Our Research
 We proposed a novel detector array for detecting and localizing
particleemitting sources, whose configuration is inspired by the biological
compound eye but generalizes it. The array consists of multiple "eyelets"
(similar to ommatidia), each having a conical module with a lens on its top and
an inner subarray containing a large number of small particle detectors.
 The
eyelets can be used to detect uncharged particles such as photons and neutrons.
The proposed array combines the advantages of the biological compound eye (large FOV) and of human
eyes (high spatial resolution). Moreover, the size of the array is
compact compared with other distributed sensor arrays.

Fig. 2: The compoundeyeinspired particle detector array.


We derived a rigorous general
mathematical model for the proposed array by rigorously defining several basis
concepts and assumptions, proposing a basis function presentation for the
array's transfer function, and optimizing that basis.
 We analyzed the array
performance by computing statistical CramerRao bounds (CRBs) on
the errors in estimating the direction of arrival of the incident
particles, deriving a lower bound on the meansquare angular error
(MSAE) of source localization for a specific array, introducing a
universal lower bound on the MSAE for an arbitrary spherical array
in principle, and investigating the MSAE of two source direction
estimators.
 We numerically compare the performance of the
proposed array with the biological compound eye, optimally design
the array configuration, show that both source direction estimators
can asymptotically attain the performance bound, and analyze the
hardware efficiency by comparing the two MSAE bounds.
 Potential applications include artificial vision in medicine (e.g.,
artificial eye for the blind) or robotics (e.g., for industry or
space missions), astronomy (e.g., for remote stars), security (e.g.,
for nuclear materials), and particle communications.

Fig. 3: Comparison of source localization accuracy between the biological compound eye and the proposed
array.
Left: The compound eye, Right: The proposed array.

References
 A. Nehorai, Z. Liu, and E.
Paldi, "Optimal design of a generalized compound eye particle detector array,"
Proc. SPIE Vol. 6232, Intelligent Integrated Microsystems, 62320O, 14
pages, Orlando, FL, Apr 2006.

Z. Liu, A. Nehorai, and E. Paldi, "Statistical analysis of a generalized
compound eye detector array," Proc. 4th IEEE Sensor Conference, 4 pages,
Irvine, CA, OctNov 2005.

Z. Liu, A. Nehorai, and E. Paldi,
"A biologically inspired compoundeye detector array: part I  modeling and fundamental limits,"
in revision for
IEEE Trans. on Signal Processing.

Z. Liu, A. Nehorai, and E. Paldi,
"A biologically inspired compoundeye detector array: part II  statistical performance analysis,"
in revision for
IEEE Trans. on Signal Processing.
