A polar axis calibration system (100) comprises: a polar scope (10), a polar axis calibration control device (20) and a display device (30). The polar scope comprises an optical lens (11) and an image sensor (12) for collecting constellation images (IM); the polar axis calibration control device receives the constellation images from the polar scope and determines the position (P1) of the rotation center of the polar axis and the celestial pole position (P2), the position of the rotation center of the polar axis means the position of the rotation center (R0) of the polar axis (510) of the equatorial instrument in the plane of the constellation image, and the celestial pole position means the position of the celestial pole in the plane of the constellation image; and the display device is coupled to the polar axis calibration control device and used to display the constellation image, the celestial pole position and the position of the rotation center of the polar axis. The present invention also provides a polar scope, a polar axis calibration control device, as well as an equatorial instrument (500) and an astronomical telescope comprising the aforesaid polar scope or polar axis calibration system. According to the present disclosure, it is possible to align the celestial pole position directly with the rotation center of the polar axis, thus improving the calibration accuracy. Furthermore, it is possible to lower the requirements for the installation accuracy of the polar scope.

A polar axis calibration system (100) comprises: a polar scope (10), a polar axis calibration control device (20) and a display device (30). The polar scope comprises an optical lens (11) and an image sensor (12) for collecting constellation images (IM); the polar axis calibration control device receives the constellation images from the polar scope and determines the position (P1) of the rotation center of the polar axis and the celestial pole position (P2), the position of the rotation center of the polar axis means the position of the rotation center (R0) of the polar axis (510) of the equatorial instrument in the plane of the constellation image, and the celestial pole position means the position of the celestial pole in the plane of the constellation image; and the display device is coupled to the polar axis calibration control device and used to display the constellation image, the celestial pole position and the position of the rotation center of the polar axis. The present invention also provides a polar scope, a polar axis calibration control device, as well as an equatorial instrument (500) and an astronomical telescope comprising the aforesaid polar scope or polar axis calibration system. According to the present disclosure, it is possible to align the celestial pole position directly with the rotation center of the polar axis, thus improving the calibration accuracy. Furthermore, it is possible to lower the requirements for the installation accuracy of the polar scope.

An optical communication unit for sending and receiving optical communication signals is described. The optical communication unit includes an optical unit, an elevation drive and an azimuth drive. The optical unit emits and/or receives optical communication signals. The elevation drive is coupled with the optical unit by way of an elevation bearing and swivels the optical unit about an elevation axis. The azimuth drive is coupled with the optical unit and the elevation drive and turns the optical unit together with the elevation drive about an azimuth axis. The elevation axis is arranged eccentrically with respect to the azimuth axis, so that the elevation axis is offset with respect to the azimuth axis by a lateral offset. This allows the optical unit to be swiveled to alongside the azimuth drive, so that a swiveling range of the optical unit is increased.

The present invention relates to a method for readjusting a parallactic or azimuthal mounting, comprising a device which is intended for positioning and moving a telescope with a camera and can be aligned and readjusted by means of at least one image sensor and an electromotorized controller, characterized in that the image sensor acts as a main recording sensor of the camera and at the same time as an alignment sensor and readjustment control sensor, wherein before and after a main image is taken at least one control image is taken with a shorter exposure time and these control images are compared with one another, or at least a main image itself acts as a control image and is compared with at least one previous main image, or a short-exposed control image is compared with the main image itself and the correction values for the readjustment of the mounting are determined by the image offset and the time difference of the images taken. The method is the prerequisite for easy, error-free operation of an astronomical mounting for the purpose of long-exposure astronomical photography.

A tracking mount for an astronomical equipment includes castellations in a semicircular arrangement at a first end of a base member. The base member has a through hole formed at a radial center of the castellations. Additionally, the tracking mount includes a tracking arm having a shaft extending perpendicular to a long axis of the tracking arm and a set of teeth formed at a position distal to the shaft. The shaft has a notch formed at an end opposite the tracking arm. The shaft is dimensioned to be inserted into the through hole. A coil torsion spring having a crossbar formed at one end is mated with the notch on the shaft. A selector structure formed at another end of the torsion spring is dimensioned to sit within a castellation of the plurality of castellations. Adjusting the position of the selector structure relative to the plurality castellations adjusts the torsion coefficient of the coil torsion spring.

An on-gimbal telescope pointing assembly can include a head mirror operable to rotate to adjust an elevation angle of the pointing assembly and an all-reflective telescope operable to rotate to adjust an azimuth angle of the pointing assembly. The all-reflective telescope can include a fold mirror defining an output coude path of the all-reflective telescope. The pointing assembly can be operable to rotate about the coude path such that receiving optics can remain fixed while the pointing assembly rotates.

An apparatus continuously rotates an optical output about axis of rotation of the optical output. An input is centered on an optical axis of the apparatus and receives an optical input. An output is centered on the optical axis of the apparatus and provides an optical output. A group of five fixed fold mirrors is configured in a W orientation to receive the optical input and continuously rotates the optical output about the optical axis of the apparatus.

An improved astronomy counterweight featuring an adjustable weight and adjustable bore hole diameter is disclosed which includes an inner adapter, a main body weight, a bottom lid plate, a locking bolt, and attachment bolts which connect the components through bolt holes. The inner adapter can be swapped with one of a different bore hole diameter, allowing attachment to telescope mounts with varied shaft diameters. The invention can be configured to include or exclude components varying weight. In one embodiment, there are additional weight plates which may be utilized to adjust the weight of the counterweight.