. SI SH-0104-O IRE STANDARDS ON NAVIGATION AIDS: DEFINITIONS OF INERTIAL NAVIGATION TERMS, 1962 3 IRE Standards on Navigation Aids: Definitions of Inertial Navigation Terms, 1962* 62 IRE 12. Sl COMMITTEE PERSONNEL Navigation Aids Committee 1960-1963 . I. METZ, Chairman 1960-1963 . . CASABON
2、A, Vice Chairman 1960-1961 A. G. Richardson, Vice Chairman 1961-1963 F. B. Brady N. Braverman R. L. Frank P. B. Glassco L. Greenberg T. J. Gressitt J.J. Kishel W. A. Martin, Jr. C. J. Mundo J. S. Prichard P. E. Ricketts W. J. Romer . J. Rosenberg L. M. Sherer J. H. Armstrong G. S. Axelby M. W. Baldw
3、in, Jr. J. M. Barstow S. A. Bowhill J. G. Brainerd J. M. Carroll S. I. Cohn R. I. Cole D. C. Cook F. A. Comerci G. A. Espersen Standards Committee 1962-1963 H. R. MIMNO, Chairman W. MASON, Vice Chairman W. T. WINTRINGHAM, Vice Chairman L. G. CUMMING, Vice Chairman V. M. Graham R. A. Hackbusch P. E.
4、Haggerty C. J. Hirsch L. C. Hobbs H. W. Johnson E. A. Keller I. M. Kerney J. G. Kreer, Jr. E. R. Kretz mer R. L. Mattingly D. E. Maxwell P. Mertz . I. Metz S. M. Morrison J. H. Mulligan, Jr. D. E. Noble C. D. Owens C. H. Page R. H. Rediker J. B. Russell CM. Ryerson W. A. Shipman H. R. Terhune Consul
5、tants J. Avins A. G. Jensen W. R. Bennett G. A. Morton A. G. Clavier P. A. Redhead A. B. Glenn R. Serrell Coordinators D. E. NOBLE, Standards Coordinator W. MASON, Measurements Coordinator W. T. WINTRINGHAM, Definitions Coordinator * Approved by the IRE Standards Committee, October 18, 1962. Reprint
6、s of this Standard (62 IRE 12. SI) may be purchased while available from the Institute of Electrical and Electronics Engineers, Box A, Lenox Hill Station, . Y., at $0.50 per copy. A 20 per cent discount will be allowed for 100 or more copies mailed to one address. 4 Accelerometer. A device used to s
7、ense the total non-gravitational force per unit mass. Note: In its simplest form, an Accelerometer con sists of a case mounted spring and mass arrangement where displacement of the mass from its rest position relative to the case is proportional to the total non-gravitational acceleration experience
8、d along the in struments sensitive axes. Accelerometers may be con structed to perform a single or double integration within the device. Alignment. In inertial navigation equipment, the orien tation of the measuring axes of the inertial components with respect to the coordinate system in which the e
9、quip ment is used. Note: Initial alignment refers to the result of the process of bringing the measuring axes into a desired orientation with respect to the coordinate system in which the equipment is used, prior to departure. The initial alignment can be refined by the use of non-inertial sensors w
10、hile in operational use. Alignment, Gyrocompass. See Gyrocompass Alignment. Analytic Inertial Navigation Equipment. That class of Inertial Navigation Equipment in which geographic nav igational quantities are obtained by means of computa tions (generally automatic) based upon the outputs of Accelero
11、meters whose orientations are maintained fixed with respect to Inertial Space. Apparent (Dynamic) Vertical. The direction of the vector sum of the gravitational and all other accelerations. Astro-Inertial Navigation Equipment. See Celestial Iner tial Navigation Equipment. Autonavigator, Inertial. In
12、ertial Navigation Equipment which includes means for coupling the output naviga tional quantities derived from the Inertial Navigation Equipment to the navigational control system (autopilot and/or human pilot) of the vehicle. Celestial Inertial Navigation Equipment. That class of Hybrid Inertial Na
13、vigation Equipment in which naviga tional quantities are determined by the direct measure ment of the angular orientation of the local vertical with respect to a celestially fixed coordinate system. Coriolis Correction. In inertial navigation equipment an acceleration term which must be applied to m
14、easurements of acceleration with respect to a coordinate system in translation to correct for the effect of any angular motion of the coordinate system with respect to Inertial Space. Correction, Coriolis. See Coriolis Correction. Doppler Inertial Navigation Equipment. That class of Hybrid Inertial
15、Navigation Equipment which employs redundant velocity information from a Doppler naviga tion radar. Drift, G. See G Drift. Drift, G2. See G2 Drift. Drift, Kinematic. See Misalignment Drift. Dynamic Vertical. See Apparent Vertical. Erection, Platform. See Platform Erection. Free Azimuth Inertial Navi
16、gation Equipment. See Semi-Analytic Inertial Navigation Equipment. Freedom, Single-Degree. See Single-Degree-Freedom-Gyro. Freedom, Two-Degree. See Two-Degree-Freedom Gyro. G Drift. A drift component in Gyros (sometimes in Accel erometers) proportional to the acceleration and caused by-torques resul
17、ting from mass unbalance. G2 Drift. A drift component in Gyros (sometimes in Accel erometers) proportional to the square of the acceleration and caused by anisoelasticity of the rotor supports. Geocentric Latitude. The acute angle between a) a line joining a point with the earths geometric center an
18、d b) the earths equatorial plane. Note: Geocentric Latitude is derived from the Geo graphic Latitude by correcting for the earths deviation from true spherical shape and other anomalies. Geocentric Longitude. The same as Geographic Longit ude. Geocentric Vertical. See Geometric Vertical. Geographic
19、Latitude. The angle between the plumb-bob vertical and the earths equatorial plane. Note: This is generally used in the preparation of maps and charts. (See Geocentric Latitude.) Geographic (Map) Vertical. The direction of a line normal to the surface of the geoid. Geoid. The shape of the earth as d
20、efined by the hypo thetical extension of mean sea level continuously through all land masses. Note: The resulting shape is an ellipsoid of revolu tion. Geometric Inertial Navigation Equipment. That class of Inertial Navigation Equipment in which the geographic navigational quantities are obtained by
21、 computations (generally automatic) based upon the outputs of Acceler ometers whose vertical axes are maintained parallel to the local vertical, and whose azimuthal orientations are main tained in Alignment with a predetermined geographic direction (e.g., north). Geometric (Geocentric) Vertical. The
22、 direction of the ra dius vector drawn from the center of the earth through the location of the observer. 5 Gravity Vertical. See Mass Attraction Vertical. accelerometer bias imposed on the system before de parture. Note: The initial data may be refined after departure on the basis of data derived f
23、rom noninertial sensors as in Hybrid inertial navigation equipment. Kinematic Drift. See Misalignment Drift. Latitude, Geocentric. See Geocentric Latitude. Latitude, Pseudo-. See Pseudo-Latitude. Level, Local. See Local Level. Leveling. See Platform Erection. Local Level. The plane normal to the loc
24、al vertical. Local Vertical. A reference direction, used in defining and establishing the Local Level. Note: It may be plumb-bob, geographic or Mass-Attraction Vertical. Longitude, Geocentric. See Geocentric Longitude. Longitude, Pseudo-. See Pseudo-Longitude. Map Vertical. See Geographic I ertical.
25、 Mass-Attraction Vertical. The normal to any surface of constant geopotential. Note: On the earth this vertical is a function only of the distribution of the mass and is unaffected by forces resulting from the motions of the earth (example direction of a plumb-bob on a nonrotating earth). Misalignme
26、nt Drift. In Gyros, that part of the total apparent drift component due to uncertainty of orienta tion of the Gyro input axis with respect to the coordinate system in which the Gyro is being used. Pitch Angle. See Pitch Attitude. Pitch Attitude. The angle between the longitudinal axis of the vehicle
27、 and the horizontal. Platform Erection. In the Alignment of inertial systems, the process of bringing the vertical axis of a Stable Plat form system into agreement with the local vertical. Platform, Stable. See Stable Platform. Plumb-Bob Vertical. The direction indicated by a simple, ideal, friction
28、less pendulum that is motionless with re spect to the earth. Note: It indicates the direction of the vector sum of the gravitational and centrifugal accelerations of the earth at the location of the observer. Pseudo-Latitude. A latitude in a coordinate system, which system has been arbitrarily displ
29、aced from the earths conventional latitude system so as to move the meridian convergence zone (polar region) away from the place of intended operation. Gyrocompass Alignment. In inertial systems, a process of self-alignment in azimuth based upon measurement of Misalignment Drift about the nominal “e
30、ast-west“ axis of the system. Gyrocompassing. See Gyrocompass Alignment. Gyro (Gyroscope). In inertial navigation, a device using angular momentum (usually of a spinning rotor) to estab lish a frame of reference in Inertial Space. Hybrid Inertial Navigation Equipment. Inertial naviga tion equipment
31、which employs noninertial sensors to reset the equipment while in operational use. Note: Examples of the resets are a positional correc tion, velocity correction, heading correction, gyro bias reset or a combination of these. Inertial Autonavigator. See Autonavigator, Inertial. Inertial Navigation E
32、quipment. A type of dead reckoning navigation equipment whose operation is based upon the measurement of accelerations. Note: Accelerations are sensed dynamically by de vices stabilized with respect to the Inertial Space, and the navigational quantities, such as vehicle velocity, angular orientation
33、 or positional information are deter mined by computers and/or other instrumentation. Inertial Navigation Equipment, Analytic. See Analytic Inertial Navigation Equipment. Inertial Navigation Equipment, Astro-. See Celestial Iner tial Navigation Equipment. Inertial Navigation Equipment, Celestial. Se
34、e Celestial Inertial Navigation Equipment. Inertial Navigation Equipment, Doppler. See Doppler Inertial Navigation Equipment. Inertial Navigation Equipment, Free Azimuth. See Free Azimuth Inertial Navigation Equipment. Inertial Navigation Equipment, Geometric. See Geometric Inertial Navigation Equip
35、ment. Inertial Navigation Equipment, Hybrid (Combined). See Hybrid (Combined) Inertial Navigation Equipment. Inertial Navigation Equipment, Semi-Analytic. See Semi-Analytic Inertial Navigation Equipment. Inertial Navigation Equipment, Strapped-Down (Gimbal-Less) See Strapped-Down (Gimbal-Less) Inert
36、ial Naviga tion Equipment. Inertial Space. A coordinate system or frame of reference defined with respect to the “fixed“ stars. Initial Conditions. In inertial navigation, the initial values of position, velocity, level, azimuth, gyro bias, and 6 Pseudo-Longitude. A longitude in a coordinate system,
37、 which system has been arbitrarily displaced from the earths conventional longitude system so as to move the meridian convergence zone (polar region) away from the place of intended operation. Rate, Torquing. See Torquing Rate. Schiiler Tuning. In the design of Inertial Navigation equipment, the app
38、lication of parameter values such that accelerations do not deflect the platform system from any vertical to which it may have been set. Note: A Schler Tuned system, if fixed to the mean surface of a non-rotating earth, exhibits a natural period of 84.4 minutes. Semi-Analytic Inertial Navigation Equ
39、ipment. The same as Geometric Inertial Navigation Equipment except that the horizontal measuring axes are not maintained in Alignment with a geographic direction. Note: The azimuthal orientations are automatically computed. Single-Degree-Freedom Gyro. A Gyro in which the rotor is free to precess (re
40、lative to the case) about only the axis orthogonal to the rotor spin axis. Space, Inertial. See Inertial Space. Stable Platform. A gimbal-mounted platform, usually containing Gyros and Accelerometers, whose purpose is to maintain a desired orientation in Inertial Space inde pendent of the motion of
41、the vehicle. Strapped-Down (Gimbal-Less)Inertial Navigation Equip ment. Inertial Navigation Equipment wherein the inertial devices (Gyros and Accelerometers) are attached directly to the carrier, eliminating the Stable Platform and gimbal system. Note: In this equipment a computer utilizes Gyro info
42、rmation to resolve the accelerations that are sensed along the carrier axes, and to refer these accelerations to an inertial frame of reference. Navigation is then accomplished in the same manner as in system using a Stable Platform. Torquing Rate. In inertial navigation equipment, the an gular rate
43、 at which the orientation of a Gyro, with respect to Inertial Space, is changed in response to a command. Tuning, Schiiler. See Schiller Tuning. Two-Degree-Freedom Gyro. A Gyro in which the rotor axis is free to move in any direction. Vertical, Apparent (Dynamic). See Apparent (Dynamic) Vertical. Ve
44、rtical, Dynamic. See Apparent Vertical. Vertical,Geographic (Map).SeeGeographic (Map) Vertical. Vertical, Geocentric. See Geometric Vertical. Vertical, Geometric (Geocentric). See Geometric (Geo centric) Vertical. Vertical, Gravity. See Mass Attraction Vertical. Vertical, Plumb-Bob. See Plumb-Bob Vertical. Vertical, Map. See Geographic Vertical. Vertical, Mass Attraction. See Mass Attraction Vertical.
