16.5 Calibration and Special Testing
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Table 16.7 Implementation methods for instrument function and performance
Instrument
Function
requirement
Performance
requirement
Implementation methods
in design and development
Descent camera
To continuously obtain
lunar surface image of
landing site during
powered descent
Band range
It was achieved by spectral
of lens coating and
spectral of detector
Normal imaging distance When the optical lens was
designed, the best imaging
distance was determined
with the larger F number
and other means to make
the camera depth meet the
requirement
Effective pixels number
It was achieved by
selection of detector that
met the requirement
FoV
It was achieved by optical
design. In the optical lens
calibration test, the focal
length should be controlled
in certain accuracy range
Frame frequency
It was achieved by
selection of detector which
met the frame frequency
requirement. The exposure
time and image
compression time should
be designed reasonably
Quantitative value
It was achieved by
selection of detector that
met the requirement
MTF
In optical design, the
optical system should
achieve the diffraction
limit imaging quality. The
lens shape accuracy and
central thickness error
should be controlled. In
optical lens assembly, the
lens interval should be
adjusted to ensure the
optical imaging quality
(continued)