Abstract: A magazine loader/unloader, designed to stand on a table or be handheld during use, includes a loader/unloader housing, including right and left sides, front and rear sides, and a flat bottom plate; a loading structure, including a loading member; and an unloading structure, including top and bottom guides, and an unloading protrusion. Also disclosed is a method of using the magazine loader/unloader, including positioning cartridge, loading cartridge, and unloading cartridge.

Abstract: A firearm tracking system to locate missing firearms. The firearm tracking system includes a firearm, having a body with a chamber designed to hold a plurality of bullets, a barrel designed to fire each bullet, and a trigger in communication with the chamber and barrel. A GPS unit is removably secured within the body of the firearm, and the GPS unit is in constant communication with a mobile electronic device designed to detect the location of the firearm. The trigger is designed to lock when the GPS unit is not secured within the body of the firearm. A power source is additionally disposed within the firearm and designed to provide power to the GPS unit and a solar panel, operably connected to the power source, is located on the firearm. In this way, the firearm tracking system is designed to provide a constant and accurate location of a missing firearm.

Abstract: In one aspect, a magazine safety system for preventing loading of a live ammunition cartridge into a firing chamber of a firearm is provided. The firearm has an associated ammunition caliber. The safety system includes a safety block comprising an inner member configured for insertion along an inner surface of a wall of a magazine well of the firearm, the magazine well having an opening for receiving a magazine. An outer member is configured to attach to the inner member along an outer surface of the wall of the magazine well and one or more fasteners secure the inner member to the outer member to secure the wall of the magazine well between the inner member and the outer member.

Abstract: A firing device includes a magazine configured to receive a plurality of toy bullets and a turret connected with the magazine. A bottom plate of the magazine is provided with a bullet output port. The turret includes a conduit, a barrel aligned with the conduit, and a propelling device disposed between the conduit and the barrel. The conduit is disposed below the magazine and is provided with a guide slot including a bullet inlet substantially aligned with the bullet output port of the magazine.

Abstract: Rifle magazines with storage containers have a first elongated tubular body defining an ammunition passage, the first elongated tubular body having an upper end defining an ammunition feed aperture, the first elongated tubular body having a lower end having a first floor plate attachment facility, a magazine spring and follower contained in the ammunition passage, a floor plate having a first attachment feature adapted to connect to the first floor plate attachment facility, a second elongated tubular body defining a storage passage, the second elongated tubular body having an upper end having a second floor plate attachment facility, and the floor plate having a second attachment feature adapted to connect to the second floor plate attachment facility.

Abstract: A novel wearable apparatus for stabilizing a firearm is described. The “Third Arm” apparatus attaches to a tactical vest on one end, and the rail interface system of the firearm on the other end. The arm allows the user to move the firearm with minimum restrictions while providing complete counterbalancing of the firearm, removing the weight of the firearm from the user's arms, thus reducing arm fatigue and improving accuracy. The apparatus enables the use of unconventional weapons systems including high recoil firearms and skeletonized firearms. Third Arm provides a structure to distribute recoil forces and onto which recoil management systems can be placed to aid in shot consistency and reduce discomfort of recoil forces. The apparatus is adjustable for different sized users and different weight firearms.

Abstract: The invention relates to a long-range optical device, in particular a telescopic sight 1, with at least one objective lens 2 and at least one eyepiece 3 and with an adjustable reticle 6 arranged between the objective lens 2 and the eyepiece, wherein the reticle 6 is coupled to a manually operable fast reticle adjustment, wherein a display device 14 is arranged in the field of view of the long-range optical device 1, through which a distance value set by a setting device 4, 15 of the fast reticle adjustment can be read when using the long-range optical device 1.

Abstract: A weapon training system including a magnetic sensor system is described. The magnetic sensor system is insertable into or integrated with a round of an indirect firing weapon and includes at least one magnetic sensor and a microcontroller communicatively coupled to the at least one magnetic sensor. The microcontroller is configured to perform operations including receiving at least one proximity signal from the at least one magnetic sensor indicating a proximity of at least one magnet of at least one charge to the at least one magnetic sensor, determining, based on the at least one proximity signal, that the at least one charge is removably attached to the round, generating an output signal indicating that the at least one charge is removably attached to the round, and wirelessly transmitting the output signal to an electronic device.

Abstract: A weapon training system for an indirect firing weapon. The weapon training system includes a firing box including at least one processor, and a firing mechanism communicatively coupled with the firing box. Activation of the firing mechanism causes a simulated firing of the indirect firing weapon. The weapon training system also includes a round sensor communicatively coupled with the firing box. The round sensor is operable to be attached to or integrated with a round compatible with the weapon. The round is operable to be inserted into a breech of the weapon. The weapon training system further includes a breech sensor communicatively coupled with the firing box. The breech sensor is configured to detect an insertion of the round into the breech of the weapon via detection of the round sensor.

Abstract: An optical aiming scope mount (10) includes a base (12) configured to attach to a weapon system. At least two longitudinally spaced apart scope mounting rings (14, 16) are on the base. A first chamber (34) is formed in a portion of the base (12). A plurality of electrical connectors (38) on the base (12) are operatively joined by a circuit (46) at least partially located in the first chamber (34) to provide a power/data distribution bus.

Abstract: A snap-on clamp adapted to be removably connected to a part, the clamp including a U-shaped housing encompassing a space, the housing including a peak at a first end, a pair of side walls, each side wall extending from the peak and terminating at an edge, the pair of side walls cooperatively form two edges which define a mouth disposed at a second end opposingly disposed from the first end, the pair of side walls configured to be resiliently securable to the part. The two edges includes engaging surfaces urged towards one another and are configured to be removably coupled to the part when the clamp is urged with the mouth towards the part; and further including at least one protrusion disposed on at least one of the engaging surfaces, the at least one protrusion is configured to be lodged in a slot of the part.

Abstract: A firearm accessory mount for a take-down rifle is disclosed. The mount has a first portion having an accessory interface, and a second portion opposing the first portion. The second portion has a locking block with a proximal end and a distal end. The proximal end is shaped and positioned to engage a receiver assembly of the take-down rifle. At least one of the first portion or the second portion has a barrel engagement surface. A related method is also disclosed.

Abstract: A shirt system for supporting body armor may include an inner shirt and an outer shirt. The inner shirt may include a first pocket, the first pocket adapted to receive a first ballistic panel. The outer shirt may include a second pocket, the second pocket adapted to receive a second ballistic panel. The shirt system may include at least one connector adapted to extend from the first pocket to the second pocket. The first pocket may be located on a front side of the inner shirt and the second pocket may be located on a rear side of the outer shirt. The shirt system may include a side ballistic panel.

Abstract: The armouring system for a self-propelled work machine (1) comprises: a cab frame (10) for the machine (1); and a plurality of armouring elements (21, 22, 23, 24, 25), made of armoured material, adapted to be fixed removably to respective portions of the frame (10), in order to define an armoured cab (2).

Abstract: The following invention relates to split hulls, particularly to V shaped split hulls with a biased resilient member to mitigate against shock or blast. There is provided an armoured land vehicle comprising; a lower armoured v shaped hull; an upper hull which is located above and slidably engaged in a vertical plane with said hull, wherein there is at least one biased resilient member located between said upper hull and lower hull, to reduce the travel between said upper and lower hulls in the event of a shock event.

Abstract: A quick change target system including a frame, a target mounted to the frame, and a retainer movable between a first position retaining the target within the frame and a second position permitting removal of the target from the frame. The target is formed from a plurality of individual members that have markings, which collectively define aiming points on the target.

Abstract: The present invention relates to a cluster bomblet having an improved bomblet body, the cluster bomblet comprising: a cylindrical bomblet body (10) packed with high explosives; a fuse assembly (20) having a striker screw (21) for exploding the high explosives and coupled to the top side of the bomblet body; and a conical penetrator (15) provided inside the rear end portion of the bomblet body.

Abstract: The present invention relates to a combined fireworks with launching pits and multi-channel fireproof structures comprising a body, several tubular cavities are uniformly arranged on the body with the upper ports thereof are open and the lower ports thereof are closed, inner cylinders of fireworks and propellants are arranged inside the tubular cavity, the bottom of each tubular cavity is provided with annular grooves and launching pits. The bottom surface of the body is provided with several fireproof bosses, the position of each fireproof boss corresponds to each tubular cavity in the body respectively, and recessed countersinks are arranged on the fireproof bosses, the priming holes are arranged within the recessed countersinks, one end opening of the priming hole is located on the bottom surface of the launching pit, and the other end opening of the priming hole is located in the recessed countersinks.

Abstract: A cartridge comprising an elongate rifle bullet with a plurality of circumferential grooves having overmolded polymer therein defining embedded polymer rings. The cartridge further having a case and propellant. The polymer rings have an outer surface that is flush with, that is, conforming to the outer surface of the body. The polymer may have be selected to have a favorable coefficient of friction with respect to the barrel. The bands offering reduction of the metal to metal contact between the bullet and the barrel while not diminishing the ballistic coefficient of the bullet.

Abstract: A multiple shotgun shell clip including a base having mounting structures integrally incorporated therein and two parallel spaced apart sidewalls integrally formed with the base. The sidewalls are spaced apart a distance slightly less than the length of two shells. The upper edges of the sidewalls terminating in five arcuate indentations with indentations in one sidewall being disposed coaxially with indentations in the other sidewall. Each of the indentations including an arc equal to or slightly greater the diameter of a shell. A first of two adjacent indentations in the two sidewalls defining a first set of four shell retainers and a second two adjacent indentations defining a second set of four shell retainers. A fifth middle indentation defines a shell-sized space between the first and second set of four shell retainers and either of the middle fifth indentations defining a retainer for a make-ready shell.

Abstract: An indicator inspection machine inspects the accuracy of an indicator based on a value displayed by the indicator when a spindle changes position. The indicator inspection machine includes a measurement spindle provided so as to be freely raised and lowered in order to displace the spindle of the indicator; a contact point provided to a distalmost end of the measurement spindle, the contact point making contact with an indicator contact point provided to a distalmost end of the spindle of the indicator; a drive mechanism driving the measurement spindle; and a controller controlling the drive mechanism so as to bring the contact point into contact with the indicator contact point while changing a speed of the measurement spindle at a predetermined periodicity.

Abstract: An measurement apparatus for measuring end play of a linear actuator features a dial indicator and a primary mounting clamp. A plunger of the dial indicator is displaceable back and forth to cause an indicator needle to move about a graduated dial to reflect a measurement of said displacement. The primary mounting clamp has a clamp body configured to releasably clamp onto an output rod of said linear actuator, and a dial support body projecting outwardly from said clamp body. The dial support body is configured to the support the dial indicator thereon in a working position in which the plunger reaches axially along the output rod toward a gear housing of said linear actuator to abut against a contact surface carried on a stationary portion of the actuator relative to which the output rod undergoes displacement during operation of said actuator.

Abstract: A shape measuring device configured to measure a shape of a surface to be measured of a target object, the device includes: a holder configured to hold the target object; a sensor configured to measure a shape of the surface to be measured and output a measurement value; a sensor rotating mechanism configured to rotate the sensor about a first axis; a sensor moving mechanism configured to move the sensor on a second axis; a holder moving mechanism configured to move the holder along a third axis; and a processor configured to: calculate a shape of the surface to be measured based on the measurement value; calculate a position of a center of sphere of the surface to be measured; and control the holder moving mechanism to match the position of the center of sphere with the intersection of the first axis and the second axis.

Abstract: Methods and systems for measuring a distance include measuring a first interference pattern between a lens and a target surface using a light source at a first wavelength. A second interference pattern is measured between the lens and the target surface using a light source at a second wavelength, different from the first wavelength. An absolute measurement of a distance between the lens and the target surface is determined based on the first interference pattern and the second interference pattern.

Abstract: Systems for measuring a distance include a lens positioned a distance above a target surface. A camera is configured to measure a first interference pattern between the lens and the target surface using a light source at a first wavelength and to measure a second interference pattern between the lens and the target surface using a light source at a second wavelength. A processor is configured to determine an absolute measurement of the distance between the lens and the target surface based on the first interference pattern and the second interference pattern.

Abstract: A beam-shaping optical system suitable for use with optical coherence tomography having a beam-shaping insert having a polymeric material, the beam-shaping insert integrally defining a beam-shaping element. The beam-shaping element has a reflective element positioned on a curved surface. A light source generates an electromagnetic beam. An optical fiber having a core and a cladding, the optical fiber having first end optically coupled with the light source and a fiber end. The fiber end is configured to emit the electromagnetic beam toward the beam-shaping element. The reflective element has a reflectivity greater than about 98% for both a first wavelength band of the electromagnetic beam and a second wavelength band of the electromagnetic beam.

Abstract: Various balanced detection systems which reduce alignment requirements of free space optics based balanced detection configurations are discussed. One example system includes a light source, a beam divider, sample optics, return optics, and a processor. The light source generates a light beam. The beam divider separates the light beam into reference and sample arms. The sample optics deliver the light beam in the sample arm to a light scattering object to be imaged. The return optics direct light to a balanced detection system, which has a balanced detection beam divider for combining light scattered from the object and light from the reference arm and directing the combined light into two detection channels and two detectors for collecting the combined light in the two detection channels and generating signals in response thereto. The processor processes the signals and generates image data of the object based on the processed signals.

Abstract: A scanning probe responsive in three axes is provided for use in a coordinate measuring machine. The scanning probe includes a frame, a stylus suspension portion and a stylus position detection portion. The stylus position detection portion includes a light source that is operated to radiate source light toward a position indicating element that is fixed relative to the stylus coupling portion. The position indicating element includes a position indicating emitter having an emitter material (e.g., phosphor) that inputs and absorbs the light from the light source and responds by outputting excitation light. In various implementations, the excitation light is directed as at least one of axial measurement light along an axial measurement spot path to form an axial measurement spot on an axial position sensitive detector and/or rotary measurement light along a rotary measurement spot path to form a rotary measurement spot on a rotary position sensitive detector.

Abstract: Examples of the present disclosure describe systems and methods for capturing data to acquire indoor and outdoor geometry. In aspects, a data capture system may be configured to acquire texture data, geometry data, navigation data and/or orientation data to support geolocation and georeferencing within indoor and outdoor environments. The data capture system may further be configured to acquire seamless texture data from a 360° horizontal and vertical perspective to support panoramic video and images.

Abstract: A device for measuring heights and/or thicknesses on a measurement object, includes (i) a first low-coherence interferometer for combining, in one spectrometer, a reference optical beam and a measurement optical beam originating from reflections of the light on interfaces of the measurement object, to produce a grooved spectrum signal with spectral modulation frequencies, (ii) apparatus for measuring an item of position information representative of the relative optical length, (iii) electronic and calculating apparatus arranged for determining at least one spectral modulation frequency representative of an optical path difference between the measurement optical beam and the reference optical beam, and for determining, by exploiting the item of information and the spectral modulation frequency, at least one height and/or thickness on the measurement object, and (iv) second optical apparatus for measuring distance and/or thickness with a second measurement beam incident on the measurement object on a second fa

Abstract: Disclosed are an apparatus for measuring a displacement using a fiber Bragg grating sensor, which is applied to a strain sensor using the fiber Bragg grating sensor, and a method of controlling sensitivity and durability of the same. The apparatus includes: a case forming an external appearance; third and fourth optical fibers having mutually different numbers of strands and installed in the case while being spaced apart from each other by a predetermined interval; and a connection unit installed between the third and fourth optical fibers and fixed at a predetermined position by tension applied to the third and fourth optical fibers, wherein the fiber Bragg grating sensor is installed to one selected from the pair of optical fibers having mutually different numbers of strands, so that measurement sensitivity and durability are controllable.

Abstract: The invention relates to an apparatus (110) and a method (152) for determining a deformation (170) of a three-dimensional, flexible structure in form of a tubular construct (112). Here, at least one optical waveguide (116) is introduced into the tubular construct (112), wherein the optical waveguide (116) extends in form of a helical winding (118) within the tubular construct (116) and has a multiplicity of strain measuring means (126). The apparatus (110) further comprises at least one evaluation device (130) which is configured to determine the deformation of the tubular construct (112), in particular in relation to an axis, surface and/or volume of the construct (112), from measurement values (154) from the multiplicity of strain measuring means (126).

Abstract: A system and device that measures a specimen's surface profile by passing a bright white light source through a series of lenses which generate repeatable chromatic focal shift variations of wavelengths of white light for Z axis measurements. The movement of the sensor along an X-Y raster pattern is controlled by a X-directional and Y-directional scanner used in combination with X and Y actuators. The system and device translate the chromatic focal shifts into digital data which may then be used to both control the position of the lenses along the surface of the specimen and generate a 3D topographical images of the specimens being profiled.

Abstract: The present disclosure relates to an image processing apparatus and method, data, and a recording medium by which the invisibility of corresponding point detection can be improved. A pattern picked up image obtained by image pickup, by an image pickup section, of a predetermined structured light pattern projected by a projection section and having a plurality of, for example, patterns 101-1 and 102-2 and so forth, each of which has a luminance distribution of a Gaussian function like, for example, a curve 102-1 or 102-2, disposed therein, is used to detect corresponding points between a projection image projected by the projection section and a picked up image picked up by the image pickup section. The present disclosure can be applied, for example, to an image processing apparatus, a projection apparatus, an image pickup apparatus, a projection image pickup apparatus, a control apparatus, a projection image pickup system and so forth.

Abstract: A three-dimensional (3D) measurement system, method and computer program product are provided. The system includes a noncontact measurement device that measures a distance from the noncontact measurement device to a surface. The device includes a projector that emits a light pattern. A measurement camera is coupled to the noncontact measurement device. A first color camera is provided having a first quality parameter. A second color camera is coupled to the device, the second color camera having a second quality parameter, the second quality parameter being larger than the first quality parameter. One or more processors are operably coupled to the noncontact measurement device that determine 3D coordinates of at least one point in a field of view and selectively acquiring an image with the second color camera.

Abstract: In order to quickly determine three-dimensional contours, for example, in real time for industrial processes, capturing and processing data has to be optimized. This is performed by the method according to the invention which includes a step of initially determining a coarse position of the light line image by a position scan with reduced resolution and therefrom automatically defining windows on the sensor which include an entire line image so that the data only has to be read from the windows during the subsequent measuring scan which is performed with a higher resolution compared to the position scans.

Abstract: The present invention relates to a parallelism control system of an emission laser light optical axis and a target tracking optical axis, including an optical axis parallelism detection unit, a control unit, a target tracking optical axis correction unit and an emission laser light optical axis correction unit; wherein the optical axis parallelism detection unit is configured to detect the offset amount of the target tracking optical axis and the offset amount of the emission laser light optical axis; the control unit is configured to control the target tracking optical axis correction unit according to the offset amount of the target tracking optical axis, and control the emission laser light optical axis correction unit according to the offset amount of the emission laser light optical axis.

Abstract: A method of determining an edge roughness parameter has the steps: (1010) controlling a radiation system to provide a spot of radiation at a measurement position for receiving a substrate; (1020) receiving a measurement signal from a sensor for measuring intensity of a forbidden diffraction order (such as a second order) being diffracted by a metrology target at the measurement position when the metrology target is illuminated by the spot of radiation, the metrology target comprising a repetitive pattern being configured by configuration of a linewidth/pitch ratio (of about 0.5) to control an amount of destructive interference that leads to forbidding of the diffraction order, the sensor being configured to provide the measurement signal based on the measured intensity; and (1040) determining an edge roughness parameter based on the measured intensity of the forbidden diffraction order.

Abstract: A method of non-destructively evaluating a thickness of a coating layer including a coating material on a turbine engine component includes placing first and second probes on an outer surface of the coating layer. The first and second probes are separated by a first distance. The first and second probes are configured to generate an electrical current in the coating layer. The method further includes placing third and fourth probes on the outer surface of the coating layer in a location that is between the first and second probes. The third and fourth probes are separated by a second distance that is less than the first distance. Still further, the method includes generating an electrical current in the coating layer using the first and second probes, measuring the electrical voltage using the third and fourth probes, and calculating the thickness of the coating layer based on the measured electrical voltage.

Abstract: An adhesively coupled power-meter measures one or more of force, torque, power, and velocity of a mechanical arm. The power meter includes a plate with a first surface prepared for adhesively coupling to the mechanical arm. At least one strain gauge is physically coupled with a second surface, opposite the first, of the plate and with an orientation corresponding to an orientation of the adhesively coupled power meter such that mechanical forces are transferred from mechanical arm to the at least one strain gauge when the plate is adhesively coupled to the mechanical arm. The power meter also includes electronics for receiving a signal from the at least one strain gauge and for determining one or more of force, torque, power and velocity from the signal, and a wireless transmitter for transmitting one or more of force, torque, power and velocity to a receiving device.

Abstract: A microcontroller controlled altimeter includes a microcontroller, a digital altitude pressure sensor with a pressure indicating output coupled to the microprocessor, and at least one Form A solid state relay coupled to the microcontroller, where the microcontroller is configured to provide control signals to the at least one Form A solid state relay to provide an open circuit between normally open and common terminals of the at least one Form A solid state relay if the digital altitude pressure sensor output is less than, or equal to, a setpoint for the at least one Form A relay, and provide continuity between the normally open and common terminals of the at least one Form A solid state relay if the digital altitude pressure sensor output is greater than the setpoint for the at least one Form A relay.

Abstract: An electronic device is provided. The electronic device includes a barometer sensor configured to measure a barometric pressure of the electronic device, a motion sensor configured to detect a motion of the electronic device, and a processor configured to obtain, using the barometer sensor, first data relating to a change of the barometric pressure, obtain, using the motion sensor while the first data is obtained, second data relating to the motion of the electronic device, and if the first data corresponds to the second data, determine the first data as data corresponding to the barometric pressure.

Abstract: A leveling tool useful for determining levelness with multiple inclinations is disclosed herein. The leveling tool includes a level frame having four flat exterior faces able to be placed against a workpiece, four transparent reservoirs containing fluid and air, and magnets integrated within the level frame. The reservoirs are oriented at angles of zero, thirty, forty-five, and ninety degrees relative to one of the exterior faces, respectively. This variety of exterior faces and angled reservoirs allows the reservoirs to be used to indicate level of a workpiece if the workpiece is oriented at any summation of zero, thirty, forty-five, and ninety degrees of level. The magnets within the level frame allows the level frame to be removably coupled to a ferrous workpiece.

Abstract: A sea-floor tethered float instrument containing an accelerometer for measuring wave induced water velocity, ocean currents, relative swell kinetics and the like.

Abstract: Method for operation of a strap-down ship's gyro compass for optimal calculation of position and course angle on a ship, with three rotational rate sensors each mutually aligned to each other at a right angle, and two nominally horizontally aligned orthogonal acceleration sensors, without required specification of the geographic latitude and/or of the speed of the ship, characterized by the steps: a. Preparation of a set of dynamic equations based on the angular velocity components detected by the rotational rate sensor, b. Preparation of a measured data equation based on the force components detected by the acceleration sensors, c. Determination of the properties of the lever arm between the strap-down ship's gyro compass and the point of rotation of the ship, and d.

Abstract: A waveguide optical gyroscope (WOG) is disclosed. One WOG may comprise an amplified spontaneous emission (ASE) source, a sensor comprising a waveguide loop disposed in a first cladding material interposed between layers of at least a second cladding material having an index of refraction lower than an index of refraction of the first cladding material, wherein the sensor is configured to receive an output signal of the ASE source, and a pump source configured to pump the first cladding material with an in-plane pump signal.

Abstract: A method and system for a robotic device comprising a propulsion mechanism, a sensor for sensing objects, a localization and mapping system, a processing facility comprising a processor and a memory, the processing facility configured to store a set of instructions that, when executed, cause the robotic device to upon selection by a user, place the robotic device in a mapping mode, wherein the mapping mode causes the robotic device to move through the service area and create a digital map, and upon selection by the user, place the robotic device in a service task mode, wherein while in service task mode the robotic device performs a service task in the service area based on sensing the service area with the sensor and utilizing the created digital map.

Abstract: A method and an apparatus for determining a vehicle position in a fixed-traffic-node coordinate system. The apparatus includes at least one receiver for receiving a signal from a traffic-node transmission device, at least one device for determining an item of direction-of-travel information in a global reference coordinate system and at least one evaluation device. A spatial relationship between the global reference coordinate system and the fixed-traffic-node coordinate system is known in advance. The evaluation device can be used to take at least one signal property of a received signal as a basis for determining a position of the traffic-node transmission device in a vehicle coordinate system. The evaluation device can be used to determine the vehicle position in the fixed-traffic-node coordinate system on the basis of the direction-of-travel information and the position of the traffic-node transmission device in the vehicle coordinate system.

Abstract: An estimation device includes a detecting unit that detects acceleration; an acquiring unit that acquires a feature value that is based on the acceleration; and an estimation unit that estimates a speed based on a limit value of the feature value.

Abstract: Methods, architectures, apparatuses, systems, devices, and computer program products directed to device position tracking are provided. Device position tracking may rely on maintaining frame alignment between tracking-system and tracked-device frames. Performing frame alignment may include determining an alignment transformation that may (e.g., best) align a linear position measured at a tracking system with a linear acceleration measured at a tracked device. The alignment transformation may be applied to align the linear position and any signal in the device frame, such as any of angular velocity, angular acceleration, angular position, gravity, linear velocity, linear position or magnetometer in the device frame. Once aligned, the linear position and such signal in the device frame may be combined.