This PDF file contains the front matter associated with SPIE Proceedings Volume 8739, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

The Space Ultra Compact Hyperspectral Imager is a long wave infrared hyperspectral imager being built at the University of Hawaii. The sensor will be the primary payload on the HiakaSat small satellite scheduled for launch on the Office of Responsive Space ORS-4 mission, and planned for a 6 month primary mission which is extendable up to two years of operation on orbit. SUCHI is based on a variable-gap Fabry-Perot interferometer employed as a Fourier transform spectrometer and uses an uncooled 320x256 microbolometer array to collect the images. The sensor is low volume (16” x 4” x 5") and low mass (<9kg), to conform to the volume, mass, and power requirements of the small satellite. The commercial microbolometer camera and vacuum-sensitive electronics are contained within a sealed vessel pressurized to 1 atm. The sensor will collect spectral radiance data in the long wave infrared region (8-14 microns) and demonstrate the potential of this instrument for advancing the geological sciences (e.g. mapping of major rock-forming minerals) as well as for volcanic hazard assessment (mapping volcanic ash, quantification of volcanic sulfur dioxide pollution and lava flow cooling rates). The sensor is scheduled for delivery to the satellite in Spring 2013, with launch scheduled for Fall 2013.

We have developed a mission concept that uses 3-unit cubesats to perform new measurements of lunar magnetic fields, less than 100 meters above the Moon’s surface. The mission calls for sending the cubesats on impact trajectories to strongly magnetic regions on the surface, and transmitting measurements in real-time to a nearby spacecraft, or directly to the Earth, up until milliseconds before impact. The cubesats and their instruments are partly based on the NSF-funded CINEMA cubesat now in Earth orbit. Two methods of reaching the Moon as a secondary payload are discussed: 1) After launching into geostationary transfer orbit with a communication satellite, a small mother-ship travels into lunar orbit and releases the cubesats on impact trajectories, and 2) The cubesats travel to the Moon using their own propulsion after release into geosynchronous orbit. This latter version would also enable other near-Earth missions, such as constellations for studying magnetospheric processes, and observations of close-approaching asteroids.

Recent work, specifically the Lawrence Livermore National Laboratory (LLNL) Eyeglass and the DARPA MOIRE programs, have evaluated lightweight, easily packaged and deployed, diffractive/refractive membrane transmissive lenses as entrance apertures for large space and airborne telescopes. This presentation describes a new, innovative approach to the theory of diffractive and refractive effects in lenses used as telescope entrance apertures and the fabrication of the necessary large membrane optics. Analyses are presented to indicate how a broadband, highly transmissive diffractive / refractive membrane lens can be developed and fabricated, and potential applications in defense and astronomy are briefly discussed.

Characterization activities related to near-Earth asteroids (NEAs) provide several societal benefits. This work can serve as a precursor to a human exploration mission, it can facilitate the assessment of targets for resource extraction, and it can serve as preparation for intervention against the threat posed by an Earth impactor (EI). One objective of ongoing work at the University of North Dakota is to develop the capabilities required for NEA characterization. A CubeSatclass spacecraft will serve to demonstrate and test these required technologies on-orbit. This 1U CubeSat, which is compliant with NASA ELaNA CubeSat Launch Initiative requirements, will be comprised of standard subsystems (excluding propulsion) and a payload consisting of a visible light camera, a limited radio science package and a GPS receiver. The craft will also feature extensive onboard computing capabilities to allow it to process data to perform mosaicking, super-resolution and rudimentary image feature identification and analysis. This paper focuses on the onboard computing subsystem of this spacecraft which consists of a standard flight computer based on the AMTEL AT91SAM9G20 chipset and a supplemental processing unit based on several GumStix computeron- module (COM) units. The key design requirement: having an always-on primary processing unit and supplemental capabilities (including a digital signal processor) that can be powered on for use only when required and how the current design meets these requirements is reviewed. A detailed review of the spacecraft’s design and mission operations plan is presented. The numerous trades required to allow the requisite payload and onboard processing hardware to fit within the size and weight limitations posed by the 1U CubeSat form factor are discussed. Finally, the paper concludes with a review of the functionality provided by the spacecraft and the future capabilities that this functionality will facilitate.

The Hawaii Space Flight Laboratory (HSFL) at the University of Hawaii at Manoa is developing the capabilities to design, build, and operate constellations of small satellites than can be tailored to efficiently execute a variety of remote sensing missions. With the Operationally Responsive Space (ORS) Office, HSFL is developing the Super Strypi launch vehicle that on its initial mission in 2013 will launch the HSFL 55-kg HawaiiSat-1 into a near polar orbit, providing the first deployment of these technologies. This satellite will be carrying a miniature hyperspectral thermal imager developed by the Hawaii Institute of Geophysics and Planetology (HIGP). HSFL has also developed a method to efficiently deploy a constellation of small satellites using a minimal number of launch vehicles. Under a three-year NASA grant, HSFL is developing a Comprehensive Open-architecture Space Mission Operations System (COSMOS) to support these types of missions. COSMOS is being designed as a System of Systems (SoS) software integrator, tying together existing elements from different technological domains. This system should be easily adaptable to new architectures and easily scalable. It will be provided as Open Source to qualified users, so will be adoptable by even universities with very restricted budgets. In this paper we present the use of COSMOS as a System of Systems integrator for satellite constellations of up to 100 satellites and numerous ground stations and/or contact nodes, including a fully automated “lights out” satellite contact capability.

This paper designs a ground motion compensation servo system based on two-dimensional pointing mirror. The servo system is mainly composed of digital control unit, analog driving unit and driving motor. Besides, the control algorithm and strategy of driving motor would be given, and based on the control strategy, a closed-loop controller which consists of current loop, velocity loop and position loop is designed and simulated. Especially, the speed loop adopts pseudo differential feed-forward (PDFF) controller to avoid extensive overshoot. Finally, the experiment results show that the designed servo system has fast response and small overshoot.

Satellites have limited awareness of nearby objects that might pose a collision hazard. Small, relatively inexpensive onboard optical local area sensors have been proposed as a means of providing additional awareness. However, such sensors often have limited performance. Proposed are methods to increase the Local Area Awareness provided by such sensors by means of classical and novel image processing techniques. The local area of the sensor platform is defined, for our purposes, as a sphere of radius 500 km surrounding the sensor platform, or observing satellite. This analysis utilizes image differencing-based techniques, in the development of a detection algorithm and proposes a novel objectvelocity classifier. This classifier may provide a means of rapidly distinguishing local area objects that pose a possible collision hazard when an orbital two-line element set is not available. Derivation of a novel classifier is based on the speed of the projected object moving across the focal plane array of the detector. This technique relies on the assumption that detection from the sensor platform allows for tracking of the object over all times the object is within the local area of the sensor platform. This alternative to intensity-based, signalto- noise ratio detection methods is performed by exploiting the stellar background as a reference from a space-based observing satellite. Results presented in this paper further demonstrate the ability of the proposed classifier to provide a means of rapidly distinguishing objects that pose a possible hazard within the local area of the sensor platform. These preliminary results act to substantiate this claim and therefore lay out a pathway for relevant and meaningful future work in the area of Local Area Awareness for satellites.

Large satellites and exquisite planetary missions are generally self-contained. They have, onboard, all of the computational, communications and other capabilities required to perform their designated functions. Because of this, the satellite or spacecraft carries hardware that may be utilized only a fraction of the time; however, the full cost of development and launch are still bone by the program. Small satellites do not have this luxury. Due to mass and volume constraints, they cannot afford to carry numerous pieces of barely utilized equipment or large antennas. This paper proposes a cloud-computing model for exposing satellite services in an orbital environment. Under this approach, each satellite with available capabilities broadcasts a service description for each service that it can provide (e.g., general computing capacity, DSP capabilities, specialized sensing capabilities, transmission capabilities, etc.) and its orbital elements. Consumer spacecraft retain a cache of service providers and select one utilizing decision making heuristics (e.g., suitability of performance, opportunity to transmit instructions and receive results – based on the orbits of the two craft). The two craft negotiate service provisioning (e.g., when the service can be available and for how long) based on the operating rules prioritizing use of (and allowing access to) the service on the service provider craft, based on the credentials of the consumer. Service description, negotiation and sample service performance protocols are presented. The required components of each consumer or provider spacecraft are reviewed. These include fully autonomous control capabilities (for provider craft), a lightweight orbit determination routine (to determine when consumer and provider craft can see each other and, possibly, pointing requirements for craft with directional antennas) and an authentication and resource utilization priority-based access decision making subsystem (for provider craft). Two prospective uses for the proposed system are presented: Earth-orbiting applications and planetary science applications. A mission scenario is presented for both uses to illustrate system functionality and operation. The performance of the proposed system is compared to traditional self-contained spacecraft performance, both in terms of task performance (e.g., how well / quickly / etc. was a given task performed) and task performance as a function of cost. The integration of the proposed service provider model is compared to other control architectures for satellites including traditional scripted control, top-down multi-tier autonomy and bottom-up multi-tier autonomy.

PICARD is a spacecraft dedicated to the simultaneous measurement of the absolute total and spectral solar irradiance, the diameter, the solar shape, and to probing the Sun’s interior by the helioseismology method. The mission has two scientific objectives, which are the study of the origin of the solar variability, and the study of the relations between the Sun and the Earth’s climate. The spacecraft was successfully launched, on June 15, 2010 on a DNEPR-1 launcher. PICARD spacecraft uses the MYRIADE family platform, developed by CNES to use as much as possible common equipment units. This platform was designed for a total mass of about 130 kg at launch. This paper focuses on the design and testing of the TCS (Thermal Control System) and in-orbit performance of the payload, which mainly consists in two absolute radiometers measuring the total solar irradiance, a photometer measuring the spectral solar irradiance, a bolometer, and an imaging telescope to determine the solar diameter and asphericity. Thermal control of the payload is fundamental. The telescope of the PICARD mission is the most critical instrument. To provide a stable measurement of the solar diameter over three years duration of mission, telescope mechanical stability has to be excellent intrinsically, and thermally controlled. Current and future space telescope missions require ever-more dimensionally stable structures. The main scientific performance related difficulty was to ensure the thermal stability of the instruments. Space is a harsh environment for optics with many physical interactions leading to potentially severe degradation of optical performance. Thermal control surfaces, and payload optics are exposed to space environmental effects including contamination, atomic oxygen, ultraviolet radiation, and vacuum temperature cycling. Environmental effects on the performance of the payload will be discussed. Telescopes are placed on spacecraft to avoid the effects of the Earth atmosphere on astronomical observations (turbulence, extinction, ...). Atmospheric effects, however, may subsist when spacecraft are launched into low orbits, with mean altitudes of the order of 735 km.

This paper focuses on recent progress in designing FallconSAT-7, a 33U CubeSat solar telescope designed to image the Sun from low Earth orbit. The telescope system includes a deployable structure that supports a membrane photon sieve under tension as well as secondary optics. To satisfy mission requirements to demonstrate diffraction limited imaging capability of this collapsible, f/2 diffractive primary we have completed studying a number off effects on membrane material that can affect system imaging quality.

Shortly after the Earth observations with the VIIRS instrument launched onboard the Suomi NPP spacecraft have begun, it was observed that responsivity of some of the instrument’s spectral bands decreases with time faster than expected. It was determined that the VIIRS telescope mirror contamination with tungsten oxide is the root cause of the degradation, and that the rate of the degradation is controlled by exposure of the mirrors to ultraviolet radiation. We have monitored progress of the degradation using measurements of light reflected from the onboard calibrator’s solar diffuser and taking into account seasonal changes of the solar illumination of the diffuser. The measurements were then used to develop an empirical model of the degradation dynamics and predict future rate of the responsivity changes during the seven-year lifetime of the Suomi NPP mission.

We present a newly designed thermoelectric detector chip of high detectivity for the space mission BepiColombo to Mercury. The sensor is part of the MERTIS radiometer, which enables radiometric measurements in the spectral range from 7-40 micron to study the thermo-physical properties of the planet's surface material. In collaboration with the DLR Institute of Planetary Research, the Institute of Photonic Technology has developed a sensor array with a specific detectivity D* of 1.3 x 10⁹ Jones in vacuum environment and 2 x 15 individual readable channels. In addition, it has an optical slit in the middle, which serves as the entrance slit of a spectrometer downstream. The sensor area is coated with an absorbing layer, in this case silver black having an absorption coefficient of nearly 100 percent in a wavelength range from 0.4 up to 20 micron. To minimize the thermal cross talk between the individual pixels, each pixel is separated by a 50 micron slit in the self-supporting silicon nitride membrane. For good mechanical stability of the pixels, the pixel membrane is tensioned by 10 micron bridges like braces. The sensor is electrically contacted with a star-flex PCB by direct wire bonding and both are mounted on milled aluminum housing. At the Institute of Photonic Technology (IPHT), high detectivity radiation sensors are developed and based on the thermoelectric principle. The thermoelectric materials used are the highly effective combination of n-bismuth(87%)- antimony(13%) / p-antimony. The sensors are designed, in the main, as miniaturized multi-junction thermocouples and made by state of the art thin film technologies allowing for achievable and reproducible detectivities D* in the range of 10⁸ up to 2 x 10⁹ Jones.

We present new photonic-true-time-delay (PTTD) devices, which are a key component for phased array antenna (PAA) and phased array radar (PAR) systems. These new devices, which are highly manufacturable, provide the previously unattainable combination of large time delay tunability and low insertion loss, in a form factor that enables integration of many channels in a compact package with very modest power consumption. The low size, weight, and power are especially advantageous for satellite deployment. These devices are enabled by: i) “Optical Path Reflectors” or OPRs that compresses a >20 foot change in optical path length, i.e., a >20 nsec tuning of delay, into a very compact package (only centimeters), and ii) electro-optic angle actuators that can be used to voltage tune or voltage select the optical time delay. We have designed and built OPRs that demonstrated: large time delay tunability (<30 nsecs), high RF bandwidth (>40 GHz and likely much higher), high resolution (<200 psec), and low and constant insertion loss (< 1 dB and varying by < 0.5 dB). We also completed a full design and manufacturing run of improved EO angle actuators that met the PTTD scanner requirements. Finally, a complete optical model of these integrated devices will be presented, specifically; the design for a multi-channel (400 channels) PTTD device will be discussed. The applicability and/or risks for space deployment will be discussed.

In this paper we present new electro-optic beam steering technology and propose to combine it with optical telecommunication technology, thereby enabling low cost, compact, and rugged free space optical (FSO) communication modules for small-sat applications. Small satellite applications, particularly those characterized as “micro-sats” are often highly constrained by their ability to provide high bandwidth science data to the ground. This will often limit the relevance of even highly capable payloads due to the lack of data availability. FSO modules with unprecedented cost and size, weight, and power (SWaP) advantages will enable multi-access FSO networks to spread across previously inaccessible platforms. An example system would fit within a few cubic inch volume, require less than 1 watt of power and be able to provide ground station tracking (including orbital motion over wide angles and jitter correction) with a 50 to 100 Mbps downlink and no moving parts. This is possible, for the first time, because of emergent and unprecedented electro-optic (EO) laser scanners which will replace expensive, heavy, and power-consuming gimbal mechanisms. In this paper we will describe the design, construction, and performance of these new scanners. Specific examples to be discussed include an all electro-optic beamsteer with a 60 degree by 40 degree field of view. We will also present designs for a cube-sat to ground flight demonstration. This development would provide a significant enhancement in capabilities for future NASA and other Government and industry space projects.

As the demand for multiple radio frequency carrier bands continues to grow in space communication systems, the design of a cost-effective compact optical transmitter that is capable of transmitting selective multiple RF bands is of great interest, particularly for NASA Space Communications Network Programs. This paper presents experimental results that demonstrate the feasibility of a concept based on an optical wavelength division multiplexing (WDM) technique that enables multiple microwave bands with different modulation formats and bandwidths to be combined and transmitted all in one unit, resulting in many benefits to space communication systems including reduced size, weight and complexity with corresponding savings in cost. Experimental results will be presented including the individual received RF signal power spectra for the L, C, X, Ku, Ka, and Q frequency bands, and measurements of the phase noise associated with each RF frequency. Also to be presented is a swept RF frequency power spectrum showing simultaneous multiple RF frequency bands transmission. The RF frequency bands in this experiment are among those most commonly used in NASA space environment communications.

Improving orbital accuracy of space debris is one of the major prerequisite to performing reliable collision prediction in low earth orbit. The objective is to avoid false alarms and useless maneuvers for operational satellites. This paper shows how laser ranging on debris can improve the accuracy of orbit determination. In March 2012 a joint OCA-Astrium team had the first laser echoes from space debris using the MéO (Métrologie Optique) telescope of the Observatoire de la Côte d’Azur (OCA), upgraded with a nanosecond pulsed laser. The experiment was conducted in full compliance with the procedures dictated by the French Civil Aviation Authorities. To perform laser ranging measurement on space debris, the laser link budget needed to be improved. Related technical developments were supported by implementation of a 2J pulsed laser purchased by ASTRIUM and an adapted photo detection. To achieve acquisition of the target from low accuracy orbital data such as Two Lines Elements, a 2.3-degree field of view telescope was coupled to the original MéO telescope 3-arcmin narrow field of view. The wide field of view telescope aimed at pointing, adjusting and acquiring images of the space debris for astrometry measurement. The achieved set-up allowed performing laser ranging and angular measurements in parallel, on several rocket stages from past launches. After a brief description of the set-up, development issues and campaigns, the paper discusses added-value of laser ranging measurement when combined to angular measurement for accurate orbit determination. Comparison between different sets of experimental results as well as simulation results is given.

Observations of satellites in geosynchronous orbit (GEO) are routinely performed by optical sensors at night when the phase angle—the angle between the satellite’s lines of sight to earth and to sun—is less than about 85 degrees. Daytime optical observations of satellites in the GEO belt will be performed at larger phase angles. In afternoon and morning hours, small phase angles are available, but at mid-day the phase angle is constrained to be greater than a minimum value that depends upon the latitude of the sensor and time of year. On Maui at summer solstice, for example, the minimum phase angle is 110 degrees at mid-day for observations of the GEO belt. In order to predict their visibility during the daytime, observations of GEO satellites were conducted at night with a small-aperture telescope at the large phase angles available soon after dusk and before dawn. Analysis of the satellite images reveals a flattening in the light curve for phase angles greater than 100 degrees, and the data provide an empirical model of the expected satellite signal at all phase angles.

Anomaly detection has been considered as an important technique for detecting critical events in a wide range of data rich applications where a majority of the data is inconsequential and/or uninteresting. We study the detection of anomalous behaviors among space objects using the theory of conformal prediction for distribution-independent on-line learning to provide collision alerts with a desirable confidence level. We exploit the fact that conformal predictors provide valid forecasted sets at specified confidence levels under the relatively weak assumption that the normal training data, together with the normal testing data, are generated from the same distribution. If the actual observation is not included in the conformal prediction set, it is classified as anomalous at the corresponding significance level. Interpreting the significance level as an upper bound of the probability that a normal observation is mistakenly classified as anomalous, we can conveniently adjust the sensitivity to anomalies while controlling the false alarm rate without having to find the application specific threshold. The proposed conformal prediction method was evaluated for a space surveillance application using the open source North American Aerospace Defense Command (NORAD) catalog data. The validity of the prediction sets is justified by the empirical error rate that matches the significance level. In addition, experiments with simulated anomalous data indicate that anomaly detection sensitivity with conformal prediction is superior to that of the existing methods in declaring potential collision events.

The need for a global collaborating space situational awareness (SSA) network, including radars, optical and other sensors for communication and surveillance, has become a top priority for most countries who own or operate man-made space-crafts. Such a SSA system requires vast storage, powerful computing capacity and the ability to serve hundreds of thousands of users to access the same database. These requirements make traditional distributed networking system insufficient. Cloud computing, which features scalable and elastic storage and computing services, has been recognized as an ideal candidate that can meet the challenges of SSA systems' requirements. In this paper, we propose a Cloud-based information fusion system for SSA and examine a prototype that serves space tracking algorithms. We discuss the benefits of using Cloud Computing as an alternative for data processing and storage and explore details of Cloud implementation for a representative SSA system environment.

In this work, a Quality of Service (QoS)-aware routing (QAR) algorithm is developed for Low-Earth Orbit (LEO) polar constellations. LEO polar orbits are the only type of satellite constellations where inter-plane inter-satellite links (ISLs) are implemented in real world. The QAR algorithm exploits features of the topology of the LEO satellite constellation, which makes it more efficient than general shortest path routing algorithms such as Dijkstra’s or extended Bellman-Ford algorithms. Traffic density, priority, and error QoS requirements on communication delays can be easily incorporated into the QAR algorithm through satellite distances. The QAR algorithm also supports efficient load balancing in the satellite network by utilizing the multiple paths from the source satellite to the destination satellite, and effectively lowers the rate of network congestion. The QAR algorithm supports a novel robust routing scheme in LEO polar constellation, which is able to significantly reduce the impact of inter-satellite link (ISL) congestions on QoS in terms of communication delay and jitter.

Ubiquitous wireless networking requires efficient dynamic spectrum access (DSA) among heterogeneous users with diverse transmission types and bandwidth demands. To meet user-specific quality-of-service (QoS) requirements, the power and spectrum allocated to each user should lie inside a power/spectral-shape bounded region in order to be meaningful for the intended application. Most existing DSA methods aim at enhancing the total system utility. As such, spectrum wastage may arise when the system-wide optimal allocation falls outside individual users’ desired regions for QoS provisioning. In this work, novel QoS-aware DSA algorithms are developed for both non-cooperative power allocation (QoSNCPA) and cooperative (QoSCPA) users in cognitive radio (CR) networks. The algorithms maximize the “useful utilities” to the users, and minimize the power consumption and mutual interference within the CR network. Simulations results of the QoSNCPA and QoSCPA for single and multiple channel cases demonstrate the effectiveness of the algorithms for DSA.

For worldwide, a satellite communication network is an integral component of the global networking infrastructure. In this paper, we focus on developing effective routing techniques that consider both user preferences and network dynamic conditions. In particular, we develop a weighted-based route selection scheme for the core satellite communication network. Unlike the shortest path routing scheme, our scheme chooses the route from multiple matched entries based on the assigned weights that reflect the dynamic condition of networks. We also discuss how to derive the optimal weights for route assignment. To further meet user’s preference, we implement the multiple path routing scheme to achieve the high rate of data transmission and the preemption based routing scheme to guarantee the data transmission for high priority users. Through extensive simulation studies, our data validates the effectiveness of our proposed routing schemes.

Networking technologies are exponentially increasing to meet worldwide communication requirements. The rapid growth of network technologies and perversity of communications pose serious security issues. In this paper, we aim to developing an integrated network defense system with situation awareness capabilities to present the useful information for human analysts. In particular, we implement a prototypical system that includes both the distributed passive and active network sensors and traffic visualization features, such as 1D, 2D and 3D based network traffic displays. To effectively detect attacks, we also implement algorithms to transform real-world data of IP addresses into images and study the pattern of attacks and use both the discrete wavelet transform (DWT) based scheme and the statistical based scheme to detect attacks. Through an extensive simulation study, our data validate the effectiveness of our implemented defense system.

Debugging Wireless Sensor Network (WSN) applications deployed on actual sensor nodes is difficult, since debuggers normally require a wired (e.g. USB) interface. In this paper we propose a mechanism for WSN application debugging that is based on remote access, through the wireless interface, and that uses the native environment in which the application was developed (i.e. it acts as a source-level debugger). The approach, called RSD-WSN, is based on creating continuous behavioral snapshots of a remotely located sensor node by binding it with a virtual node. Hence by using RSD-WSN, users can debug a WSN application node that is running remotely. This framework allows a programmer to develop an application using high level abstractions (finite state machine) and then automatically generate code for target platforms. The complied generated code could be then directly loaded on sensor nodes and the framework provides interfaces by which an application developer can bind execution sequences of a remote sensor node with a virtual simulated node, so that the developer can monitor node behavior and refine the application in case of unexpected behaviors.

In this paper, a high-degree cubature information filter (CIF) is proposed for multiple sensor estimation. Astatistical linear error propagation method incorporates the high-degree cubature integration rule into the extended information filtering (EIF) framework such that more accurate estimation can be achieved than the extended information filter as well as the unscented information filter (UIF). In addition, the high-degree CIF maintains close performance to the Gauss-Hermite Quadrature information filter (GHQIF) but uses significantly fewer quadrature points. As a result, the curse of dimensionality problem existing in the tensor product based GHQIF can be greatly alleviated. Besides the improved estimation accuracy and computational efficiency, the high-degree CIF also exhibits the desirable robustness under unknown noise statistics. The proposed CIF is compared with other information filters (e.g., EIF, UIF, GHQIF) via a target tracking problem and demonstrates the best performance.

Over the last decade it has been established that medium- to long-range weather patterns are significantly affected by stratospheric events, and it is well known that the severe storms are critically dependent on the winds aloft. However, existing observations of the dynamical atmosphere above the cloud tops are sparse and irregular, and remote measurements of upper atmospheric winds have historically proved challenging. Current numerical models must rely on data from widely separated land-based instruments and satellite observations with modest precision and coverage. Even less plentiful are observations of the neutral atmosphere above 100 km, despite the high potential impact of space weather on global navigational and electrical systems. We present here a new instrument concept, the Doppler Wind and Temperature Sounder (DWTS) that will enable global daily measurements of winds and temperature from 15 to 250 km with fine vertical and horizontal sampling. The measurement concept leverages the high spectral resolution inherently available with gas-filter correlation radiometry. By exploiting the Doppler shifts resulting from a limbviewing low Earth orbit satellite, DWTS spectrally resolves large ensembles of atmospheric emission features. From this, we are able to extract horizontal wind vectors and kinetic temperature with unprecedented precision. Here we review the DWTS measurement concept, present simulation results, and conclude by describing a low-cost operational system that would quantify atmospheric dynamics from the lower stratosphere into the mid thermosphere for the first time.

A 16 element HgCdTe e-APD detector has been developed for lidar receivers that has significant improvements in sensitivity in the spectral range from < 1μm to 4 μm. A demonstration detector consisting of a 4x4 APD detector array, with 80 μm square elements, a custom CMOS readout integrated circuit (ROIC), a closed cycle cooler-Dewar, and support electronics has been designed, fabricated, and tested. The custom ROIC design provides > 6 MHz bandwidth with low noise and 21 selectable gains. Ninety-six arrays were fabricated with 69% of the arrays meeting the dark current spec in the center 4 pixels at 10 V bias where the APD gain was expected to be around 150. Measurements to 12 V on one array showed APD gains of 654 with a gain normalized dark currents of 1.2 fA to 3.2 fA. The lowest dark current array showed a maximum dark current of 6.2 pA at 10 V and 77 K. The 4.4 μm cutoff detector was characterized at an operating temperature of 77K with a 1.55 μm, 1μs wide, laser pulse. The photon conversion efficiency at unity gain was 91%. The mean measured APD gain at 77 K was 308 at 11V, the responsivity was 782 μV/pW, the average NEP was 1.04 fW/Hz^1/2. The bandwidth was 6.8 MHz, and the broadband NEP was 2.97 pW. This detector offers a wide spectral response, dynamic range, and substantially improved sensitivity and lifetime for integrated path differential absorption (IPDA) lidar measurements of atmospheric trace gases such as CO2 and CH4.

Previous astrophysical studies have explained the orbital dynamics of particles that acquire a high electrostatic charge. In low Earth orbit, the charge collected by a microscopic particle or an ultra-small, low-mass satellite interacts with the geomagnetic field to induce the Lorentz force which, in the ideal case, may be exploited as a form of propellantless propulsion. Efficient mechanisms for negative and positive electrostatic charging of a so-called attosatellite are proposed considering material, geometry, and emission interactions with the ionosphere’s neutral plasma with characteristic Debye length. A novel model-based plasma physics study was undertaken to optimize the positive charge mechanism quantified by the system charge-to-mass ratio. In the context of the practical system design considered, a positive charge-to-mass ratio on the order of 1.9x10^-9 C/kg is possible with maximum spacecraft potential equal to the sum of the kinetic energy of electrons from active field emission (+43V) and less than +5V from passive elements. The maximum positive potential is less than what is possible with negative electrostatic charging due to differences in thermal velocity and number density of electronic and ionic species. These insights are the foundation of a practical system design.

A method is proposed for extracting attitude data from streaked star images using traditional image processing methods. The process enables collection of both attitude and angular velocity estimates from streaking star images, where traditional star identification methods would produce poor results. Star streak endpoints are localized as "corner-like" portions of a streak. A vector cross-product based method is developed to produce a proper grouping in time for endpoints. Star identification and single point attitude determination methods can be applied to each set of endpoints, retrieving two sets of data from a single image. Monte Carlo results are presented, and the implications of the results are discussed. Multiple corner detection methods are considered and compared. Future work needed to mature the process is discussed. Results indicate an endpoint detection accuracy of less than a tenth of a pixel for a camera angle to the rotation axis of greater than 20 degrees and streak lengths up to 40% of the field of view.

Automatic vehicle license plate recognition (LPR) is important for intelligent traffic surveillance systems. This paper suggests a vehicle license plate algorithm, color component texture detection and template matching (CCTD-TM). CCTD-TM has advantages of ease of implementation and highly efficient in calculation. We suggest a novel algorithm of color component texture for license plate localization. This algorithm takes advantage of the feature of fixed color texture of plate base and character. The image preprocessing and character recognition by template matching parts are included in the LPR algorithm. The preliminary results demonstrate an average detection rate over 96.5% and an average recognition rate over 89.9% on hundreds of vehicle images tested in the experiments.

This paper presents a fuzzy based approach to segmenting color images in three steps. First, we discuss a fuzzy color extractor to extract fuzzy color components. Second, we present techniques for iteratively generating reference patterns (seeds) to extract color components. Finally, we use the region growing method to check connectivity of segmented subimages. Different from the existing color segmentation methods that provide a crisp segmentation of color images, the proposed approach herein generates a fuzzy color segmentation which classifies the same pixel into several fuzzy sets. As an example, we apply the proposed approach to segment the chemical plumes from images taken in undersea environments.

Atmospheric clouds are commonly encountered phenomena affecting visual tracking from air-borne or space-borne sensors. Generally clouds are difficult to detect and extract because they are complex in shape and interact with sunlight in a complex fashion. In this paper, we propose a clustering game theoretic image segmentation based approach to identify, extract, and patch clouds. In our framework, the first step is to decompose a given image containing clouds. The problem of image segmentation is considered as a “clustering game”. Within this context, the notion of a cluster is equivalent to a classical equilibrium concept from game theory, as the game equilibrium reflects both the internal and external (e.g., two-player) cluster conditions. To obtain the evolutionary stable strategies, we explore three evolutionary dynamics: fictitious play, replicator dynamics, and infection and immunization dynamics (InImDyn). Secondly, we use the boundary and shape features to refine the cloud segments. This step can lower the false alarm rate. In the third step, we remove the detected clouds and patch the empty spots by performing background recovery. We demonstrate our cloud detection framework on a video clip provides supportive results.

In this paper, we formulate the problem of infrared target tracking as a binary classification task and extend the online multiple instance learning tracker (MILTracker) for the task. Compared with many color or texture based tracking algorithms, the MILtracker highlights the difference between the target and the background or similar objects, and is thus suitable for infrared target tracking which undergoes serious textual information loss. To address the specific challenges in the infrared sequences, we extend the original MILtracker from two aspects. Firstly, an adaptive motion prediction procedure is integrated in to enhance the efficiency of the tracker. This step helps discriminate disturbing objects that are visual very similar to the target under tracking. Secondly, a spatial weight mask is introduced into the target representation to augment its robustness against similar background clutters, especially distracters. We apply the proposed approach on several challenging IR sequences. The experimental results clearly validate the effectiveness of our method with encouraging performances.