Size, Weight, And Power Research Articles

Hyperspectral Image Classification via Compressive Sensing

Although hyperspectral technology has continued to improve over the years, it is still limited to size, weight, and power (SWaP) constraints. One major issue is the need to sample a large number of very fine spectral bands. Such prohibitively large size of hyperpsectral data creates challenges in both data archival and processing. Compressive sensing (CS) is an enabling technology for reducing the overall data processing and SWaP requirements. This paper explores the viability of performing classification for hyperspectral data on a compressively sensed band domain (CSBD) via CS instead of the original data space, without performing sparse reconstruction. In particular, the well-known restricted isometry property (RIP) and a random spectral sampling strategy are explored for hyperspectral image classification (HSIC) in CSBD. A mathematical analysis is also presented to show that the classification error can be expressed in terms of the restricted isometry constant (RIC) so that the HSIC in the original full-band data space can be achieved in CSBD provided that sufficient band-sensing conditions are met. To validate the proposed CS-HSIC a set of real hyperspectral image experiments are performed where a commonly used spectral–spatial classification algorithm based on support vector machine (SVM) and edge-preserving filters (EPFs) is implemented for a comparative study and analysis. The results clearly demonstrate the potential of CS-HSIC in future research directions.

Demonstration of the Very Long Wavelength Infrared Type-II Superlattice InAs/InAsSb GaAs Immersed Photodetector Operating at Thermoelectric Cooling

In this letter, we report on the InAs/InAsSb type-II superlattice (T2SL) detector operating with 50% cut-off wavelength ( $\lambda _{\mathbf {c}})~\sim ~15~\mu \text{m}$ for temperatures ( T ) reached by three-stage thermoelectric (TE) cooling to minimize the detector’s volume to reach size, weight, and power (SWaP) conditions. The presented device reaches detectivity (D *) ~ 10 9 Jones ( $\lambda _{\mathrm {c}}\sim ~15~\mu \text{m}$ ). These results are the first reported on single pixel T2SL InAs/InAsSb photoconductor with $\lambda _{\mathrm {c}}\sim ~15~\mu \text{m}$ where GaAs immersion lens (IL) was implemented and integrated with three-stage Peltier TE cooler.

Secure Satellite Communication Digital IF CMOS $Q$ -Band Transmitter and $K$ -Band Receiver

This paper reports the first CMOS RF integrated chipset for secure commercial and military satellite communication enabling next-generation low size, weight, and power (SWaP) terminals. This chipset is a significant departure from current terminals relying on individually qualified IC components by taking advantage of advanced CMOS integration. The transmitter and receiver designs are digital IF architectures that rely on the higher sampling rate capability of CMOS, and precise digital filtering, quadrature frequency translation, and frequency hopping/de-hopping. The CMOS transmitter is a fully integrated system-on-chip (SoC) design, while the receiver consists of a co-designed RF and digital IF receiver. The Tx/Rx uses a 200-/300-MHz double data rate (DDR) interface driving/receiving a complex frequency translator with sub-hertz frequency hopping resolution via on-chip numerically controlled oscillators (NCO). The transmitter includes two 12-b return-to-zero (RZ) digital-to-analog converters (DACs) and quadrature modulator to form a single-sideband (SSB) upconverter achieving >30-dB spur rejection. An RF upconverter with an X2 multiplier drives a 24-dBm $Q$ -band CMOS stacked power amplifier (PA). The RF receiver implements a matched inverter amplifier (IA) followed by a complementary active balun that current drives a passive mixer with a trans-impedance active combiner. The digital IF receiver includes a high-linearity variable gain amplifier (VGA) that drives an 8 $\times $ time-interleaved 1.2-GS/s analog-to-digital converter (ADC) with dc offset and gain calibration with an embedded digital receiver. Both the transmitter and receiver use a 1.5-GHz IF signal. The combined CMOS chipset was demonstrated with a current military satcom modulation and protocol and achieves 5 $\times $ lower power consumption and size versus the current configuration.

A 183-GHz InP/CMOS-Hybrid Heterodyne-Spectrometer for Spaceborne Atmospheric Remote Sensing

A complete 183-GHz CMOS/Indium Phosphide (InP) hybrid heterodyne-spectrometer is realized for spaceborne atmospheric remote sensing applications. It captures spontaneous emission from thermally populated pure rotational states for investigating Earth/planetary atmosphere and interstellar media. Recent missions such as the heterodyne instrument for far-infrared, the microwave limb sounder, and the microwave instrument for Rosetta orbiter highlighted the wealth of scientific knowledge that can be attained by utilizing heterodyne-spectrometers. However, major challenges still remain in mission cost, instrument size, weight, and power (SWaP). Highly integrated CMOS circuits are designed to prototype a low-cost/SWaP spectrometer system and conduct challenging science missions. Within the prototype system, a 183-GHz receiver with a frequency synthesizer is designed in the 28-nm CMOS, and a back-end 6-GS/s 4096-point spectrometer processor is designed in the 65-nm CMOS. The receiver's center frequency is tunable from 180 to 200 GHz. An external InP low-noise amplifier is added at the front-end to provide the required receiver sensitivity. The demonstrated 28-nm CMOS receiver and 65-nm CMOS spectrometer consume 515 mW under 1.5/1.15-V and 1500 mW under 1 V supply, respectively. The complete system achieves 700 to 1000 K noise temperature within the interested bandwidth and RMS uncertainty improvement up to 10 s integration according to the Allan deviation measurements. The spectrometer's capability in detecting gas phase molecular compounds is verified with laboratory trials employing water (H2O) and methyl-cyanide (CH3CN).

Wideband adaptive microwave frequency identification using an integrated silicon photonic scanning filter

Photonic-assisted microwave frequency identification with distinct features, including wide frequency coverage and fast tunability, has been conceived as a key technique for applications such as cognitive radio and dynamic spectrum access. The implementations based on compact integrated photonic chips have exhibited distinct advantages in footprint miniaturization, light weight, and low power consumption, in stark contrast with discrete optical-fiber-based realization. However, reported chip-based instantaneous frequency measurements can only operate at a single-tone input, which stringently limits their practical applications that require wideband identification capability in modern RF and microwave applications. In this article, we demonstrate, for the first time, a wideband, adaptive microwave frequency identification solution based on a silicon photonic integrated chip, enabling the identification of different types of microwave signals from 1 to 30 GHz, including single-frequency, multiple-frequency, chirped-frequency, and frequency-hopping microwave signals, and even their combinations. The key component is a high Q-factor scanning filter based on a silicon microring resonator, which is used to implement frequency-to-time mapping. This demonstration opens the door to a monolithic silicon platform that makes possible a wideband, adaptive, and high-speed signal identification subsystem with a high resolution and a low size, weight, and power (SWaP) for mobile and avionic applications.

SpaceNaute® the HRG Based Inertial Reference System of Ariane 6 European space launcher

Modular, flexible and competitive, Ariane 6 is intended to offer the best space launch solution, by 2020, to commercial and institutional customers. Therefore it can’t anymore rely on legacy inertial reference. Advanced solutions were requested through an open tender conducted by ArianeGroup under European Space Agency (ESA) supervision. SpaceNaute®, the Safran solution based of HRG technology, was then selected against RLG and FOG based solutions proposed by the competitors. This paper describes the trade-off studies conducted to select the proper technology and describe the unique SWaP (Size, Weight and Power) breakthrough of SpaceNaute®, unveils key performance characteristics of the inertial sensors for SpaceNaute® and how HRG benefits are capitalized into the product

Design of highly directive lens-less photoconductive dipole antenna array with frequency selective surface for terahertz imaging applications

In this paper, a highly directive photoconductive dipole array antenna is presented for imaging system operating at terahertz (THz) frequencies. The array antenna is formed on a single photoconductive substrate to make it compact and suitable for THz imaging applications. The presented photoconductive dipole array antenna improves the gain as well as directivity and therefore, is useful to enhance the imaging capabilities to address the considerations such as limited depth-of-field (DoF) that is the distance over which an object is considered in focus and size-weight-and-power (SWaP) of THz source for imaging applications. These are important considerations for applications like stand-off imaging and surveillance of moving targets where the high angular resolution as well as extended DoF is the key for successful detection of hidden explosives and illicit drugs. In addition to this, a technique of using frequency selective surface with photoconductive array antenna is also presented to further enhance the directivity of the radiating structure to yield high image resolution. Moreover, by using this technique, the radiation energy has been confined to the desired frequency band rather than spreading over a wide spectrum range.

An Embodied Multi-Sensor Fusion Approach to Visual Motion Estimation Using Unsupervised Deep Networks.

Aimed at improving size, weight, and power (SWaP)-constrained robotic vision-aided state estimation, we describe our unsupervised, deep convolutional-deconvolutional sensor fusion network, Multi-Hypothesis DeepEfference (MHDE). MHDE learns to intelligently combine noisy heterogeneous sensor data to predict several probable hypotheses for the dense, pixel-level correspondence between a source image and an unseen target image. We show how our multi-hypothesis formulation provides increased robustness against dynamic, heteroscedastic sensor and motion noise by computing hypothesis image mappings and predictions at 76–357 Hz depending on the number of hypotheses being generated. MHDE fuses noisy, heterogeneous sensory inputs using two parallel, inter-connected architectural pathways and n (1–20 in this work) multi-hypothesis generating sub-pathways to produce n global correspondence estimates between a source and a target image. We evaluated MHDE on the KITTI Odometry dataset and benchmarked it against the vision-only DeepMatching and Deformable Spatial Pyramids algorithms and were able to demonstrate a significant runtime decrease and a performance increase compared to the next-best performing method.

Radar Technologies for Earth Remote Sensing From CubeSat Platforms

Space-based radar observations have transformed our understanding of Earth over the last several decades. Driven by increasingly complex science questions, space radar missions have grown ever more sophisticated with costs rising often to hundreds of millions of dollars. At the other end of the cost and complexity spectrum, CubeSats have emerged in recent years as a disruptive innovation in the satellite sector and are now considered a means to address targeted science questions in a rapid and affordable manner. CubeSats enable new kinds of constellation-based Earth science observations not previously affordable with traditional spacecraft. Constellations of low-cost sensors provide both global spatial and high temporal coverage. As such, CubeSats are not only viable platforms to address current Earth science goals, but they also open a new realm of possibilities for science advancement and unique applications. Radar instruments have often been regarded as unsuitable for small satellite platforms due to their traditionally large size, weight, and power (SWaP). Burgeoning missions such as Radar in a CubeSat (RainCube) and CubeSat Imaging Radar for Earth Science (CIRES), being developed by Jet Propulsion Laboratory and SRI International, respectively, and funded by NASA’s Earth Science Technology Office (ESTO), are slated to dispel this notion. The key to the simplification and miniaturization of the radar subsystems in a manner that still offers compelling science and applications is 1) component technological advancement; and 2) an integrated instrument architecture and mission design that exploits the capabilities offered by CubeSat platforms. This paper reviews the state-of-the-art and future developments of CubeSat radar missions for Earth remote sensing and the implications for NASA’s current and future Earth Science program. The key enabling technologies for radio frequency (RF), digital, and antennas are surveyed, as well as the evolution of the CubeSat avionics, in the aspects that mostly impact radar development, namely power, volume, and attitude control and knowledge and precision orbit determination (POD). We investigate various radar applications that could benefit from low-cost CubeSat platforms, such as altimetry, sounding, precipitation profiling, scatterometry, synthetic aperture radar (SAR), and interferometric SAR (InSAR). We also explore the science motivation and impact of future missions that are based on these technological advancements.

Algorithm on Converting a 2D Scanning LiDAR to 3D for use in Autonomous Indoor Navigation

Autonomous indoor navigation is synonymous with military centric autonomous navigation in GPS-denied environments. Unmanned aerial systems (UAS) are routinely connected to autonomous navigation. This combination of technology has many disparate uses such as in kids toys, photography, and military applications. For each of these areas a major concern is size, weight, and power (SWaP) in the product design. SWaP has a direct effect on the operations of an autonomous UAS such as on the flight time, the maneuverability, controllability, and the durability. This paper presents a basic algorithm describing one aspect of reducing SWaP on an autonomous quad-rotor UAS, by converting a 2D scanning LiDAR sensor to a 3D sensor, thus eliminating the need for additional sensors used to perform localization and mapping. Much that is described here is derived from the thesis work presented by Cooper. The majority of work was performed during a Master’s Thesis investigation by M. A. Cooper titled “Converting a 2D Scanning LiDAR to a 3D System for Use on Quad-Rotor UAVs in Autonomous Navigation.” The work presented here develops the generalized calibration procedure.

A software stack for next-generation automotive systems on many-core heterogeneous platforms

The next-generation of partially and fully autonomous cars will be powered by embedded many-core platforms. Technologies for Advanced Driver Assistance Systems (ADAS) need to process an unprecedented amount of data within tight power budgets, making those platform the ideal candidate architecture. Integrating tens-to-hundreds of computing elements that run at lower frequencies allows obtaining impressive performance capabilities at a reduced power consumption, that meets the size, weight and power (SWaP) budget of automotive systems. Unfortunately, the inherent architectural complexity of many-core platforms makes it almost impossible to derive real-time guarantees using “traditional” state-of-the-art techniques, ultimately preventing their adoption in real industrial settings. Having impressive average performances with no guaranteed bounds on the response times of the critical computing activities is of little if no use in safety-critical applications. Project Hercules will address this issue, and provide the required technological infrastructure to exploit the tremendous potential of embedded many-cores for the next generation of automotive systems. This work gives an overview of the integrated Hercules software framework, which allows achieving an order-of-magnitude of predictable performance on top of cutting-edge Commercial-Off-The-Shelf components (COTS). The proposed software stack will let both real-time and non real-time application coexist on next-generation, power-efficient embedded platforms, with preserved timing guarantees.

Obstacle Detection and Avoidance System Based on Monocular Camera and Size Expansion Algorithm for UAVs.

One of the most challenging problems in the domain of autonomous aerial vehicles is the designing of a robust real-time obstacle detection and avoidance system. This problem is complex, especially for the micro and small aerial vehicles, that is due to the Size, Weight and Power (SWaP) constraints. Therefore, using lightweight sensors (i.e., Digital camera) can be the best choice comparing with other sensors; such as laser or radar.For real-time applications, different works are based on stereo cameras in order to obtain a 3D model of the obstacles, or to estimate their depth. Instead, in this paper, a method that mimics the human behavior of detecting the collision state of the approaching obstacles using monocular camera is proposed. The key of the proposed algorithm is to analyze the size changes of the detected feature points, combined with the expansion ratios of the convex hull constructed around the detected feature points from consecutive frames. During the Aerial Vehicle (UAV) motion, the detection algorithm estimates the changes in the size of the area of the approaching obstacles. First, the method detects the feature points of the obstacles, then extracts the obstacles that have the probability of getting close toward the UAV. Secondly, by comparing the area ratio of the obstacle and the position of the UAV, the method decides if the detected obstacle may cause a collision. Finally, by estimating the obstacle 2D position in the image and combining with the tracked waypoints, the UAV performs the avoidance maneuver. The proposed algorithm was evaluated by performing real indoor and outdoor flights, and the obtained results show the accuracy of the proposed algorithm compared with other related works.

61‐1: Invited Paper: Light‐field Display Architecture and the Challenge of Synthetic Light‐field Radiance Image Rendering

The ability to render 3D data/scenes onto 2D displays have greatly enhanced the human ability to visualize complex scenes. However, when 3D information is projected in 2D, many of the natural depth cues are lost or are incorrect requiring a higher cognitive effort from the viewer to reconstruct the scene.A light‐field display projects perspective correct, full parallax 3D aerial imagery independent of the number of viewers or viewer positions. As such, light‐field displays enable collaboration and promote the analysis of complex information; however, the generation of the synthetic light‐field is computationally challenging with off‐the‐shelf GPUs. Light‐field projection fidelity aside, the high Size, Weight and Power (SWaP) cost of light‐field rendering ultimately limits the deployment of light‐field display systems. This is partly due to the issue that the modern GPUs and rendering APIs do not support multi‐view rendering natively.

Generation-After-Next Power Electronics: Ultrawide-bandgap devices, high-temperature packaging, and magnetic nanocomposite materials

A new generation of power electronic conversion systems is being enabled by wide-bandgap (WBG) devices. Applications in both the civilian and defense sectors are already beginning to benefit from the improved size, weight, and power (SWaP) now being demonstrated in power converters utilizing silicon carbide (SiC) and/or gallium nitride (GaN) switches, and numerous manufacturers are offering various types of switching devices fabricated from these two WBG semiconductors.

Large-aperture, wide-angle nonmechanical beam steering using polarization gratings

Liquid crystal polarization gratings (LCPGs) represent a relatively new technology capable of nonmechanically and efficiently steering light over a large field-of-regard in discrete steps. Due to their reliance on thin liquid crystal cells instead of mechanical moving parts, LCPG beam steering systems are attractive options for steering both active and passive optical sensors, especially in size, weight, and power (SWaP)-constrained platforms. This paper describes recent developments in large-aperture LCPG steering systems and summarizes the performance being achieved.

Ultra-High Density System-in-Package (SiP) for the Lowest Size Weight and Power (SWAP)

Abstract Fan out wafer level packages have emerged across the market in an effort to reduce size and weight of electronics used in portable and wearable applications in the commercial, industrial, and the hi-reliability products space. If it is not a stationary platform, weight and volume reduction are imperative. For the stationary platforms, size and power are most critical. Integration of multiple complex heterogeneous IC components can only be done if there are a sufficient number of interconnect layers. Additionally, multiple interconnects are needed for transmission line creation and shielding. This paper provides an introduction to Aurora Semiconductor's high density packaging technology i.e. iUHD (integrated Ultra High Density) and compares it with other alternative technologies. The Aurora iUHD technology is a 2.5D/3D FOWLCSP including embedded components, TSV, multi-layer top and bottom interconnects.

(Invited) Advanced Photonic Circuits Using III-V Semiconductors

Advances in photonic integrated circuits (PICs) have enabled increased system performance and new photonic system capabilities. Integration leads to reductions in SWaP (size, weight and power) and packaging costs, while increasing reliability and mechanical robustness when compared to discrete components. The unique characteristics of compound semiconductors enable monolithically integrated PICs with efficient integrated light sources, amplifiers and high performance modulators and detectors. Additionally, specialized discrete devices can be heterogeneously integrated with other photonic circuits to form more complex circuits. Sandia has developed a fundamental capability in InP-based PICs that enables the monolithic integration of a diverse set of lasers, modulators (both phase-based and absorption-based), photodetectors, amplifiers (both high-gain and high-saturation power varieties) and routing waveguides, in addition to electrical passive components such as resistors, capacitors, and transmission lines.The foundation of the capability is quantum-well-intermixing which enables the realization of multiple bandedges to be formed across the wafer with very low optical reflections (<1 dB) at the interfaces [1], coupled with simple blanket MOCVD regrowths This InP-based PIC platform allows for high performance components including >40 Gbps EAMs (electroabsorption modulators) and photodetectors [2], <1 GHz passband optical filters and wavelength-tunable lasers with >40 dB side mode suppression ratio on a single monolithic chip.This variety of devices enables the creation of unique, highly-functional PICs for a variety of applications. In addition, this PIC technology can also be combined with photonic technologies, including Si photonics, using heterogeneous integration to reduce costs and expand the application space. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Adaptive Digital Beamformer Autocalibration Using an Injected Noise Source

This paper presents a wideband closed-loop relative adaptive calibration method for digital beamformers in phased array applications. Using an internally distributed and injected additive white Gaussian noise source, we equalized the channels relative to a selected channel before beamforming. This relative injection method has a size, weight, and power (SWaP) advantage compared with an absolute method where a copy of the illumination waveform is used as the reference signal. Measured data from an existing 22-phase-center elemental digital beamformer array were used to evaluate the relative method against existing absolute methods. The channel response was extracted and the bit error rate was evaluated using a simulation test bench. A parametric conceptual design was also performed to evaluate the relative SWaP between the relative and absolute methods. The results show that the relative method is 17.6 times smaller, uses 1.3 times less power, and is 2.4 times lower in cost than the absolute method. The results also show that the relative calibration method can be as effective as an absolute method, given that the injected waveform has a higher signal-to-noise ratio than the ambient scene.

Size, weight, and power reduction regimes in achromatic gradient-index singlets.

By analyzing the limitations that achromatic gradient-index (GRIN) lens solutions in the radial and axial extremes place on lens thickness and surface curvature, a radial-axial hybrid GRIN theory is developed in order to overcome these restrictions and expose a larger solution space. With the achromatic hybrid GRIN theory, the trade-offs between thickness, curvature, and GRIN type can be directly studied in the context of size, weight, and power (SWaP) reduction. Finally, the achromatic solution space of a silicon-germanium-based material system is explored, and several designs are verified with ray tracing.

멀티코어 기반 파티셔닝 운영체제를 이용한 분산 복구 블록 설계 기법 및 응용

최근 항공기, 자동차와 같은 시스템들은 크기, 무게, 전력 등의 문제로 기존 연합형(Federated) 구조에서 모듈형(Modular) 구조로 개발되는 추세이며, 단일 하드웨어에 파티션 개념을 적용하여 다수의 논리적 노드들을 운용할 수 있는 파티션 운영체제도 등장하고 있다. 분산 복구 블록은 실시간 시스템에 적용 가능한 소프트웨어 결함 허용 기법으로 다수의 물리적 노드들을 동기화 시켜 동작시킴으로써 실시간 절체가 가능하도록 하는 설계 기법이다. 분산 복구 블록은 노드들 간의 실시간 동기화를 필요로 하기 때문에 단일 코어 기반의 파티션 구조에는 적합하지 않으며, 적용을 위해서는 멀티코어를 기반으로 하고 또한 AMP(Asymmetric Multi-Processing) 방식을 이용한 파티션 구조에 적용되어야 한다. 본 논문에서는 멀티코어 기반 supervised-AMP 가상화 방식의 파티션 운영체제를 이용한 분산 복구 블록 설계 기법을 제안한다. 또한 제안된 설계 기법의 유용성을 보이기 위하여 항공기용 비행제어시스템 시뮬레이션을 이용한 사례 연구를 보인다. Recently, embedded systems such as aircraft and automobilie, are developed as modular architecture instead of federated architecture because of SWaP(Size, Weight and Power) issues. In addition, partition operating system that support multiple logical node based on partition concept were recently appeared. Distributed recovery block is fault tolerance design scheme that applicable to mission critical real-time system to support real-time take over via real-time synchronization between participated nodes. Because of real-time synchronization, single-core based computer is not suitable for partition based distributed recovery block design scheme. Multi-core and AMP(Asymmetric Multi-Processing) based partition architecture is required to apply distributed recovery block design scheme. In this paper, we proposed design scheme of distributed recovery block on the multi-core based supervised-AMP architecture partition operating system. This paper implements flight control simulator for avionics to check feasibility of our design scheme.