| Popis: |
This paper introduces the working principles of Line-Matrix CCD(LMCCD) mapping cameras firstly and points out that the key step to realize the LMCCD camera is to develop focal plane modules.Some pivotal techniques used in the reality process of a LMCCD mapping space camera are introduced,such as stitching line and matrix CCDs together on an image base board in high precision,designing elements in high density and very low noise,controlling dark noises related to the temperature and the heat produced by the CCD under a vacuum environment,assembling the circuit board and the focal plane and soldering the CCD.Finally,it gives developing and experimental results of the LMCCD mapping camera.The results show that the stitching precision of line and matrix CCDs in coplanarity is better than 5 μm,and both the amounts of moving and parallelism are better than 2 μm.The Signal to Noise ratio(SNR) tested in laboratory is better than 90 under a typical working condition(the solar incidence angle is 30° and the reflectivity of the earth's surface is 0.3).Furthermore,the temperature of the focal plane module can be controlled under 30℃ in a working period of 15 min.All of these results satisfy the requirements of the LMCCD for the CCD stitching,temperature control and the SNR. |
