Abstract: In one embodiment, a reflecting surface, a gnomon and a dial are arranged so that rays from the sun are reflected toward gnomon such that its projected image is visible on dial. The projected image moves across the dial in response to the movement of sun across the sky, thus providing some indication of time and season. Other embodiments are described and shown.

Abstract: Sundial apparatus with overlying barrier grid.

Abstract: The most accurate method of finding the true north is through astronomical observations, for example, by observing the position of the sun. However, the procedure is complicated. The instantaneous position of the sun must be calculated from astronomical data for each instance of observation, and the operator must wait for the predetermined time to come. Elaborate manual adjustments are required. The present invention discloses an automatic solar compass comprising a cylindrical omni-directional lens, a detection means, and a servomechanism. It is as easy to use as the magnetic compass, but much more accurate and reliable than the magnetic compass.

Abstract: Sundials and solar compasses including are disclosed. Some embodiments include an omni-directional lens, which can focus a sun beam into a sharp spot with a long depth of field. By projecting the spot onto a cylindrical panel, both the day of the year and the time of the day can be read off simultaneously with very high accuracy. Because of the simultaneous displaying of time and date, no equation-of-time correction is required. If the time is known, the true north can be determined with high accuracy, and the device becomes a reliable and easy-to-use solar compass.

Abstract: To date, the existing sundials and solar compasses use a gnomon, such as a stylet, to project a shadow under the sun on a marked surface to find the time or the true north. Because of the fussiness of the shadow and the dependence of the position of the sun with the day of the year (equation of time), the accuracy is low. The present invention discloses an omni-directional lens, which can focus the sun beam into a sharp spot with a long depth of field. By projecting the spot on a cylindrical panel, both the day of the year and the time of the day can be read off simultaneously with very high accuracy. Because of the simultaneous displaying of time and date, no equation-of-time correction is required. If the time is known, the true north can be determined with high accuracy, and the device becomes a reliable and easy-to-use solar compass.

Abstract: A system and method for navigation utilizing sources of pulsed celestial radiation are provided. A spacecraft, satellite, or other vehicle (12) has a pulse sensor (22) mounted thereto for detecting signal pulses (14) generated by a plurality of pulsars or other celestial objects (16). The detected signal pulses (14) are synchronously averaged at the known period of the pulsar or other celestial object (16) with respect to a timer (24). Timer (24) measures the pulse time of arrival at the pulse sensor (22) by comparing the pulse signal (14) with a pulse shape template (52), and a processing means (30) calculates the offset time between the measured pulse time of arrival at sensor (22) with a calculated pulse time of arrival at the solar system barycenter (SSBC).

Abstract: A solar counter to provide an accurate way of measuring the middle of the night or another selected fraction of the day or night. The solar counter activates an electronic event when it has finished counting down. For example, a lamp can be turned off half way through the dark part of the night. This process is extremely accurate, and adaptations of this concept can be used in the safety industry, irrigation, or in agriculture. One embodiment of this concept has a battery back-up circuit, but a substitute 50/60 Hz clock input frequency in the case of AC power loss can also be provided using an uninterruptible power supply (UPS).

Abstract: A universal timepiece from which a latitude and a longitude can be determined. A bottom plate which has the names of the main cities in the world, scales and the relative longitudes according to the real longitudes of the cities on the circumference thereof, is included. Comprised is a circular hour plate which has a 24-divisional scale having the same angles with respect to the center. And a circular star plate which rotates 360.99 per 24 hours is included. The rotational axis coincides with the Polaris or the south pole and the main stars and a concentric circle for representing the declination are designated in the star plate. At each concentric circle, the declination or the value obtained by subtracting the declination from 90 is recorded. The clock plate rotates to indicate the time. The star plate is the timepiece which rotates in the same velocity with the actual celestial sphere.

Abstract: A mechanism for determining whether the sun is visible at a diurnal solar event and for mechanically triggering actions based upon the sun being visible during the diurnal solar event is disclosed. The mechanisms of the invention can perform these operations without intervention or supervision for long periods of time. Certain embodiments have been applied to provide a diurnal solar event trigger based upon sidereal noon for a clock providing accurate timing for 10,000 years without intervention or supervision.

Abstract: A space-time tracker for announcing the time and tracking the celestrial bodies on the spot of observation comprises a clock mechanism with clock hands on a dial of 24 hours and a synchronic motor for driving a star atlas and a plurality of planet driving devices which actuate a plurality of annular displays moving around a moon/star ring to periodically show an on spot planet thereon. The space-time tracker also indicates the variations or deviations of the solar calendar and the lunar calendar and the times of different time zones around the world. This disclosure is characterized in automatically and perfectly demonstrating the relationship between the time and space.

Abstract: A compass wherein positional information regarding a predetermined terrestrial location is stored; present time, corresponding to the terrestrial location whose positional information is stored, is measured and displayed; and constellation data is stored. A geomagnetism-detector is provided for detecting the direction of geomagnetism and for deriving azimuthal data therefrom. A constellation data display device is provided for reading out stored constellation data in accordance with the derived azimuthal data, the stored positional information, and the measured present time, and for displaying the readout constellation data.

Abstract: This invention concerns a compass watch as well as a bezel specifically intended to fit out such a watch. The invention comprises at least one time indicating element (4) kinematically driven in rotation by a mechanical or electromechanical horometric movement, and particularly intended to be pointed towards the sun, and direction indicating means (N, S, W, E) arranged on said watch enabling one to know, as a function of the orientation of said indicating means (4), the direction of at least one of the cardinal points, and is characterized in that it includes correction means (52; 16, M) for the positioning of the cardinal points, adapted to take into account the equation of time and to correct any variation between true solar time and the legal or local time of day. The invention is applied to a watch, preferably of the mechanically or electromechanically driven type.

Abstract: A sundial is described using a mirror to reflect an indexing spot of sunlight onto the back of a translucent dial face that is marked with time and date indicia. Adjustments are provided so that a sundial designed for any location can be used in another location and still provide accurate zone time and date.

Abstract: A remote light source responsive time indicator includes a preferably cylindrical body of transparent material with a light receiving and refracting surface on one side and an axial image producing surface on a remaining side. The image producing surface may be formed as a translucent surface on the body, integrated therewith or applied thereto. Angularly spaced axial time indicia is also provided on the image producing side. The body is preferably supported on a base so the light receiving and refracting side faces upwardly and the image producing side faces downwardly. Sunlight received through the light receiving and refracting surface is concentrated optically through the transparent body and an intense visible image of the light is made to appear on the opposite side by provision of the image producing surface. This image moves with the sunlight across the image producing surface and indicates time in hourly increments when associated with the angularly spaced indicia.

Abstract: A sundial with a concave hemispherical body and top surface generally horizontal has longitude displacement, latitude, sun declination, and time indicia originating at the spherical gnomon located at the spherical center of the hemisphere. Site set up is accomplished by plumbing the gnomon over the site latitude and longitude displacement indicia and then rotating on a horizontal surface until the correct time is indicated by the shadow of the gnomon from the sun. Two six-month sundials or two removably attachable inserts are used for indication of watch time for complete years.

Abstract: A solar compass device having a first disc member provided spaced apart time markings indicative of the time of day and disposed in a counterclockwise direction in a circular ring pattern thereon. A second disc member is rotatably displaceable with respect to the first disc member to permit rotational displacement between the first and second disc members with the members disposed in substantially parallel planes. A single fixed indicating marking is provided on the second disc member and aligned with a south end of a north-south radius passing through a center point relative to the ring, and the ring. In operation, the first disc member is oriented with one of the 12 o'clock marking, aligned substantially in the direction of the sun, with the fixed indicating means having been aligned with a marking indicative of approximately the time of day. With the discs so oriented, the north end of the radius is automatically aligned in the direction of the north pole.

Abstract: An instrument for telling time at night includes a base that has a central aperture for sighting on Polaris and an annular hour scale inscribed on the base with the axis of the aperture as the center of the annulus, a calendar scale rotatable on the base about said axis and having indicia adapted to be aligned with the indicia on the hour scale, and a pointer rotatable about said axis and arranged to be removably secured to the calendar scale with its indicating edge in alignment with a selected mark on the calendar scale.

Abstract: A passive solar heating model for studying the daylight illumination of a lot containing buildings and trees comprises a platform, a pair of arms pivotally mounted at one end thereof to the opposite sides of the platform, and an arcuate guide track pivotally mounted to the free ends of the arms for supporting a light source. The pivotal arms allow adjustments to account for the latitude corresponding to the parallel on which the lot is located and the pivotal guide track allows adjustments to accommodate for the time of the year to be studied. Finally, the light source is movably mounted on the track allowing for time-of-the-day adjustments.

Abstract: The disclosure relates to a sundial employing a new type of gnomon comprising an opaque design printed on a plate of transparent material. The sundial described is designed for use in a specific locale, thereby enabling greater accuracy. The design of the casing of the sundial is therefore influenced by the choice of where it is to be used.

Abstract: A sundial is disclosed comprising specularly reflective convex surfaces that form virtual images of the sun in a separate plane or conical surface in which a numbered dial plate is mounted. The axis of revolution of the curved surfaces is mounted parallel to the axis of rotation of the earth and the time scale is also centered about this axis, but in a separate plane or cone located at a distance below the nearest reflective convex surface equal to the radius of said convex surface.

Abstract: A method and apparatus for determining local solar time for virtually any location on any planet having a radiating sun, wherein the method requires minimal a prior knowledge of the planet's major characteristics and the apparatus is organized so as to permit completely automatic determination of the key parameters from which the time calculation is derived. Advantageously, the time determination is accomplished using a formulation of the time equation which depends on two key solid angles initially obtainable any time the planet's sun is reasonably high above the horizon. Additionally, methods are outlined which permit the apparatus to provide basic navigational data, such as latitude and longitude locations (for other than extreme polar positions) of the timepiece.