A technique for preventing decrease in accuracy of measuring a tilt angle of a surveying device is provided. A total station includes a rotating unit, a horizontal angle measuring unit, a tilt sensor, and a tilt amount calculating part. The rotating unit has a distance measuring unit that performs optical surveying, and the rotating unit horizontally rotates. The horizontal angle measuring unit measures a rotation angle of the horizontal rotation of the rotating unit. The tilt sensor measures a tilt of the rotating unit relative to the direction of gravity. The tilt amount calculating part calculates a tilt of the rotating unit on the basis of measured values of the horizontal angle measuring unit before and after the rotating unit rotates.

A method for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates. An annular coplanar capacitance measuring head of a sensor unit consists of four quarter round metal plates and four quarter circular-ring-shaped metal plates, the eight metal plates are coplanar and concentric with one another, and a quarter round metal plate and a quarter circular-ring-shaped metal plate corresponding to the same sector angle form a capacitor. Two annular coplanar capacitance measuring heads are arranged on two round insulating substrates, the two round insulating substrates are used as two bottom surfaces of a cylindrical container, the cylindrical container is transversely arranged, and an insulating liquid equal to volume of the cylindrical container is injected into the cylindrical container in a sealing manner. Potential leads extract potentials of the sixteen metal plates and are connected to an input end of a capacitance measuring unit, and the capacitance measuring unit is connected to a dip measuring unit. When the cylindrical container tilts, the relative positions of the two annular coplanar capacitance measuring heads and the insulating liquid are changed, and a dip angle value can be calculated by measuring the change of a capacitance value. Also disclosed is a device for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates.

A method for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates. An annular coplanar capacitance measuring head of a sensor unit consists of four quarter round metal plates and four quarter circular-ring-shaped metal plates, the eight metal plates are coplanar and concentric with one another, and a quarter round metal plate and a quarter circular-ring-shaped metal plate corresponding to the same sector angle form a capacitor. Two annular coplanar capacitance measuring heads are arranged on two round insulating substrates, the two round insulating substrates are used as two bottom surfaces of a cylindrical container, the cylindrical container is transversely arranged, and an insulating liquid equal to volume of the cylindrical container is injected into the cylindrical container in a sealing manner. Potential leads extract potentials of the sixteen metal plates and are connected to an input end of a capacitance measuring unit, and the capacitance measuring unit is connected to a dip measuring unit. When the cylindrical container tilts, the relative positions of the two annular coplanar capacitance measuring heads and the insulating liquid are changed, and a dip angle value can be calculated by measuring the change of a capacitance value. Also disclosed is a device for measuring a dip angle of oppositely crossly placed paired quartered ring-quartered circle nested polar plates.

The present invention provides a measuring device, which comprises a leveling unit, a measuring device main body provided on the leveling unit, a control unit, a first tilt angle measuring device for detecting a horizontality with high accuracy, and a second tilt angle measuring device for detecting a tilt angle in a wider range than a range of the first tilt angle measuring device and having a higher responsiveness than a responsiveness of the first tilt angle measuring device, wherein the control unit, the first tilt angle measuring device and the second tilt angle measuring device are provided in the measuring device main body and wherein the control unit drives the leveling unit based on a detection result of the second tilt angle measuring device, performs a rough leveling until a tilt angle detected by the second tilt angle measuring device reaches within a range in which the first tilt angle measuring device is capable of detecting and levels the measuring device main body horizontally based on a detection result of the first tilt angle measuring device.

The present invention provides a measuring device, which comprises a leveling unit, a measuring device main body provided on the leveling unit, a control unit, a first tilt angle measuring device for detecting a horizontality with high accuracy, and a second tilt angle measuring device for detecting a tilt angle in a wider range than a range of the first tilt angle measuring device and having a higher responsiveness than a responsiveness of the first tilt angle measuring device, wherein the control unit, the first tilt angle measuring device and the second tilt angle measuring device are provided in the measuring device main body and wherein the control unit drives the leveling unit based on a detection result of the second tilt angle measuring device, performs a rough leveling until a tilt angle detected by the second tilt angle measuring device reaches within a range in which the first tilt angle measuring device is capable of detecting and levels the measuring device main body horizontally based on a detection result of the first tilt angle measuring device.

A non-electronic head-worn system for providing visual inertial head orientation information to a person is disclosed. The system comprises a head-worn unit that displays at least one orientation reference symbol to the person wearing the unit wherein the orientation reference symbol stays in a fixed visual position for the person when the person's head changes orientation. The system comprises an optical element located in the optical path between the user's eye and the orientation reference symbol, such as a lens, mirror, a prism, a beam splitter, a retro-reflector, or any other device or medium that can change the appearance or apparent location of an image. The system further comprises a pitch indicator that gives visual pitch information to the person and/or a roll indicator that gives visual roll information to the person. The pitch indicator and the roll indicator are responsive to a pendulum, a rolling element, or a fluid in a reservoir. The pitch element and the roll element do not use electricity or electronics.

A non-electronic head-worn system for providing visual inertial head orientation information to a person is disclosed. The system comprises a head-worn unit that displays at least one orientation reference symbol to the person wearing the unit wherein the orientation reference symbol stays in a fixed visual position for the person when the person's head changes orientation. The system comprises an optical element located in the optical path between the user's eye and the orientation reference symbol, such as a lens, mirror, a prism, a beam splitter, a retro-reflector, or any other device or medium that can change the appearance or apparent location of an image. The system further comprises a pitch indicator that gives visual pitch information to the person and/or a roll indicator that gives visual roll information to the person. The pitch indicator and the roll indicator are responsive to a pendulum, a rolling element, or a fluid in a reservoir. The pitch element and the roll element do not use electricity or electronics.

A tilt detecting device comprising, a light source for projecting a pattern, a liquid component having a free liquid surface and for rear-surface reflecting by the free liquid surface, a photodetection element for photodetecting a reflection image of the rear-surface reflected pattern, and an arithmetic processing unit, wherein the arithmetic processing unit is adapted to scan a predetermined range of a photodetection surface of the photodetection element as many times as required and performs averaging processing to a photodetection signal as detected and calculates a barycentric position of the pattern based on signals subjected to averaging processing.

A tilt detecting device comprising, a light source for projecting a pattern, a liquid component having a free liquid surface and for rear-surface reflecting by the free liquid surface, a photodetection element for photodetecting a reflection image of the rear-surface reflected pattern, and an arithmetic processing unit, wherein the arithmetic processing unit is adapted to scan a predetermined range of a photodetection surface of the photodetection element as many times as required and performs averaging processing to a photodetection signal as detected and calculates a barycentric position of the pattern based on signals subjected to averaging processing.

Disclosed is a visual tool for determining the spatial orientation of an aircraft relative to a level plane, including a closed container constructed of a material that permits the passage of light therethrough. An indicator body is fixed within the container and viewable through the container. An indicator fluid is provided including a liquid that fills the container a selected amount. The indicator fluid presents a fluid surface that is viewable through the container and free to move within the container. When the visual tool is affixed to an aircraft the indicator body and the fluid surface are parallel to the level plane when the aircraft is level. The indicator body is moved out of the level plane and the fluid surface remains parallel to the level plane when the aircraft deviates from the level plane to generate a visual signal representative of the orientation of the aircraft.