Telescope system

A telescope system comprising:

• a telescope comprising a position-sensitive detector that is offset from a focal plane of the telescope;
• and
• a selective shielding unit configured to shield the position-sensitive detector, the selective shielding unit comprising:
• a first member comprising a periodic arrangement of slits;
• and
• a second member comprising the periodic arrangement of slits, wherein the second member is arranged parallel to the first member and the periodic arrangement of slits of the second member are rotationally offset with respect to the periodic arrangement of slits of the first member.

A telescope system comprising:

• a telescope;
• and
• a selective shielding unit including at least one member including a passage allowable region for an observation target electromagnetic wave and a passage blocking region for the observation target electromagnetic wave, wherein the telescope includes a position detectable detector that detects the observation target electromagnetic wave on a surface different from a focal plane of the telescope,
• the selective shielding unit is disposed on a front side of the position detectable detector, and
• patterns of the passage allowable region and the passage blocking region of the at least one member and disposition of the at least one member are set to allow for reconstruction of an observation image based on an image detected in the position detectable detector,
• wherein the reconstruction is performed by acquiring, in advance, a correspondence relation between an incident angle of an electromagnetic wave and a pattern of an image detected in the position detectable detector with respect to the electromagnetic wave at the incident angle and referring to the acquired correspondence relation.