Abstract: The invention is directed to an angle-measuring instrument such as a theodolite, tacheometer or the like having a coarse-fine drive arrangement for presetting a circle part of a graduated circle to a predetermined read-out value. In a preferred embodiment, a coaxial coarse-fine drive arrangement is actuated by a single control knob which is part of an adjustable drive which can be operated in two positions. In the first position, the adjustable drive functions as a coarse drive and includes a spur gear that meshes with a gear on the carrier of the graduated circle to permit adjusting the circle part to obtain a coarse setting thereof. When the control knob and adjustable drive are moved into the second position, the drive becomes completely disengaged from the carrier and functions as a fine drive that operates on a plane-parallel plate pivotally mounted in the read-out optical transmission path of the instrument to finely adjust the light rays passing therealong.

Abstract: A dual axes multiple prism optical system is disclosed having first and second pairs of 45.degree.-90.degree. prisms mounted on orthogonal substrates operative in one embodiment as an autocollimator and in another embodiment as a directionally sensitive light detector. In both embodiments, the first prism pair provides an azimuthal variation detection capability and the second prism pair provides an elevational variation detection capability. The prisms are so positioned on the substrates that light traveling in a reference direction is incident to the prisms at the critical angle and is totally internally reflected therethrough. Light traveling in a direction which deviates about either the elevational or the azimuthal planes about the reference direction is incident on corresponding ones of the prisms at below the critical angle and is refracted therethrough and collected by an end array matrix of fiberoptic cables mounted to the prisms.

Abstract: An optical system of a theodolite has an altitude angle scale plate having an altitude scale, a horizontal angle scale plate having a horizontal angle scale, a light path combining member for combining the light paths from the two scale plates, a rectangular prism member provided between one of the two scale plates and the light path combining member and having slant faces orthogonal to each other, the light beam from said one of the two scale plates being reflected by the inner surfaces of the orthogonal slant faces of the rectangular prism and thereafter reaching the light path combining member, an objective lens disposed at the exit side of the light path combining member to form the images of the scales on the two scale plates and a focusing screen on which the images of the scales by the objective lens are formed.

Abstract: A method and an arrangement for automatic alignment of a geodetic angle measuring device, especially an electronic tachymeter for topographical survey, in the marking and measuring of points. The object of the invention consists in a rapid and precise, yet constructively and technologically simple solution. The novel feature is the utilization of a reference parameter, which at the device position and the target point is the same. Such reference parameters are the north direction and vertical direction, which are fixed at the target point and the device position by a circular or magnetic compass and pendulum or plumb line. In reference to such north direction and/or vertical direction, there is measured the target direction of a reflector at the target point and are formed the complementary angles by which the tachymeter has to be adjusted so that it can aim at the reflector.

Abstract: Uniquely integrating a search mirror and a deflection mirror with a passive ptical rangefinder and a remote sextant, enhances the operation of both devices. The improved rangefinder/sextant provides day/night 360.degree. azimuthal and at least -5.degree. to about 60.degree. elevational search capability with the additional capability of pointing the search mirror at a navigational star in a direction different from that of an imaging camera. Thus, the imaging camera, can be pointed at the sea horizon that is least obscured by haze and/or sea clutter, thereby allowing altitude readings under adverse conditions.

Abstract: A flight trajectory measuring and observing theodolite wherein the stand portion which essentially comprises a socket element, a stand element, and intermediate element and a leveling stand arranged at the center and the measuring components which essentially contains a yolk element and two housings attached thereto for mounting optical devices, are each constructed as a separate horizontally positionably mountable unit. The stand portion is mounted upon a ring-shaped support element which is non-rotatably connected with the foundation. The connection of the stand portion with the ring-shaped support element is accomplished by means of a foot portion of the leveling stand which is provided at one end with a spherically constructed support surface. Further, the stand portion is radially adjustable and fixable in position in order to horizontally position the stand portion-azimuth rotational axis.

Abstract: The invention relates to an arrangement for determining the vertical axis of a surveying device including a horizontal and a vertical circle each being provided with an index. The two indexes are related to each other and the resulting departure, if any, is measured either visually or physically. By virtue of the inventional arrangement additional means for determining the vertical axis of a surveying device such as inclinometers are eliminated.

Abstract: This invention relates to a multi-purpose surveying instrument, more specifically a composite instrument which can be used as a theodolite, a level surveying instrument, and a plane table, and which provides a precision surveying instrument needed in general architecture, civil engineering and the like.

Abstract: A device for adjusting the azimuthal and inclination directions of a wave reflector, notably for Hertzian waves, comprises a base plate adapted to be secured to a reference surface of the reflector, a cradle rigid with the plate and supporting a pivoting element movable in the adjustment inclination plane through an angle readable in relation to the cradle. This movable inclination element supports another element rotatably mounted about an axis perpendicular to the inclination pivoting axis, and constituting an element movable in the azimuthal direction through an angle readable in relation to the inclination movable element.

Abstract: An angle measuring device comprises a base, a telescope seated thereupon for rotation about an axis, a graduated circle having a line division, a micrometer for subdividing said line division, and photoelectric scanners for detecting angular values from said line division and from said micrometer. A graduated plate provided with a reticle is located in said telescope. Said reticle has a zone limited by two line marks which are arranged in parallel and symmetrically to and on either side of one of the reticle lines. Said two lines are spaced from said reticle line by a width which is at least double the size of one division interval of the graduated circle line division.

Abstract: A system for fully characterizing monochromatic radiation incident on the stem. The system computes the azimuth and elevation of the point of origin, optical frequency, pulse width, power level and pulse repetition frequency of the source.

Abstract: The angle measuring system comprises: a first mirror rigidly attached to muzzle end of a long gun barrel in a plane normal to the bore axis; second and third mirrors mounted on the gun mount near each other at the rear end of the barrel facing outwardly at 45.degree. to the bore axis; and a collimated light source positioned to project a primary light ray onto the second mirror at a 45.degree. angle to be reflected to the first mirror and then reflected back to the third mirror. A set of mirrors is mounted in the path of the ray reflected from the third mirror, to split the primary ray into two separate substantially-parallel component rays having vertical components of transverse motion corresponding respectively to the vertical and horizontal components of angular motion of the gun muzzle and first mirror.

Abstract: A light emitting diode is located beneath a glass scale carrier, one for each scale (azimuth and elevation), emitting essentially monochromatic light, which penetrates through the glass scale; the scale is observed through an optical system. The optical system for viewing of the scale is located on a carrier secured in the telescope housing; the light emitting diodes are powered by a battery secured in the housing, which energizes a timer, such as R/C circuit settable for normal observation times, for example about thirty seconds.