Optical instruments

Claim 2

A scanning radiometer comprising, in combination: input optics having an optical axis and arranged to create, in an image plane generally transverse to said axis, a primary image of the radiation from a field of view; a scanner assembly rotatable about said axis for converting the scan of an arcuately related succession of field elements in said plane into rotation of a beam directed generally along said axis accompanied by apparent transverse movement of the field across the beam, the instantaneous intensity of said beam being that of the image field element at each particular rotated position of said assembly; radiation responsive means; and relay optics for focusing said beam from said assembly on said radiation response means.

Claim 3

Apparatus according to claim 1 in which said input optics includes a spherical element and said relay optics includes means for correcting said beam for spherical aberration introduced by said spherical element.

Claim 4

Apparatus according to claim 1 in which said input optics includes a spherical mirror and said relay optics includes catoptric means for correcting said beam for aberrations introduced by said spherical mirror.

Claim 5

Optical apparatus comprising, in combination: a double folding scanner assembly arranged for rotation about an axis and including a first mirror through which said axis extends at an acute angle and a second mirror spaced from and rotatable unitarily with said first mirror so that upon rotation of said assembly said second mirror traces a surface which is a frustum of a right circular cone coaxial with the axis of rotation, said mirrors being normal to a common plane containing said axis; input optics having an axis coincident with that of said scanner assembly and arranged to create a primary image of an off-axis instantaneous field in an image plane intersecting said frustum, the angular relation between said mirrors being such that radiation from said primary image is reflected by said mirrors sequentially in a beam directed along said axis regardless of the rotated position of said assembly, the area of said second mirror projected on said image plane being comparable to the size of said field of view at said image plane; and means mounted to receive said beam for giving an output determined thereby, so that as said scanner assembly rotates said output is representative of the intensity of the radiation from arcuately related series of portions of said image plane.

Claim 6

Optical apparatus comprising, in combination: a double folding scanner assembly arranged for rotation about an axis and including a first mirror through which said axis extends at an acute angle and a second mirror spaced from and rotatable unitarily with said first mirror so that upon rotation of said assembly said second mirror traces a surface which is a frustum of a right circular cone coaxial with the axis of rotation, said mirrors being normal to a common plane containing said axis; input optics having an axis coincident with that of said scanner assembly and arranged to create a primary image of an off-axis instantaneous field in an image plane intersecting said frustum, the angular relation between said mirrors being such that radiation from said primary image is reflected by said mirrors sequentially in a beam directed along said axis regardless of the rotated position of said assembly, the area of said second mirror projected on said image plane being comparable to the size of said field of view at said image plane; and means mounted to receive said beam for giving an output determined thereby, so that as said scanner assembly rotates said output is representative of the intensity of the radiation from arcuately related series of portions of said image plane.

Claim 7

Apparatus according to claim 4 in which said input optics includes a spherical element; and relay optics mounted on said axis for receiving said beam and correcting it for spherical aberration introduced by said spherical element.

Claim 8

Apparatus according to claim 4 in which said input optics includes a spherical mirror and relay optics mounted on said axis for receiving said beam, and including catoptric means for correcting for spherical aberration introduced by said spherical mirror.

Claim 9

A wide field catoptric optical system having an entrance pupil and comprising, in combination: a primary spherical mirror having a central aperture; a plane secondary mirror; an initial plane scanning mirror rotatable about an axis external thereto which makes an acute angle with the plane thereof; another plane scanning mirror rotatable about said axis, which passes therethrough and makes an acute angle with the plane thereof; means causing simultaneous rotational motion of said scanning mirrors; a first relay mirror mounted on said axis and having a central aperture; a second relay mirror mounted on said axis and having a central aperture; and radiation responsive means mounted on said axis; said mirrors being positioned so that radiation passing said entrance pupil in a direction having a major component parallel to said axis is reflected from said primary spherical mirror and said plane secondary mirror to focus at a primary image plane which said initial scanning mirror continuously intersects at an acute angle, so that radiation from said image plane is serially reflected by said scanning mirrors as a beam emerging coaxial with said axis, and so that said beam passes through all said central apertures and is focused by said relay mirrors on said detector means, the central aperture of one of said relay mirrors comprising the aperture stop of the system.

Claim 10

A wide field catoptric optical system having an entrance pupil and comprising, in combination: a primary spherical mirror having a central aperture; a plane secondary mirror; an initial plane scanning mirror rotatable about an axis external thereto which makes an acute angle with the plane thereof; another plane scanning mirror rotatable about said axis, which passes therethrough and makes an acute angle with the plane thereof; means causing simultaneous rotational motion of said scanning mirrors; a first relay mirror mounted on said axis and having a central aperture; a second relay mirror mounted on said axis and having a central aperture; and radiation responsive means mounted on said axis; said mirrors being positioned so that radiation passing said entrance pupil in a direction having a major component parallel to said axis is reflected from said primary spherical mirror and said plane secondary mirror to focus at a primary image plane which said initial scanning mirror continuously intersects at an acute angle, so that radiation from said image plane is serially reflected by said scanning mirrors as a beam emerging coaxial with said axis, and so that said beam passes through all said central apertures and is focused by said relay mirrors on said detector means, the central aperture of one of said relay mirrors comprising the aperture stop of the system.

Claim 11

Apparatus according to claim 7 in which one of said relay mirrors is figured to correct the spherical aberration introduced by all said spherical mirrors.

Claim 12

Apparatus according to claim 7 in which said relay mirrors are between said scanning mirrors and said primary spherical mirrors.

Claim 13

Apparatus according to claim 7 in which said primary spherical mirror is between said scanning mirrors and said relay mirrors.

Claim 14

Apparatus according to claim 8 in which said beam falls on said figured relay mirror for reflection to the other relay mirror.

Claim 15

Apparatus according to claim 7 in which the dihedral angles of said scanning mirrors are such that radiation entering said pupil at an angle of 5 1/2 * with respect to said axis emerges from said second scanning mirror as a beam aligned with said axis, for all rotated positions of said scanning mirrors.

Claim 16

Apparatus according to claim 7 in which the center of curvature of said primary spherical mirror is in the plane of said entrance pupil.