Navigation apparatus

A navigation system operable without a visible horizon is provided. The system can include a collapsible sextant apparatus having a first holder to accommodate a visual spotting scope and a second holder connected to the first holder to accommodate an electronic navigation device. The electronic navigation device can include elevation and timing factors for navigation. The first holder can include a rotatable base extending in a first direction, and a retention element disposed on the rotatable base to retain the visual spotting scope. The second holder can include a longitudinal member to retain the electronic navigation device extending in a second direction substantially perpendicular to the first direction such that the first holder is disposed substantially perpendicular to the second holder and the visual spotting scope and the electronic navigation device can be aligned at a predetermined angle.

BACKGROUND

Field of the Invention

The embodiments herein generally relate to a navigation apparatus, and more particularly to a collapsible sextant apparatus, a sextant apparatus operable without a visible horizon, and an electronic horizonless sextant system.

Background of the Invention

Generally, a sextant is a doubly reflecting navigation instrument used to measure the angle between two visible objects. The sextant is conventionally used to determine an angle between an astronomical object and the horizon for the purposes of celestial navigation. Other instruments have also been used to determine the angle between astronomical objects and the horizon for the purposes of celestial navigation. Two or more observations of different celestial bodies can be used to estimate a navigator's position. When the horizon is not visible, an artificial horizon or electronic sextant can be used to estimate a navigator's position.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, an embodiment herein provides a collapsible sextant apparatus. The apparatus includes a first holder configured to accommodate a visual spotting scope, a second holder connected to the first holder and configured to accommodate an electronic navigation device comprising elevation and timing factors for navigation. The first holder includes a rotatable base extending in a first direction, and a retention element disposed on the rotatable base configured to retain the visual spotting scope. The second holder comprises a longitudinal member extending in a second direction substantially perpendicular to the first direction, wherein the first holder and the second holder are positioned substantially perpendicular to one another.

In the embodiment, the retention element can include a plurality of rotatable arms extending from the rotatable base. The plurality of rotatable arms can rotate with respect to the rotatable base, and the rotatable base can rotate with respect to the second holder. In the embodiment, the second holder can include a side wall abutting the first holder and an adjustable clamp operatively connected to the longitudinal member, where the longitudinal member can extend from the side wall, and the adjustable clamp can slide along the longitudinal member.

The apparatus of the embodiment can further include at least one retaining mechanism operable to secure the electronic navigation device to the second holder. The apparatus of the embodiment can further include a damping element disposed on the first holder configured to grip the visual spotting scope.

In the embodiment, the electronic navigation device can be any of a smartphone and a computer tablet. The rotatable base of the first holder can include a first back surface. The second holder can include a second back surface. The first back surface can be positioned substantially planar to the second back surface in a stowed configuration.

The apparatus of the embodiment can further include a latch element configured to lock the first holder in a plurality of predetermined angles with respect to the second holder.

Another embodiment provides a sextant apparatus operable without a visible horizon. The apparatus includes a first holder configured to releasably clamp a visual spotting scope along an optical axis; and a second holder configured to releasably clamp an electronic navigation device comprising a tilt sensor, a clock, and a geomagnetic compass. The tilt sensor includes a tilt axis, and the first holder is operatively connected to the second holder to dispose the tilt axis at an adjustable angle with respect to the optical axis.

In the embodiment, the first holder can be operatively connected to the second holder to dispose the tilt axis parallel to the optical axis in a first arrangement.

The sextant apparatus operable without a visible horizon of the embodiment can further include a first clamp disposed on the first holder configured to elastically clamp the visual spotting scope aligned along the optical axis; and a second clamp disposed on the second holder configured to elastically clamp the electronic navigation device with the tilt axis at the adjustable angle with respect to the optical axis.

In the embodiment, the first holder can include an upwardly open cradle configured to house the visual spotting scope. The upwardly open cradle can include a base and a plurality of arms extending upward from the base. The second holder can include a slidable clamp configured to urge the electronic navigation device against a sidewall of the second holder in a first direction toward the first holder and clamp the electronic navigation device in a second direction perpendicular to the first direction, while leaving the electronic navigation device unconstrained in a third direction perpendicular to the first and second directions.

Another embodiment provides an electronic horizonless sextant system. The system includes a visual spotting scope disposed on a firearm and comprising an optical axis, an electronic navigation device comprising a tilt sensor, a clock, and a geomagnetic compass, and a first detachable holder comprising a longitudinal axis. The first detachable holder is configured to operatively connect to the firearm and configured to accommodate the electronic navigation device. The optical axis and the longitudinal axis are disposed substantially perpendicular to one another. The visual spotting scope is removably disposed on the firearm, and the electronic navigation device is removably disposed in the first detachable holder.

The system can further include an external tilt sensor disposed on the visual spotting scope. The system can further include a processor configured to receive a first input signal of direction and a first tilt from the tilt sensor, a second input signal of a second tilt from the external tilt sensor, and a third input signal of a celestial body selection visible through the visual spotting scope at time of first and second input signals, and the processor can output a geospatial position based on the first, second, and third input signals.

The system can further include an external tilt sensor and a second detachable holder configured to operatively connect to the firearm and configured to accommodate the external tilt sensor. The second detachable holder and the first detachable holder can be disposed at a predetermined angle with respect to one another, and the tilt sensor can be removably disposed in the second detachable holder.

The system can further include a processor configured to receive a first input signal of direction and a first tilt from the tilt sensor, a second input signal of a second tilt from the external tilt sensor, and a third input signal of a celestial body selection visible through the visual spotting scope at time of first and second input signals, and the processor can output a geospatial position based on the first, second, and third input signals.

In the embodiment, the first holder can include a slidable clamp configured to urge the electronic navigation device against a sidewall of the first holder in a first direction relative to the firearm and clamp the electronic navigation device in a second direction perpendicular to the first direction, while leaving the electronic navigation device unconstrained in a third direction perpendicular to the first and second directions.

DETAILED DESCRIPTION OF THE INVENTION

It will be understood that when an element or layer is referred to as being “on”, “connected to”, or “coupled to” another element or layer, it can be directly on, directly connected to, or directly coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element or layer is referred to as being “directly on”, “directly connected to”, or “directly coupled to” another element or layer, there are no intervening elements or layers present. It will be understood that for the purposes of this disclosure, “at least one of X, Y, and Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XYY, YZ, ZZ).

In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Referring now to the drawings, and more particularly toFIGS. 1A through 3B, where similar reference characters denote corresponding features consistently throughout the figures, there are shown exemplary embodiments.

Embodiments herein provide a celestial navigation device. The celestial navigation device, referred to herein as a sextant apparatus, can identify a position update, that is, a geospatial location. The sextant apparatus can provide several configurations for mounting and angle measurements. For example, the sextant apparatus according to embodiments herein, can be disposed on Picatinny rails (MIL-STD-1913) on rifles, and, for example, the sextant apparatus can be provided in a standalone configuration.

The Picatinny rail, or tactical rail, is a bracket on some firearms that provides a standard mounting platform consisting of rails with multiple transverse slots. The Picatinny rails can mount heavy sights of various kinds, a variety of accessories and attachments, and can be disposed on the rear upper surface (receiver) of long arms, may be either fitted to or machine milled into the upper, side, or lower surfaces of all manner of weapons from crossbows to pistols and long arms, up to and including anti-materiel rifles. Examples of accessories that may be selectively mated to a Picatinny rail include: vertical fore grips, bipods and rests, electro-optical sights, image intensifiers, flashlights, laser designators, and the like. Such accessories may be rapidly mounted to and dismounted from the rail, thus providing an accurate and repeatable quick detachable mounting platform. By way of example, telescopic scopes that are mounted, zeroed, dismounted, and remounted to a Picatinny rail are known to maintain the aforementioned zero within acceptable tolerances. Embodiments of the disclosed sextant apparatus take advantage of the robust and repeatable mount of the Picatinny rail system and may include components configured to attach thereto.

Traditional celestial navigation requires measuring the elevation angle of a celestial object such as a star, planet, sun, moon, and the like or a combination thereof, above the horizon. An accurate time estimate to within a few seconds is required along with a rough estimate of position, and tabulated positions of celestial objects. Some smartphone applications can provide celestial navigation readings by sighting to celestial objects through an aperture of the smartphone with an elevation angle reading taken from an internal tilt sensor, a time reading from an internal clock, along with locally or remotely stored tabulated positions of the celestial objects. Without needing to view the horizon, position updates are possible as long as a celestial object is detectable visually.

Embodiments herein can also utilize input from external tilt sensors to provide more accurate elevation angle measurements.

The embodiments herein provide a sextant apparatus that does not require a visible horizon in order to estimate a user position. Further, the sextant apparatus of the embodiments accommodates various smartphone form factors and can incorporate external sensor elevation angle measurements. As such, a user can determine a rapid, nearly instantaneous, geospatial location update with minimal a priori knowledge of traditional sextant instrumentation operation, including minimal a priori knowledge of constellations or other celestial objects.

When operating in contested GPS signal environments, embodiments of the sextant apparatus herein can provide a robust navigation option. Referring now to the drawings, and more particularly toFIGS. 1A through 3B, where similar reference characters denote corresponding features consistently throughout the figures, there are shown exemplary embodiments.

FIG. 1Ais a schematic illustration of a sextant apparatus100according to an embodiment herein.FIG. 1Bis a schematic illustration of a collapsible sextant apparatus100ain a folded configuration according to an embodiment herein. The collapsible sextant apparatus100aofFIG. 1Bcan be unfolded and deployed in a configuration illustrated by the sextant apparatus100ofFIG. 1A.

The sextant apparatus100can include a first holder114to accommodate a visual spotting scope208. The first holder114can include a base118and a retention element122disposed on the base118. The retention element122can retain the visual spotting scope208on the base118of the first holder114.

The sextant apparatus100can include a second holder126connected to the first holder114. The second holder126can accommodate an electronic navigation device204, such as a communication device, for example, a smartphone, computer tablet, and the like that can deliver appropriate elevation and timing factors for navigation. The electronic navigation device204can include a compass, tilt sensor, celestial chart, such as a navigation almanac, stored on a hardware device, and a clock. The stored celestial chart can be in the form of data and stored locally to the electronic navigation device or remotely, for example, accessible via a cellular connection. The first holder114and the second holder126can be positioned perpendicular to one another. For example, the base118of the first holder114can extend in a Y direction and the second holder126can have a longitudinal member154that can extend in an X direction perpendicular to the Y direction. In such an example, the electronic navigation device204can be disposed substantially in an XZ plane in the second holder126and the visual spotting scope208can have an optical axis178extending substantially in the Y direction when the visual spotting scope208is disposed in the first holder114, where X, Y, and Z directions are orthogonal to one another. In other words, the base118can extend in the Y direction and the longitudinal member154can extend in the X direction perpendicular to the base118.

The retention element122can be configured as a plurality of arms extending from the base118. Alternatively, the retention element122can be configured as an interference-fit thermoplastic polyurethane (TPU) cradle, a yoke vise, a quick detach protuberance affixed to scope rings, fixed scope rings having cam-locking halves, and the like, or combinations thereof.

In some embodiments, the second holder126can include a side wall150abutting the first holder114, and the longitudinal member154extending from the side wall150. An adjustable clamp158can be operatively connected to the longitudinal member154. The adjustable clamp158can slide along the longitudinal member154to hold the electronic navigation device204.

A retaining mechanism162, such as a set screw, can be disposed in the adjustable clamp158. Rotation of the retaining mechanism162can selectively permit or halt movement of the adjustable clamp158with respect to the longitudinal member154, thus securing the electronic navigation device204to the second holder126. A slide element164can provide stability for the adjustable clamp158as the adjustable clamp158moves along the longitudinal member154. For example, the slide element164can be configured as a ratchet having intermeshing teeth with the adjustable clamp158, or the slide element164can be configured as a foam rubber, smooth plastic, and the like to provide stable motion between the adjustable clamp158and the longitudinal member154.

A damping element166can be disposed on the first holder114to provide a secure grip between the first holder114and the visual spotting scope208, and dampen; i.e., absorb or suppress vibration of the visual spotting scope208. The damping element166can include a soft spongey material, such as a closed cell polyurethane foam, a foam rubber, woven or non-woven textile, and the like. The damping element166can be bonded to the base118, bonded to the retention element122, or bonded to the base118and the retention element122with an adhesive or glue. The damping element166can also dampen out vibrations in the sextant apparatus100, the first and second holders114,126and the visual spotting scope208.

In some embodiments, the sextant apparatus100can include a three-dimension (3-D) printed first and second holders114,126that can accommodate several different sized visual spotting scopes208for sighting celestial objects and electronic navigation devices204for determining geospatial position. For example, the sextant apparatus100can be a lightweight 3-D printed resin material structure.

In some embodiments, the sextant apparatus100acan be collapsible, as indicated inFIG. 1B. The collapsible sextant apparatus100acan include a first holder114ato accommodate a visual spotting scope208. The first holder114acan include a rotatable base118aand a retention element122adisposed on the rotatable base118a. The retention element122acan retain the visual spotting scope208on the rotatable base118aof the first holder114a.

The collapsible sextant apparatus100acan include a second holder126aconnected to the first holder114a. The second holder126acan be configured to accommodate an electronic navigation device204. In a deployed arrangement, the first holder114aand the second holder126a(illustrated with dashed lines) can be positioned perpendicular to one another. In a folded or stowed arrangement, the first holder114aand the second holder126acan be positioned parallel to one another as illustrated inFIG. 1B. The first holder114aand the second holder126aare rotatable relative to one another, for example, the second holder126ais shown as pivoted inFIG. 1Bwhile the first holder114aremains stationary by dashed arrow “C” about rotation axis “A”, but the same folded configuration can be achieved by the second holder126aremaining stationary and the first holder114apivoting in an opposite direction. A contour surface146can stop rotation of the first holder114arelative to the second holder126aand a latch element148can be operable to lock the first holder114arelative to the second holder126ain a deployed arrangement, a stowed arrangement, or at a predetermined folded position between the deployed and stowed arrangements.

The rotatable base118aof the first holder114acan include a first back surface170, and the second holder126acan include a second back surface174. The first back surface170can be positioned in a substantially planar direction planar to the second back surface174in the stowed configuration.

The retention element122acan be configured as a plurality of rotatable arms extending from the rotatable base118a. Alternatively, the retention element122acan be configured as an interference-fit TPU cradle, a yoke vise, a quick detach protuberance affixed to scope rings, fixed scope rings having cam-locking halves, and the like, or combinations thereof. The rotatable retention elements122acan rotate with respect to the rotatable base118a, and the rotatable base118arotates with respect to the second holder126a. In the stowed arrangement, the retention elements122aof the collapsible sextant apparatus100acan be folded as indicated by arrows “D” to the rotatable base118ato provide a flat configuration for storage, such as in a pocket for convenient transportation, mobility, and accessibility.

In some embodiments, the second holder126acan include a side wall150abutting the first holder114a, and a longitudinal member154extending from the side wall150. An adjustable clamp158can be operatively connected to the longitudinal member154. The adjustable clamp158can slide along the longitudinal member154to hold the electronic navigation device204.

Similar to the embodiment shown inFIG. 1A, a retaining mechanism162, such as a set screw, can be disposed in the adjustable clamp158in the sextant apparatus100aofFIG. 1B. Rotation of the retaining mechanism162can selectively permit or halt movement of the adjustable clamp158with respect to the longitudinal member154, thus securing the electronic navigation device204to the second holder126a. Again, the slide element164can provide stability for the adjustable clamp158as the adjustable clamp158moves along the longitudinal member154. For example, the slide element164can be a ratchet having intermeshing teeth with the adjustable clamp158, or the slide element164can be a foam rubber, smooth plastic, and the like to provide stable motion between the adjustable clamp158and the longitudinal member154.

A damping element166(not shown in the collapsed view ofFIG. 1B) can be disposed on the first holder114ato provide a secure grip between the first holder114aand the visual spotting scope208, and dampen; i.e., absorb or suppress vibration of the visual spotting scope208. The damping element166can be bonded to the rotatable base118a, bonded to the retention element122a, or bonded to the rotatable base118aand the retention element122awith an adhesive or glue. The damping element166can also dampen out vibrations in the sextant apparatus100a, the first and second holders114a,126aand the visual spotting scope208.

FIG. 2A, with reference toFIGS. 1A and 1B, is a schematic illustration of a sextant system200including an electronic navigation device204that can deliver appropriate elevation and timing factors for navigation and a visual spotting scope208according to an embodiment herein. As used herein, the electronic navigation device204that can deliver appropriate elevation and timing factors for navigation may also be referred to as a communication device, and an electronic navigation device such as a smartphone, a tablet computer and the like. Those skilled in the art will appreciate that this terminology is only illustrative and does not affect the scope of the invention.FIG. 2B, with reference toFIGS. 1A through 2A, is a schematic illustration of a sextant system200aaccording to another embodiment herein.

As shown inFIGS. 2A and 2B, the embodiments herein further provide a sextant system200,200athat can operate without a visible horizon or an artificial horizon. The sextant system200,200acan include a sextant apparatus100,100a. The sextant apparatus100,100acan include a first holder114,114aconfigured to releasably clamp a visual spotting scope208along an optical axis178and a second holder126,126ato releasably clamp an electronic navigation device204. The electronic navigation device204can include a tilt sensor, a clock, and a geomagnetic compass. The tilt sensor can have a tilt axis206. The tilt axis206can register zero tilt angle when the tilt axis206is pointed from a geospatial location to the horizon. The tilt axis206can register zero tilt in this configuration whether the horizon is visible or not.

The first holder114,114acan be operatively connected to the second holder126,126ato dispose the tilt axis206at an adjustable angle to the optical axis178. When the tilt axis206is aligned with the optical axis178, the tilt axis206can register the angle from the horizon to a celestial body when the celestial body is sighted through the visual spotting scope208. It will be recognized by one of ordinary skill in the art that elements of the disclosed invention may provide an adjustable structure for orienting the spotting scope208, electronic navigation device204, or other elements with respect to each other. However, it will be further recognized that once the sextant system200,200ais calibrated, it is desirable to maintain a rigid attachment of the various elements. Any relative motion between, by way of example, the spotting scope208and navigation device204, after calibration, will degrade the accuracy of the sextant system200,200a.

In some of these embodiments, the first holder114,114acan be operatively connected to the second holder126,126ato dispose the tilt axis206parallel to the optical axis178in a first arrangement. Also, the first holder114,114acan be operatively connected to the second holder126,126ato dispose the tilt axis206perpendicular to the optical axis178in a second arrangement.

In some embodiments, the first holder114,114acan include a resilient retainer212to elastically clamp the visual spotting scope208aligned to the first holder114,114aalong the optical axis178. The second holder126,126acan include a second clamp216to elastically clamp the electronic navigation device204aligned to the second holder126,126awith the tilt axis206at the adjustable angle to the optical axis178.

The first holder114,114acan include an upwardly open cradle230configured to accept an outer contour of the visual spotting scope208. The upwardly open cradle230can include the base118,118aand a retention element122,122aextending upward from the base118,118a. The retention element122,122acan be a plurality of arms. The second holder126,126acan include the adjustable clamp158to urge a planar shape of the electronic navigation device204against the side wall150in a first direction L1toward the first holder114,114aand clamp the planar shape of the electronic navigation device204in a second direction L2perpendicular to the first direction L1, while leaving the planar shape unconstrained in a third direction L3perpendicular to the first and second directions L1, L2.

While the adjustable clamp158is described as sliding toward the first holder114,114ato urge a planar shape of the electronic navigation device204against the side wall150in a first direction L1, the embodiments herein are not so limited and it can be understood that the positions of the side wall150and adjustable clamp158can be interchanged so that the adjustable clamp158can be described as sliding away from the first holder114,114ato urge a planar shape of the electronic navigation device204against the side wall150in a negative first direction −L1.

FIG. 3A, with reference toFIGS. 1A through 2B, is a schematic illustration of an electronic horizonless sextant system200baccording to another embodiment herein. The electronic horizonless sextant system200bcan include an electronic navigation device204, such as a smartphone, computer tablet, and the like, a visual spotting scope208, and an external tilt sensor320.FIG. 3B, with reference toFIGS. 1A through 3A, is a schematic illustration of a top view of the electronic horizonless sextant system200bofFIG. 3Aaccording to an embodiment herein.

The electronic horizonless sextant system200bcan include a visual spotting scope208disposed on a firearm304and having an optical axis178, and an electronic navigation device204having a tilt sensor, a clock, and a geomagnetic compass. The electronic horizonless sextant system200bcan include a first detachable holder126bto operatively connect to the firearm304and to accommodate the electronic navigation device204.

In some embodiments, the optical axis178of the visual spotting scope208disposed on the firearm304and the first detachable holder126bcan be disposed perpendicular to one another. For example, the optical axis178can extend in a Y direction and the detachable holder126bcan have a longitudinal member154that extends along a longitudinal axis306of the detachable holder126bin an X direction perpendicular to the Y direction. In such an example, the electronic navigation device204can be disposed substantially in an XZ plane in the detachable holder126band the visual spotting scope208can have an optical axis178extending substantially in the Y direction when the visual spotting scope is disposed on the firearm304, where X, Y, and Z directions are orthogonal. In other words, the optical axis178and the longitudinal axis306can be disposed perpendicular to one another.

In some embodiments, the visual spotting scope208can be removably disposed on the firearm304, and the electronic navigation device204can be removably disposed in a first detachable holder126b. The visual spotting scope208can be removably disposed on the firearm304as described above for the visual spotting scope208removably disposed in the first holder114,114a. The electronic navigation device204can be removably disposed in the first detachable holder126bas described above for the electronic navigation device204disposed in the second holder126,126a.

For example, the first detachable holder126bcan include an adjustable clamp158configured to urge a planar shape of the electronic navigation device204against a side wall150in a first direction relative to the firearm304and clamp the planar shape of the electronic navigation device204in a second direction perpendicular to the first direction, while leaving the planar shape unconstrained in a third direction perpendicular to the first and second directions.

In an embodiment, an external tilt sensor can be aligned with the visual spotting scope208optical axis178. For example, the external tilt sensor can be configured as a first external tilt sensor316bonded to the visual spotting scope208or a second external tilt sensor320disposed in a second holder324. The second holder324can be a detachable holder configured to operatively connect to the firearm304and configured to accommodate the second external tilt sensor320. The second tilt sensor320can be removably disposed in the second detachable holder324. In some of these embodiments, the second detachable holder324and the first detachable holder126bcan be disposed at a predetermined angle to one another. Adjustment dials328can be adjusted to accurately align the predetermined angles between the first and second holders126b,324and between either one or both of the first and second holders126b,324and the optical axis178of the visual spotting scope208. In some of these embodiments, the first and second detachable holders126b,324are disposed on Picatinny rails332of the firearm304. All rail-mounted items can be quickly attached and removed from firearm304so as not to impede operation thereof.

The first and second tilt sensors316,320can include a power source such as a battery336and power lines340.

The electronic horizonless sextant system200bcan include at least one of the first and second external tilt sensors316,320. A tilt reading of the external tilt sensor316,320can be compared to a tilt sensor reading of the electronic navigation device204to align the optical axis178of the visual spotting scope208with the tilt sensor of the electronic navigation device204. The external tilt sensor316,320can utilize a wired or wireless link, for example, a Bluetooth® system, to communicate from the spotting scope208to the electronic navigation device204(for example, a smartphone). The measured elevation angle can be copied from a Bluetooth® receiving application and pasted into the celestial navigation application by a processor in the electronic navigation device204. When the electronic navigation device204is separate from the visual spotting scope208, as provided in embodiments herein, mounting requirements can be simplified.

In embodiments, the electronic navigation device204can include a processor or a processor can be separate but communicatively coupled to the electronic navigation device204. The processor can be configured to receive a first input signal of direction and a first tilt from the internal tilt sensor, a second input signal of a second tilt from at least one of the external tilt sensors316,320, and a third input signal of a celestial body selection visible through the visual spotting scope208at the time of the first and second input signals. The processor can output a geospatial position based on the first, second, and third input signals, for example, after repeating the sighting process to at least three separate celestial objects.

The processor can execute computer code stored on hardware using an operating system such as iOS®, Android®, MS Windows®, Linux®, etc. for example, an operating system of a phone to be utilized, with an appropriate celestial navigation application to output the geospatial position.