CN102147519A - Wide-angle and long-rear working distance full-color objective lens of aerial survey camera - Google Patents

Abstract

A full-color objective lens of an aerial survey camera with wide angle and long back working distance adopts a reverse remote structure, namely a structure with separated negative and positive lenses; wherein the negative focal power lens group is used as a front group, and the positive focal power lens group is used as a rear group; the front group consists of a first lens, a second lens and a third lens in sequence; the rear group consists of a fourth lens, a fifth lens, a first doublet, a diaphragm, a third doublet, a second doublet and a convex flat lens in sequence; the elements of each group in the front group and the rear group are sequentially arranged along the optical axis. The invention simultaneously realizes large view field, long back working distance, high resolution and low distortion.

Description

Translated fromChinese

一种宽角和长后工作距离的航测相机全色物镜A Panchromatic Objective Lens for Aerial Survey Camera with Wide Angle and Long Back Working Distance

技术领域technical field

本发明涉及一种全色物镜，特别是一种宽角和长后工作距离航测相机全色物镜，主要应用于拼接式大面阵数字航测相机中。The invention relates to a panchromatic objective lens, in particular to a panchromatic objective lens for aerial survey cameras with wide angle and long rear working distance, which is mainly used in spliced large area array digital aerial survey cameras.

背景技术Background technique

目前的面阵数字航测相机主要有Z/I公司的DMC相机与奥地利V2xcel的UltraCam X(简称UCX，是UltraCam D的升级版本)数字航测相机。它们尚存在一些不足：像幅较小、分辨力较低；物镜视场较小、物镜型号单一；各全色相机曝光的差异引起图像拼接的差异。The current area array digital aerial survey cameras mainly include the DMC camera of Z/I Company and the UltraCam X (UCX for short, an upgraded version of UltraCam D) digital aerial survey camera of Austria V2xcel. They still have some shortcomings: small image size, low resolution; small field of view of the objective lens, single objective lens model; differences in the exposure of various panchromatic cameras cause differences in image stitching.

为克服这些不足，设计了拼接式大面阵数字航测相机。其全色模块创新性的采用单物镜、反射式四棱锥分光、四块10k×10k大面阵CCD拼接的模式，拼接后总像素高达20k×20k，解决市面上面阵数字航测相机幅面较小的问题，提供大幅面高分辨力的航测图像；含宽角(95°)、中角(75°)、常角(57°)的全色物镜及多光谱物镜各一套，其中一套多光谱物镜包括四个镜头(R、G、B、NIR)。作业时根据不同的测图应用可以进行灵活选择，解决市面上面阵数字航测相机视场较小、物镜型号单一的问题；它相对于多物镜、多CCD拼接的模式(例如DMC和UCX)，避免了因各全色物镜的差异而引起的图像拼接的差异，保证了系统成像质量的一致性。In order to overcome these shortcomings, a spliced large area array digital aerial survey camera is designed. Its panchromatic module innovatively adopts a single objective lens, reflective quadrangular pyramid light splitting, and four 10k×10k large area array CCD splicing modes. After splicing, the total pixels are as high as 20k×20k, which solves the problem of the small format of the above array digital aerial survey cameras on the market. The problem is to provide large-format and high-resolution aerial survey images; including a set of panchromatic objective lenses and multispectral objective lenses with wide angle (95°), medium angle (75°), and constant angle (57°), and one set of multispectral objective lenses The objective lens consists of four lenses (R, G, B, NIR). It can be flexibly selected according to different mapping applications during operation to solve the problems of small field of view and single objective lens model of the digital aerial survey cameras on the market; The difference in image stitching caused by the difference of each panchromatic objective lens is eliminated, and the consistency of system imaging quality is guaranteed.

本发明涉及拼接式大面阵数字航测相机的宽角(95°)全色物镜。为了实现反射式四棱锥分光、四块10k×10k大面阵CCD的拼接，宽角(95°)全色物镜的后工作距离需要≥124mm，且满足高分辨力、低畸变的要求。The invention relates to a wide-angle (95°) panchromatic objective lens of a spliced large area array digital aerial survey camera. In order to achieve reflective quadrangular pyramid beam splitting and splicing of four 10k×10k large area array CCDs, the rear working distance of the wide-angle (95°) panchromatic objective lens needs to be ≥124mm, and meet the requirements of high resolution and low distortion.

目前的宽角航测相机应用的均为对称式结构(或准对称结构)，对称式结构的前组和后组相对光阑对称，其慧差、畸变和倍率色差这三种垂轴色差自动消除；球差、像散、场曲和位置色差这四种轴向相差相互叠加。因此，在半部系统中，只须校正上述四种轴向相差即可，像差校正简单。对称式结构中的Pyccap结构由于其具有特大的视场角，而且畸变也校正的非常理想，广泛地用作航测物镜。Pyccap物镜不断改进，成像质量日益提高，几乎成为了航测物镜的唯一结构形式。The current wide-angle aerial survey cameras use symmetrical structures (or quasi-symmetrical structures). The front group and rear group of the symmetrical structure are symmetrical to the aperture, and the three vertical axis chromatic aberrations of coma, distortion and chromatic aberration of magnification are automatically eliminated. ; The four axial phase differences of spherical aberration, astigmatism, curvature of field and positional chromatic aberration are superimposed on each other. Therefore, in the half system, only the above four kinds of axial phase differences need to be corrected, and the aberration correction is simple. The Pyccap structure in the symmetrical structure is widely used as an aerial survey objective lens because of its large field of view and ideal distortion correction. The Pyccap objective lens has been continuously improved, and the imaging quality has been improved day by day, and it has almost become the only structural form of the aerial survey objective lens.

然而对称式结构无法达到如此大的后工作距离，因此并不适用于本系统。However, the symmetrical structure cannot achieve such a large rear working distance, so it is not suitable for this system.

所以为了同时实现宽角与长后工作距离的需求，宽角全色相机物镜的光学结构创新的选用了反远距式结构。但是，对于这种大视场、低畸变要求的反远式结构来说，其设计起来有很大的困难：Therefore, in order to realize the requirements of wide-angle and long working distance at the same time, the optical structure of the wide-angle panchromatic camera objective lens is innovatively selected with an anti-telephoto structure. However, for this kind of anti-telescopic structure with large field of view and low distortion requirements, it is very difficult to design:

(1)结构失对称对校正畸变的影响(1) Effect of structural asymmetry on correcting distortion

对于失对称的反远距式结构来说，为了产生一个比较大的反远比1′/f′，其前组采用负光焦度的透镜组，后组采用正光焦度的透镜组，且前组和后组分离。反远距物镜前组的1/γ₁越大，其视场角越大，视场角大，则与其有关的像差则急剧增加，尤其是畸变更为严重。For the asymmetric anti-telephoto structure, in order to produce a relatively large anti-telephoto ratio 1'/f', the front group uses a lens group with negative refractive power, and the rear group uses a lens group with positive refractive power, and The front and back groups were separated. The larger the 1/γ₁ of the front group of the inverse telephoto objective lens, the larger the field of view, and the larger the field of view, the sharper the aberrations related to it, especially the more serious distortion.

(2)大视场对像差的影响(2) Influence of large field of view on aberration

对于初级(三级)像差来说，慧差与视场的一次方成正比、像散和场曲与视场的二次方成正比，而航测相机最关心的畸变，则与视场的三次方成正比。所以，对于大视场的相机来说，校正像差，尤其是畸变，是较为困难的。For primary (tertiary) aberrations, coma is proportional to the first power of the field of view, astigmatism and field curvature are proportional to the second power of the field of view, and the distortion that aerial survey cameras are most concerned about is proportional to the square of the field of view Proportional to the third power. Therefore, for a camera with a large field of view, it is more difficult to correct aberrations, especially distortion.

(3)大视场对像面照度均匀性的影响(3) The effect of large field of view on the uniformity of illumination of the image plane

随着像方半视场角ω′的增大，轴外像点照度相对轴上像点照度按照cos⁴ω′的规律下降。With the increase of the image square half field angle ω′, the off-axis image point illuminance relative to the on-axis image point illuminance decreases according to the law of cos⁴ ω′.

(4)大视场对分辨力的影响(4) Influence of large field of view on resolution

随着视场的增大，轴外视场子午方向的极限分辨力按照cos³ω的规律递减、轴外视场弧失分辨力按照cosω的规律递减。可见，随着视场角的增大，子午方向的分辨力比弧矢方向的分辨力下降得更快些。随着极限分辨力的降低，光学系统在所需空间频率上的调制传递函数MTF也受影响，且对于大视场相机来说，一般子午MTF低于弧失MTF。As the field of view increases, the limit resolution in the meridional direction of the off-axis field of view decreases according to the law of cos³ ω, and the arc loss resolution of the off-axis field of view decreases according to the law of cos ω. It can be seen that with the increase of the field angle, the resolution in the meridional direction decreases faster than that in the sagittal direction. As the limit resolution decreases, the modulation transfer function MTF of the optical system at the required spatial frequency is also affected, and for a camera with a large field of view, the meridional MTF is generally lower than the arc-loss MTF.

发明内容Contents of the invention

本发明的技术解决问题：克服现有技术的不足，提供一种宽角和长后工作距离的航测相机全色物镜，采用反远距式的结构，同时实现大视场、长后工作距离、高分辨力与低畸变。The technical problem of the present invention is to overcome the deficiencies of the prior art, and provide a panchromatic objective lens for aerial survey cameras with a wide angle and long rear working distance, adopting an inverse telephoto structure, and at the same time realize a large field of view, long rear working distance, High resolution and low distortion.

本发明的技术解决方案：一种宽角和长后工作距离的航测相机全色物镜，采用反远距式的结构，即负正透镜分离的结构；其中负光焦度透镜组作为前组、正光焦度透镜组作为后组；所述前组由第一透镜、第二透镜和第三透镜依次组成；后组由第四透镜、第五透镜、第一双胶合透镜、光阑、三胶合透镜、第二双胶合透镜和凸平透镜依次组成；前组与后组中各组元件沿光轴依次排列。The technical solution of the present invention: a panchromatic objective lens for aerial survey cameras with a wide angle and long rear working distance, which adopts an inverse telephoto structure, that is, a structure in which the negative and positive lenses are separated; the negative focal power lens group is used as the front group, The positive refractive power lens group is used as the rear group; the front group is composed of the first lens, the second lens and the third lens; the rear group is composed of the fourth lens, the fifth lens, the first doublet lens, the aperture, the triplet The lens, the second doublet lens and the convex-planar lens are sequentially composed; the components in the front group and the rear group are arranged in sequence along the optical axis.

所述前组第二透镜的凹面为非球面。The concave surface of the second lens in the front group is aspherical.

所述后组中的第五透镜和第一双胶合透镜中的第二片透镜均为厚透镜。Both the fifth lens in the rear group and the second lens in the first doublet are thick lenses.

所述凸平透镜的第二面为平面，在所述平面镀上中心到边缘透过率不同膜，以提高像面均匀性。The second surface of the convex-flat lens is a plane, and a film with different transmittance from the center to the edge is coated on the plane to improve the uniformity of the image plane.

本发明与现有技术相比本发明具有如下优点：Compared with the prior art, the present invention has the following advantages:

(1)目前的宽角航测相机中采用物镜一般采用对称式结构，尤其是对称式结构中的Pyccap结构；本发明创新性的采用反远距式的结构，即负正透镜分离的结构，以同时实现大视场与长工作距离，其负光焦度透镜组作为前组、正光焦度透镜组作为后组。反远距式结构在提高后工作距离的同时，也降低了像方半视场角ω′(从47.34°下降至36.56°)。随着像方半视场角ω′的降低，其像面照度均匀性及轴外视场极限分辨力均大大增加，实现了高分辨力与低畸变。(1) The objective lens used in the current wide-angle aerial survey camera generally adopts a symmetrical structure, especially the Pyccap structure in the symmetrical structure; At the same time, it realizes a large field of view and a long working distance. The negative refractive power lens group is used as the front group, and the positive refractive power lens group is used as the rear group. While the anti-telephoto structure increases the rear working distance, it also reduces the image square half field of view ω′ (from 47.34° to 36.56°). With the reduction of the half-field angle ω′ of the image side, the uniformity of illumination of the image plane and the limit resolution of the off-axis field of view are greatly increased, achieving high resolution and low distortion.

(2)本发明具备长后工作距离功能，其后工作距离长达125mm，保证了像方反射式四棱锥分光、四块10k×10k大面阵CCD拼接的模式，它相对于多物镜、多CCD拼接的模式(例如DMC和UCX)，避免了因各全色物镜的差异而引起的图像拼接的差异，保证了系统成像质量的一致性。(2) The present invention possesses the function of the long rear working distance, and the subsequent working distance is as long as 125mm, which ensures the pattern of image square reflective quadrangular pyramid light splitting and four 10k×10k large area array CCD splicing. Compared with multiple objective lenses and multiple The CCD mosaic mode (such as DMC and UCX) avoids the difference of image mosaic caused by the difference of each panchromatic objective lens, and ensures the consistency of system imaging quality.

(3)本发明具备宽视场，宽视场角能够达到95°，解决了目前航测相机视场较小的问题(对于DMC数字航测相机来说，其拼接后的视场角为69°×42°，对角线视场为76.7°；对于UCX数字航测相机来说，其视场角为55°×37°，其对角线视场为63.8°)。(3) The present invention has a wide field of view, and the wide field of view can reach 95 °, which solves the problem that the field of view of the current aerial survey camera is small (for the DMC digital aerial survey camera, the field of view after splicing is 69 ° × 42°, the diagonal field of view is 76.7°; for UCX digital aerial camera, its field of view is 55°×37°, and its diagonal field of view is 63.8°).

(4)本发明还具备大的像面，其像面大小182.52mm×182.52mm、对角线长度258.12mm(DMC数字航测相机拼接后的像面大小为165.89mm×92.16mm；UCX数字航测相机面阵尺寸为104mm×68.4mm)。如此大的像面，满足四块10k×10k大面阵CCD拼接的模式，即可提供总像素为20k×20k的大幅面高分辨力的航测图像。(4) The present invention also has a large image plane, the size of which is 182.52mm × 182.52mm, and the length of the diagonal line is 258.12mm (the size of the image plane after splicing of DMC digital aerial survey cameras is 165.89mm × 92.16mm; UCX digital aerial survey camera The area array size is 104mm×68.4mm). Such a large image area satisfies the mosaic mode of four 10k×10k large area array CCDs, which can provide a large-format and high-resolution aerial survey image with a total pixel size of 20k×20k.

(5)本发明在满足高分辨力与低畸变要求的同时，还解决了像面照度不均匀性的问题。(5) While satisfying the requirements of high resolution and low distortion, the present invention also solves the problem of non-uniform illumination of the image plane.

附图说明Description of drawings

图1为本发明宽角与长后工作距离航测相机全色物镜结构示意图；Fig. 1 is a schematic structural view of the panchromatic objective lens of the wide-angle and long-back working distance aerial survey camera of the present invention;

图2为本发明宽角与长后工作距离航测相机全色物镜MTF图；Fig. 2 is the MTF diagram of the panchromatic objective lens of the wide-angle and long working distance aerial survey camera of the present invention;

图3为本发明宽角与长后工作距离航测相机全色物镜点列图；Fig. 3 is a panchromatic objective lens point diagram of the wide-angle and long-back working distance aerial survey camera of the present invention;

图4为本发明宽角与长后工作距离航测相机全色物镜球差、场曲、畸变图。Fig. 4 is a diagram of spherical aberration, field curvature and distortion of the panchromatic objective lens of the wide-angle and long working distance aerial survey camera of the present invention.

具体实施方式Detailed ways

本发明主要参数为：波段480nm～700nm；像面大小182.52mm×182.52mm、对角线长度258.12mm；焦距f：118.93mm；F#8；视场ω：94.68°；反远比1′/f′＝1.051；镜筒长度：336.5mm；后截距：125mm；第一面通光口径：215.2mm。55lp/mm处MTF≥0.363、轴外像面照度43.8％；各视场弥散斑大小为像元(9μm)量级；相对畸变小于0.011％，绝对畸变小于12.86μm。The main parameters of the present invention are: wave band 480nm～700nm; image plane size 182.52mm×182.52mm, diagonal length 258.12mm; focal length f: 118.93mm;F#8; field of view ω: 94.68°; f'=1.051; lens barrel length: 336.5mm; back intercept: 125mm; first surface aperture: 215.2mm. The MTF at 55lp/mm is ≥0.363, and the off-axis image plane illumination is 43.8%; the size of the diffuse spots in each field of view is on the order of a pixel (9μm); the relative distortion is less than 0.011%, and the absolute distortion is less than 12.86μm.

如图1所示，为了同时实现宽角与长工作距离，本发明的光学结构创新性的采用反远距式的结构，即负正透镜分离的结构。其负光焦度透镜组作为前组、正光焦度透镜组作为后组。因本发明的焦距f′＝118.93mm，其后工作距离1′＝125mm，所以其反远比1′/f′＝1.051。反远距式结构固然在校正像差，尤其是校正畸变上要困难很多，但也有它固有的优点：它在提高后工作距离的同时，也降低了像方半视场角ω′(从47.34°下降至36.56°)。随着像方半视场角ω′的降低，其像面照度均匀性及轴外视场极限分辨力均大大增加。As shown in Figure 1, in order to achieve wide angle and long working distance at the same time, the optical structure of the present invention innovatively adopts an inverse telephoto structure, that is, a structure in which negative and positive lenses are separated. The negative focal power lens group is used as the front group, and the positive refractive power lens group is used as the rear group. Because the focal length of the present invention is f'=118.93mm, and the subsequent working distance 1'=125mm, the inverse telephoto ratio 1'/f'=1.051. Although the anti-telephoto structure is much more difficult to correct aberrations, especially distortions, it also has its inherent advantages: while increasing the rear working distance, it also reduces the image square half-field angle ω′ (from 47.34 ° down to 36.56°). With the reduction of the image half angle of view ω′, the uniformity of the illumination of the image plane and the limit resolution of the off-axis field of view are greatly increased.

前组由第一透镜1、第二透镜2、第三透镜3依次组成；后组由第四透镜4、第五透镜5、第一双胶合透镜6、光阑7、三胶合透镜8、第二双胶合透镜9和凸平透镜10依次组成。前组与后组各元件沿光轴依次排列。前组总焦距为-70mm左右，第一透镜1通光口径为215.2mm。The front group consists of the first lens 1, thesecond lens 2, and thethird lens 3; the rear group consists of thefourth lens 4, thefifth lens 5, the first doublet lens 6, the stop 7, thetriplet lens 8, the second Two doublet lenses 9 and a convex-planar lens 10 are formed sequentially. The elements of the front group and the rear group are arranged in sequence along the optical axis. The total focal length of the front group is about -70mm, and the aperture of the first lens 1 is 215.2mm.

前组由第一透镜1、第二透镜2和第三透镜3组成，采用三片负透镜分离的结构，用来分担前组大的负光焦度，避免面型的过度弯曲、降低镜头的敏感性、减少高级像差。The front group is composed of the first lens 1, thesecond lens 2 and thethird lens 3. It adopts the structure of three negative lenses separated, which is used to share the large negative power of the front group, avoid excessive curvature of the surface shape, and reduce the loss of the lens. Sensitivity, reduction of advanced aberrations.

考虑到反远距式结构在校正整个系统畸变的前提下，难以兼顾轴外像差的校正，从而导致轴外视场分辨力的下降。为了兼顾轴外视场的像差与系统畸变的校正，在前组引入非球面。为校正轴外像差，非球面的最佳位置在第一透镜1的凸面上。然而，因为第一透镜1的通光口径比较大，这必然导致在非球面检测时所用的补偿镜的增大及复杂化，增加成本且难以检测。为了降低检测非球面时所用补偿镜的口径，本发明决定将非球面用于第二透镜二的凹面上，虽然校正轴外像差的效果相对来说逊色一些，但其优点在于相对的降低了加工和检测非球面时的难度和成本。透镜2凹面的F数(即半径与口径之比)约为0.7，采用8次非球面。Considering that the anti-telephoto structure corrects the distortion of the entire system, it is difficult to take into account the correction of off-axis aberrations, resulting in a decrease in the resolution of the off-axis field of view. In order to take into account the correction of the aberration of the off-axis field of view and the system distortion, an aspheric surface is introduced in the front group. To correct off-axis aberrations, the best position of the aspheric surface is on the convex surface of the first lens 1 . However, because the light aperture of the first lens 1 is relatively large, this will inevitably lead to the increase and complexity of the compensation mirror used in the aspheric surface detection, which increases the cost and makes the detection difficult. In order to reduce the caliber of the compensating mirror used when detecting the aspheric surface, the present invention decides to use the aspheric surface on the concave surface of thesecond lens 2. Although the effect of correcting off-axis aberration is relatively weak, its advantage is that it relatively reduces the Difficulty and cost when machining and inspecting aspheric surfaces. The F-number (that is, the ratio of the radius to the aperture) of the concave surface of thelens 2 is about 0.7, and an 8th degree aspheric surface is used.

后组由第四透镜4、第五透镜5、第一双胶合透镜6、光阑7、三胶合透镜8、第二双胶合透镜9、凸平透镜10组成。为了产生大的反远比，反远距式物镜的前组残留的畸变比较严重，所以需要优化后组，以产生符号相反的畸变加以补偿。后组总焦距为87mm左右。光阑7口径小于21.5mm。The rear group is composed of thefourth lens 4 , thefifth lens 5 , the first doublet lens 6 , the stop 7 , thetriplet lens 8 , the second doublet lens 9 , and the convex-planar lens 10 . In order to produce a large anti-telephoto ratio, the residual distortion of the front group of the anti-telephoto objective lens is relatively serious, so it is necessary to optimize the rear group to produce distortions with opposite signs to compensate. The total focal length of the rear group is about 87mm. The diameter of aperture 7 is smaller than 21.5mm.

在像差校正的同时，为了缩短相机的结构尺寸，后组使用了厚透镜(厚透镜为本领域通用术语)，使光线相比在空气中能够更快的收敛。由图1可见，第五透镜5和第一双胶合透镜6的第二片透镜均比较厚，本实施例分别为55mm和35mm左右。具体的厚度本领技术人员可以根据后组透镜的大小来很容易确定，上面数据只是为了说明。At the same time of aberration correction, in order to shorten the structural size of the camera, the rear group uses a thick lens (thick lens is a general term in this field), so that the light can converge faster than in the air. It can be seen from FIG. 1 that both thefifth lens 5 and the second lens of the first doublet lens 6 are relatively thick, about 55mm and 35mm respectively in this embodiment. The specific thickness can be easily determined by those skilled in the art according to the size of the rear lens group, and the above data are only for illustration.

在校正相机畸变的同时，为了保证其大的后截距，光学设计软件倾向于将光阑7后方的透镜在结构上进行压缩。因此，可以将光阑后面的部分尽量做成胶合镜，缩短光阑7后方镜组的长度且保证各透镜的厚度。因此本发明中光阑7后的透镜选用三胶合透镜和双胶合透镜，即图1中的三胶合透镜8和双胶合透镜9。While correcting the camera distortion, in order to ensure its large back focus, the optical design software tends to compress the lens behind the diaphragm 7 structurally. Therefore, the part behind the diaphragm can be made into a doublet as much as possible, shortening the length of the lens group behind the diaphragm 7 and ensuring the thickness of each lens. Therefore, the lens behind the diaphragm 7 in the present invention selects a triplet lens and a doublet lens, namely thetriplet lens 8 and the doublet lens 9 in Fig. 1 .

在设计时，已通过降低像方半视场角ω′的方法部分的提高了像面照度的均匀性，但为了更进一步提高像面照度均匀性，可用中心到边缘透过率不同的滤光片。若加在第一透镜1之前，因为第一透镜1大的通光口径和大的视场，其滤光片口径极大，与航测相机的小型化要求相悖。所以，将凸平透镜10的第二面设计成平面，可以镀上中心到边缘透过率不同膜，以提高像面均匀性。During the design, the uniformity of the image plane illumination has been partially improved by reducing the image half angle of view ω′, but in order to further improve the uniformity of the image plane illumination, filters with different transmittances from the center to the edge can be used piece. If it is added before the first lens 1, because of the large aperture and large field of view of the first lens 1, the aperture of the filter is very large, which is contrary to the miniaturization requirement of the aerial survey camera. Therefore, if the second surface of the convex-planar lens 10 is designed to be flat, a film with different transmittance from the center to the edge can be coated to improve the uniformity of the image plane.

在后组之后，还有反射式四棱锥用来分光，以及四块大面阵10K×10K的CCD。因为反射式四棱锥的各面均为反射面，对光程不产生影响，所以并没有在图1中显示出来。四块CCD用等效大小的CCD保护玻璃11及像面12表示。After the rear group, there are reflective quadrangular pyramids for light splitting, and four large area array 10K×10K CCDs. Because each surface of the reflective quadrangular pyramid is a reflective surface, which does not affect the optical path, it is not shown in Figure 1. Four CCDs are represented by CCDprotective glass 11 andimage plane 12 of equivalent size.

图2为宽角全色物镜MTF图，其各视场的像面相对照度及55lp/mm处的调制传递函数MTF见表1。如表1所示，宽角全色物镜轴外像面照度为43.8％(未镀中心和边缘透过率不同的膜之前)，55lp/mm处MTF≥0.363。Figure 2 is the MTF diagram of the wide-angle panchromatic objective lens, and the relative illuminance of the image plane of each field of view and the modulation transfer function MTF at 55lp/mm are shown in Table 1. As shown in Table 1, the off-axis image plane illuminance of the wide-angle panchromatic objective lens is 43.8% (before the film with different center and edge transmittances is not coated), and the MTF at 55 lp/mm is ≥ 0.363.

表1 各视场像面相对照度(未镀膜之前)及MTF值Table 1 The relative illuminance (before coating) and MTF value of the image plane in each field of view

  物方半视场ωobject side half field ω  0°0°  14.202°14.202°  23.67°23.67°  33.469°33.469°  40.239°40.239°  47.34°47.34°  像面相对照度(％)Relative illuminance of image surface (%)  100100  94.494.4  84.984.9  71.171.1  58.758.7  43.843.8  子午MTF(55lp/mm)Meridian MTF(55lp/mm)  0.5060.506  0.4870.487  0.4550.455  0.3860.386  0.3630.363  0.3630.363  弧失MTF(55lp/mm)Arc loss MTF(55lp/mm)  0.5060.506  0.5210.521  0.5360.536  0.5510.551  0.5180.518  0.4980.498

图3为本发明宽角和长后工作距离航测相机全色物镜点列图，其各视场RMS直径如表2所示，各视场弥散斑大小为像元(9μm)量级。Fig. 3 is a panchromatic objective lens spot diagram of the wide-angle and long working distance aerial survey camera of the present invention, the RMS diameter of each field of view is shown in Table 2, and the size of the diffuse spot of each field of view is on the order of a pixel (9 μm).

表2 各视场RMS直径Table 2 RMS diameter of each field of view

  物方半视场ωobject side half field ω  0°0°  14.202°14.202°  23.67°23.67°  33.469°33.469°  40.239°40.239°  47.34°47.34°

  RMS直径(μm)RMS diameter (μm)  8.698.69  8.558.55  10.3210.32  11.6711.67  11.3211.32  9.919.91

图4为本发明宽角和长后工作距离航测相机全色物镜的球差、场曲、畸变图。其中，畸变为航空测绘相机最重要的指标之一，各视场的相对畸变及绝对畸变设计值见表3，宽角全色相机物镜的相对畸变小于0.011％，绝对畸变小于12.86μm。Fig. 4 is a diagram of spherical aberration, field curvature and distortion of the panchromatic objective lens of the wide-angle and long-back working distance aerial survey camera of the present invention. Among them, distortion is one of the most important indicators of aerial surveying and mapping cameras. The relative distortion and absolute distortion design values of each field of view are shown in Table 3. The relative distortion of the wide-angle panchromatic camera objective lens is less than 0.011%, and the absolute distortion is less than 12.86μm.

表3 各视场畸变数据Table 3 Distortion data of each field of view

Claims (4)

1. the panchromatic object lens of aviation measuring camera of wide angle and long back work distance, it is characterized in that: described object lens adopt the structure of anti-long distance formula, promptly negative positive lens separated structures; Wherein the negative power lens combination as preceding group, positive light coke lens combination as the back group; Group is made of successively first lens (1), second lens (2) and the 3rd lens (3) before described; The back group is made of successively the 4th lens (4), the 5th lens (5), first cemented doublet (6), diaphragm (7), three balsaming lenss (8), second cemented doublet (9) and protruding plano lens (10); Each set of pieces was arranged in order along optical axis during preceding group was organized with the back.

2. the panchromatic object lens of aviation measuring camera of wide angle according to claim 1 and long back work distance is characterized in that: the concave surface of group second lens (2) is an aspheric surface before described.

3. the panchromatic object lens of aviation measuring camera of wide angle according to claim 1 and long back work distance is characterized in that: the 5th lens (5) in the group of described back and second lens in first cemented doublet (6) are thick lens.

4. the panchromatic object lens of aviation measuring camera of wide angle according to claim 1 and long back work distance is characterized in that: second of described protruding plano lens (10) is the plane, and the center that plates on described plane is to the different films of edge transmitance, to improve the image planes homogeneity.

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