To solve the problem in which the contrast between a space target and its background is too low to be distinguished in a dark scene, the focal-plane array polarization imaging system is used to image the outdoor dark scene and the indoor space simulation environment. At the same time, to compensate for the shortcomings of the decreased resolution of the focal-plane array polarization imaging system, the bicubic interpolation algorithm is used for upsampling. On one hand, the intensity image under four different polarization angles can be obtained by a single exposure of the focal-plane array polarizer camera, then, the Degree of Polarization (DOP) and the Angle of Polarization (AOP) images are compared to the intensity image. On the other hand, the bicubic interpolation algorithm is used to upsample the four intensity images to improve the image resolution and then, calculate the DOP image compared with the DOP image obtained without the upsampling procedure. The experimental results show that compared with traditional intensity imaging, the contrast of the target is improved, the edge information and texture information are better displayed by imaging polarimetry, and the final imaging resolution is improved by the bicubic interpolation algorithm. The measure of enhancement (EME), a contrast evaluation index, is approximately 17% more in the DOP image than in the intensity image, proving that the focal plane polarization imaging system using a bicubic interpolation algorithm has potential application value for the identification of space targets in the dark scenes.