In order to meet volume requirement and provide high image quality for a Long Range Oblique Photography (LOROP)
system, we adopted Cassegrain-type telescope with lens compensators for the operation in both regions of 0.6 ~ 0.9 μm
(EO channel) and 3.7 ~ 4.8 μm (IR channel). To provide dual-band functionality, the tilted plane-parallel plate is applied
and acts as a beam splitter located in the space between primary and secondary mirrors. The system is near to telecentric
in detector space (EO) and telecentric in intermediate image space (IR). The telecentricity provides image height
constancy while adjusting the focus. The optical system includes Back Scan Mechanism (BSM) to compensate image
blurring for integration time.