Arnold C. Goldberg

Flexible readout and integration sensor (FRIS): a bio-inspired, system-on-chip, event-based readout architecture

We present a bio-inspired system-on-chip focal plane readout architecture which at the system level, relies on an event based sampling scheme where only pixels within a programmable range of photon flux rates are output. At the pixel level, a one bit oversampled analog-to-digital converter together with a decimator allows for the quantization of signals up to 26 bits. Furthermore, digital non-uniformity correction of both gain and offset errors is applied at the pixel level prior to readout. We report test results for a prototype array fabricated in a standard 90nm CMOS process. Tests performed at room and cryogenic temperatures demonstrate the capability to operate at a temporal noise ratio as low as 1.5, an electron well capacity over 100Ge-, and an ADC LSB down to 1e-.

A bio-inspired event-driven digital readout architecture with pixel-level A/D conversion and non-uniformity correction

We present a bio-inspired readout integrated circuit (ROIC) for visible and infrared image sensors. At the system level, the architecture relies on an event based readout scheme where only pixels within a programmable range of photon flux rates are output. At the pixel level, a one bit oversampled analogto-digital converter together with a decimator allows for the quantization of signals up to 26 bits. Furthermore, digital non-uniformity correction of both gain and offset errors is applied at the pixel level prior to readout. We present results from a prototype 126×128 array fabricated in a standard 90nm CMOS process.

High-performance, event-driven, low-cost, and SWaP imaging sensor for hostile fire detection, homeland protection, and border security

The advanced imagers team at JHU APL and ECE has been advocating and developing a new class of sensor systems that address key system level performance bottlenecks but are sufficiently flexible to allow optimization of associated cost and size, weight, and power (SWaP) for different applications and missions. A primary component of this approach is the innovative system-on-chip architecture: Flexible Readout and Integration Sensors (FRIS). This paper reports on the development and testing of a prototype based on the FRIS concept. It will include the architecture, a summary of test results to date relevant to the hostile fire detection challenge. For this application, this prototype demonstrates the potential for this concept to yield the smallest SWaP and lowest cost imaging solution with a low false alarm rate. In addition, a specific solution based on the visible band is proposed. Similar performance and SWaP gains are expected for other wavebands such as SWIR, MWIR, and LWIR and/or other applications like persistent surveillance for critical infrastructure and border control in addition to unattended sensors.

Characterizing optical properties of disturbed surface signatures

The burial of objects disturbs the ground surface in visually perceptible ways. This project investigated how such information can inform detection via imaging from visible through mid-infrared wavelengths. Images of the ground surface where objects were buried were collected at multiple visible through mid-infrared wavelengths prior to burial and afterward at intervals spanning approximately two weeks. Signs of soil disturbed by emplacement change over time and exposure in the natural environment and vary in salience across wavelengths for different time periods. Transient cues related to soil moisture or illumination angle can make signatures extraordinarily salient under certain conditions. Longpass shortwave infrared and multi-band mid-infrared imaging can enhance the signature of disturbed soils over visible imaging. These findings add knowledge and understanding of how soil disturbances phenomena can be exploited to aid detection.

Compact midwave imaging system (CMIS) for weather satellite applications

The Johns Hopkins University Applied Physics Laboratory (JHU/APL) has created a unique design for a compact, lightweight, and low-power instrument called the Compact Midwave Imaging Sensor (CMIS). Funded by the NASA ESTO Instrument Incubator Program (IIP), the goal of this CMIS development project is to increase the technical readiness of CMIS for retrieval of cloud heights and atmospheric motion vectors using stereo-photometric methods. The low-cost, low size, weight and power (SWaP) CMIS solution will include high operating temperature (HOT) MWIR detectors and a very low power cooler to enable spaceflight in a 6U CubeSat. This paper will provide an overview of the CMIS project to include the high-level sensor design.

Compact midwave imaging system (CMIS) for retrieval of cloud motion vectors (CMVs) and cloud geometric heights (CGHs)

The Johns Hopkins University Applied Physics Laboratory (JHU/APL) is developing a compact, light-weight, and lowpower midwave-infrared (MWIR) imager called the Compact Midwave Imaging Sensor (CMIS), under the support of the NASA Earth Science Technology Office Instrument Incubator Program. The goal of this CMIS instrument development and demonstration project is to increase the technical readiness of CMIS, a multi-spectral sensor capable of retrieving 3D winds and cloud heights 24/7, for a space mission. The CMIS instrument employs an advanced MWIR detector that requires less cooling than traditional technologies and thus permits a compact, low-power design, which enables accommodation on small spacecraft such as CubeSats. CMIS provides the critical midwave component of a multi-spectral sensor suite that includes a high-resolution Day-Night Band and a longwave infrared (LWIR) imager to provide global cloud characterization and theater weather imagery. In this presentation, an overview of the CMIS project, including the high-level sensor design, the concept of operations, and measurement capability will be presented. System performance for a variety of different scenes generated by a cloud resolving model (CRM) will also be discussed.