Thermal control and temperature uniformity are important factors for space remote sensing cameras. This paper describes the problems with existing systems and introduces the thermal design of a space optical remote sensing camera. Firstly, based on the theory of wave-front aberration distribution, the thermal control index of a space remote sensing camera is proposed. Then on the basis of the analysis of the heat flux environment outside the camera space, the thermal optical analysis of the camera is performed by using the finite element analysis method at high and low temperature conditions. The results show that the transfer function of the optical system with the resolution of 50 lp in the full field of view is more than 0.4. The optical design index can be satisfied, and the rationality of the thermal design is verified. The simulation result meets the requirements of optical design very well. Therefore the study in this paper can be used as an important reference for other space optical systems, which has certain engineering significance.
In combination of the advantages of the optical encryption technology and optical hiding technology, this paper is going
to reveal the way of hiding the encrypted result obtained from scrambling technology in the low-frequency coefficients
of secondary discrete wavelet transform domain of another public image. Meanwhile, the information in different pixels
is hidden by different coefficient matrixes generated by chaos technology in the hiding process. It makes the encrypted
result more difficult to decipher. The proposed method is proved to be a valid approach for hiding the confidential
information as secret image in another non-confidential image via computer simulation and validation. The quality
decline of the carrier image is unapparent, which is unlikely to cause the attackers' attention. This method can effectively
resist the influence of noise, cutting, compression and other attacks. What’s more, the broad key space and good
robustness are of high practical value.