Direct Detection of Planets Orbiting Large Angular Diameter Stars: Sensitivity of an Internally Occulting Space-based Coronagraph

High-contrast imaging observations of large angular diameter stars enable complementary science questions to be addressed compared to the baseline goals of proposed missions like the Terrestrial Planet Finder-Coronagraph, New World's Observer, and others. Such targets, however, present a practical problem in that finite stellar size results in unwanted starlight reaching the detector, which degrades contrast. In this paper, we quantify the sensitivity, in terms of contrast, of an internally occulting, space-based coronagraph as a function of stellar angular diameter, from unresolved dwarfs to the largest evolved stars. Our calculations show that an assortment of band-limited image masks can accommodate a diverse set of observations to help maximize mission scientific return. We discuss two applications based on the results: the spectro-photometric study of planets already discovered with the radial velocity technique to orbit evolved stars, which we elucidate with the example of Pollux b, and the direct detection of planets orbiting our closest neighbor, α Centauri, whose primary component is on the main sequence but subtends an appreciable angle on the sky. It is recommended that similar trade studies be performed with other promising internal, external, and hybrid occulter designs for comparison, as there is relevance to a host of interesting topics in planetary science and related fields

Optical Splitting Trees for High-Precision Monocular Imaging

This paper introduces a framework to design optical splitting tree to perform computational photography tasks that require many sensors with a common optical axis. As the number of sensors increases, designing a good optical system is often difficult because the components have nonideal characteristics.The authors describe an optimization tool takes this into account and finds "good" designs as specified by several weighted coefficients. Assisted by this optimizer, they demonstrate high-dynamic range, focusing, matting, high-speed, and hybrid imaging implemented on a single, reconfigurable camera containing eight sensors.Engineering and Applied Science

Vision Sensors and Edge Detection

Vision Sensors and Edge Detection book reflects a selection of recent developments within the area of vision sensors and edge detection. There are two sections in this book. The first section presents vision sensors with applications to panoramic vision sensors, wireless vision sensors, and automated vision sensor inspection, and the second one shows image processing techniques, such as, image measurements, image transformations, filtering, and parallel computing

“Design, Development and Characterization of a Thermal Sensor Brick System for Modular Robotics

This thesis presents the work on thermal imaging sensor brick (TISB) system for modular robotics. The research demonstrates the design, development and characterization of the TISB system. The TISB system is based on the design philosophy of sensor bricks for modular robotics. In under vehicle surveillance for threat detection, which is a target application of this work we have demonstrated the advantages of the TISB system over purely vision-based systems. We have highlighted the advantages of the TISB system as an illumination invariant threat detection system for detecting hidden threat objects in the undercarriage of a car. We have compared the TISB system to the vision sensor brick system and the mirror on a stick. We have also illustrated the operational capability of the system on the SafeBot under vehicle robot to acquire and transmit the data wirelessly. The early designs of the TISB system, the evolution of the designs and the uniformity achieved while maintaining the modularity in building the different sensor bricks; the visual, the thermal and the range sensor brick is presented as part of this work. Each of these sensor brick systems designed and implemented at the Imaging Robotics and Intelligent Systems (IRIS) laboratory consist of four major blocks: Sensing and Image Acquisition Block, Pre-Processing and Fusion Block, Communication Block, and Power Block. The Sensing and Image Acquisition Block is to capture images or acquire data. The Pre-Processing and Fusion Block is to work on the acquired images or data. The Communication Block is for transferring data between the sensor brick and the remote host computer. The Power Block is to maintain power supply to the entire brick. The modular sensor bricks are self-sufficient plug and play systems. The SafeBot under vehicle robot designed and implemented at the IRIS laboratory has two tracked platforms one on each side with a payload bay area in the middle. Each of these tracked platforms is a mobility brick based on the same design philosophy as the modular sensor bricks. The robot can carry one brick at a time or even multiple bricks at the same time. The contributions of this thesis are: (1) designing and developing the hardware implementation of the TISB system, (2) designing and developing the software for the TISB system, and (3) characterizing the TISB system, where this characterization of the system is the major contribution of this thesis. The analysis of the thermal sensor brick system provides the user and future designers with sufficient information on parameters to be considered to make the right choice for future modifications, the kind of applications the TISB could handle and the load that the different blocks of the TISB system could manage. Under vehicle surveillance for threat detection, perimeter / area surveillance, scouting, and improvised explosive device (IED) detection using a car-mounted system are some of the applications that have been identified for this system

Exploration of a Polarized Surface Bidirectional Reflectance Model Using the Ground-Based Multiangle Spectropolarimetric Imager

Accurate characterization of surface reflection is essential for retrieval of aerosols using downward-looking remote sensors. In this paper, observations from the Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) are used to evaluate a surface polarized bidirectional reflectance distribution function (PBRDF) model. GroundMSPI is an eight-band spectropolarimetric camera mounted on a rotating gimbal to acquire pushbroom imagery of outdoor landscapes. The camera uses a very accurate photoelastic-modulator-based polarimetric imaging technique to acquire Stokes vector measurements in three of the instrument's bands (470, 660, and 865 nm). A description of the instrument is presented, and observations of selected targets within a scene acquired on 6 January 2010 are analyzed. Data collected during the course of the day as the Sun moved across the sky provided a range of illumination geometries that facilitated evaluation of the surface model, which is comprised of a volumetric reflection term represented by the modified Rahman-Pinty-Verstraete function plus a specular reflection term generated by a randomly oriented array of Fresnel-reflecting microfacets. While the model is fairly successful in predicting the polarized reflection from two grass targets in the scene, it does a poorer job for two manmade targets (a parking lot and a truck roof), possibly due to their greater degree of geometric organization. Several empirical adjustments to the model are explored and lead to improved fits to the data. For all targets, the data support the notion of spectral invariance in the angular shape of the unpolarized and polarized surface reflection. As noted by others, this behavior provides valuable constraints on the aerosol retrieval problem, and highlights the importance of multiangle observations.NASAJPLCenter for Space Researc

Advanced study of coastal zone oceanographic requirements for ERTS E and F

Earth Resources Technology Satellites E and F orbits and remote sensor instruments for coastal oceanographic data collectio

The NASA SBIR product catalog

The purpose of this catalog is to assist small business firms in making the community aware of products emerging from their efforts in the Small Business Innovation Research (SBIR) program. It contains descriptions of some products that have advanced into Phase 3 and others that are identified as prospective products. Both lists of products in this catalog are based on information supplied by NASA SBIR contractors in responding to an invitation to be represented in this document. Generally, all products suggested by the small firms were included in order to meet the goals of information exchange for SBIR results. Of the 444 SBIR contractors NASA queried, 137 provided information on 219 products. The catalog presents the product information in the technology areas listed in the table of contents. Within each area, the products are listed in alphabetical order by product name and are given identifying numbers. Also included is an alphabetical listing of the companies that have products described. This listing cross-references the product list and provides information on the business activity of each firm. In addition, there are three indexes: one a list of firms by states, one that lists the products according to NASA Centers that managed the SBIR projects, and one that lists the products by the relevant Technical Topics utilized in NASA's annual program solicitation under which each SBIR project was selected