Assume that the length of temporal
subaperture (also called time-smoothing factor) is M (M < K).
In conventional 1D array transducer, a subset of transducer elements or
subaperture is sequentially selected to send an acoustic beam perpendicularly to the transducer surface, and one line is drawn at the same time.
The D3-STAP does not require the training data at the cost of reduced
subaperture. The performance of D3-STAP declines because its system DOF decreases.
Prats, "First ENVISAT and ERS-2 parasitic bistatic fixed receiver SAR images processed with the
subaperture range-Doppler algorithm," IGARSS, 1840-1843, 2006.
To keep pace with ever more stringent accuracy requirements of modern optics manufacturing, QED Technologies, Rochester, N.Y., has developed the
Subaperture Stitching Interferometer for Aspheres (SSI-A), a six-axis, computer-controlled interferometric workstation that marks a first in the optics industry.
The MR fluid is delivered to the rotating wheel, pulled against the wheel's velocity and becomes a
subaperture polishing tool.
Its unique optical design utilizes a
subaperture meniscus corrector lens in front of the secondary mirror to produce a large imaging field free from optical aberrations at f/11.5.
Because the speckles distribute randomly, they can be restrained by the non-coherent accumulation of multiple
subaperture images.
The other way using a
subaperture approach [13, 14] is proposed, but the general section principle cannot be confirmed well.
Two methods are available to account for this problem, including the method of
subaperture [5] and the method of ANCS.
Compared to other solutions to overcome the aliased Doppler spectra, the use of
subaperture is a simple and efficient method.