Unit cell selection verification systems and methods
Techniques for facilitating unit cell selection verification systems and methods are provided. In one example, a method includes detecting, by each detector of a focal plane array (FPA), electromagnetic radiation. Each detector is selectively coupled to a readout circuit of the FPA via a selection circuit of the FPA. The method further includes, during a frame period, applying a predetermined signal pattern to a portion of the selection circuit, where the portion is associated with a subset of detectors of the FPA, and performing a readout of the FPA to obtain a respective output signal associated with each respective detector of the FPA. The method further includes determining whether the portion of the selection circuit is operating properly based at least on the output signal associated with the detectors of the subset from the readout. Related systems and devices are also provided.
1. A method comprising:
detecting, by each detector of a focal plane array, electromagnetic radiation, wherein each detector is selectively coupled to a readout circuit of the focal plane array via a selection circuit of the focal plane array;
during a first frame period:
applying a first predetermined signal pattern to a first portion of the selection circuit, wherein the first portion of the selection circuit is associated with a first subset of detectors of the focal plane array; and
performing a first readout of the focal plane array to obtain a respective output signal associated with each respective detector of the focal plane array;
determining whether the first portion of the selection circuit is operating properly based at least on the output signal associated with the detectors of the first subset from the first readout; and
generating an image based at least on the output signals of the detectors of the focal plane array not among the first subset of detectors.
2. The method of claim 1 , wherein the first predetermined signal pattern is one of a plurality of predetermined signal patterns, and wherein the output signal of each detector among the first subset in response to at least one of the plurality of predetermined signal patterns is independent of the electromagnetic radiation.
3. The method of claim 2 , wherein the determining is based on the output signal of the detectors of the first subset in response to each of the plurality of predetermined signal patterns.
4. The method of claim 1 , wherein the focal plane array comprises a unit cell array, wherein each unit cell of the unit cell array comprises a detector of the focal plane array and a portion of the selection circuit, wherein the portion comprises a plurality of switches, and wherein the first subset of detectors comprises a row of detectors.
5. The method of claim 1 , further comprising, during a second frame period:
applying a second predetermined signal pattern to the first portion of the selection circuit; and
performing a second readout of the focal plane array to obtain a respective output signal associated with each respective detector of the focal plane array,
wherein the determining is based at least on the output signals associated with the detectors of the first subset from the first and second readouts.
6. The method of claim 5 , wherein the second frame period is temporally adjacent to the first frame period.
7. The method of claim 5 , wherein the second frame period is not temporally adjacent to the first frame period.
8. The method of claim 1 , further comprising, during a second frame period:
applying a second predetermined signal pattern to a second portion of the selection circuit, wherein the second portion of the selection circuit is associated with a second subset of detectors of the focal plane array;
performing a second readout of the focal plane array to obtain a respective output signal associated with each respective detector of the focal plane array; and
determining whether the second portion of the selection circuit is operating properly based at least on the output signals associated with the detectors of the second subset from the second readout, and wherein the second frame period is temporally adjacent to the first frame period.
9. The method of claim 1 , further comprising determining pixel values for the first subset of detectors based on the output signal of one or more of the detectors not among the first subset of detectors, wherein the image is based on the pixel values and the output signals of the detectors not among the first subset of detectors.
10. The method of claim 9 , wherein the one or more of the detectors comprise one or more detectors neighboring one or more detectors of the first subset of detectors.
11. The method of claim 1 , further comprising, during the first frame period:
configuring a first plurality of switches to selectively short one or more of the detectors of the focal plane array;
configuring a second plurality of switches to selectively provide a bias signal to one or more of the detectors of the focal plane array; and
configuring a third plurality of switches to selectively couple one or more of the detectors of the focal plane array to the readout circuit.
12. The method of claim 11 , wherein:
the first predetermined signal pattern comprises a first signal level associated with a first control signal, a second signal level associated with a second control signal, and a third signal level associated with a third control signal;
the configuring the first plurality of switches comprises configuring a first set of switches associated with the first subset of detectors using the first control signal;
the configuring the second plurality of switches comprises configuring a second set of switches associated with the first subset of detectors using the second control signal; and
the configuring the third plurality of switches comprises configuring a third set of switches associated with the first subset of detectors using the third control signal.
13. The method of claim 11 , wherein each switch of the first plurality of switches, each switch of the second plurality of switches, and each switch of the third plurality of switches comprises a transistor.
14. An imaging device comprising:
a focal plane array comprising:
a detector array comprising a plurality of detectors, wherein each detector is configured to detect electromagnetic radiation;
a readout circuit configured to perform, during a first frame period, a first readout to obtain a respective output signal associated with each respective detector of the detector array; and
a selection circuit configured to selectively couple the detector array to the readout circuit;
a control signal generator configured to apply, during the first frame period, a first predetermined signal pattern to a first portion of the selection circuit, wherein the first portion of the selection circuit is associated with a first subset of detectors of the detector array;
a verification device configured to determine whether the first portion of the selection circuit is operating properly based at least on the output signal associated with the detectors of the first subset from the first readout; and
an image processing device configured to generate an image based at least on the output signals of the detectors of the detector array not among the first subset of detectors.
15. The imaging device of claim 14 , wherein the first predetermined signal pattern is one of a plurality of predetermined signal patterns, and wherein the verification device is configured to determine whether the first portion of the selection circuit is operating properly based on the output signals of the detectors of the first subset in response to each of the plurality of predetermined signal patterns.
16. The imaging device of claim 14 , wherein the focal plane array comprises a unit cell array, wherein each unit cell of the unit cell array comprises a detector of the detector array and a portion of the selection circuit, and wherein the portion comprises a plurality of switches.
17. The imaging device of claim 14 , wherein:
the control signal generator is further configured to apply, during a second frame period, a second predetermined signal pattern to the first portion of the selection circuit;
the readout circuit is further configured to perform, during the second frame period, a second readout to obtain a respective output signal associated with each respective detector of the detector array; and
the verification device is configured to determine whether the first portion of the selection circuit is operating properly based at least on the output signal associated with the detectors of the first subset from the first and second readouts.
18. The imaging device of claim 14 , wherein:
the control signal generator is further configured to apply, during a second frame period, a second predetermined signal pattern to a second portion of the selection circuit, wherein the second portion of the selection circuit is associated with a second subset of detectors of the detector array;
the readout circuit is further configured to perform, during the second frame period, a second readout to obtain a respective output signal associated with each respective detector of the detector array; and
the verification device is further configured to determine whether the second portion of the selection circuit is operating properly based at least on the output signal associated with the detectors of the second subset from the second readout.
19. The imaging device of claim 14 , wherein the image processing device is further configured to determine pixel values for the first subset of detectors based on the output signal of one or more of the detectors not among the first subset of detectors, and wherein the image is based on the pixel values and the output signals of the detectors not among the first subset of detectors.
20. The imaging device of claim 14 , wherein the selection circuit comprises:
a first plurality of transistors, wherein each transistor of the first plurality is configured to selectively short a respective one of the plurality of detectors;
a second plurality of transistors, wherein each transistor of the second plurality is configured to selectively provide a bias signal to a respective one of the plurality of detectors; and
a third plurality of transistors, wherein each switch of the third plurality is configured to selectively couple a respective one of the plurality of detectors to the readout circuit; wherein:
the first predetermined signal pattern comprises a first signal level associated with a first control signal, a second signal level associated with a second control signal, and a third signal level associated with a third control signal;
the first plurality of transistors comprises a first set of transistors associated with the first subset of detectors;
the second plurality of transistors comprises a second set of transistors associated with the first subset of detectors;
the third plurality of transistors comprises a third set of transistors associated with the first subset of detectors;
during the first frame period:
the first set of transistors is configured to receive the first control signal;
the second set of transistors is configured to receive the second control signal; and
the third set of transistors is configured to receive the third control signal.