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Advanced P-Band Spaceborne Radar System

A new imaging approach can overcome the fundamental limitations of conventional radar systems. Goddard Space Flight Center, Greenbelt, Maryland Low-cost, flexible spaceborne radar architectures are needed to provide critical data for Earth and science applications. An instrument concept was developed for an advanced spaceborne radar system that can measure terrestrial biomass (woody mass per unit area), ecosystem structure (height and density), and extent on a global scale. The PNTB band polarimetric radar architecture employs advanced techniques to increase the science value of the measurements while achieving it at a lower cost. The spaceborne radar concept leverages the existing airborne L-band digital beamforming synthetic aperture radar (DBSAR) and the new P-band digital beamforming (DBF) polarimetric and interferometric EcoSAR (ESTO IIP) architectures that employ DBF and reconfigurable hardware to provide advanced radar capabilities not possible with conventional radar instruments.

Posted in: Physical Sciences, Briefs, TSP

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Global Fire Detection Constellation

Small satellites could monitor and process images to track fires from space. NASA’s Jet Propulsion Laboratory, Pasadena, California Wildfires that start in backcountry areas sometimes burn for hours before being detected and reported. Satellites offer a vantage point from which infrared sensors can detect fires. Individual satellites in low Earth orbit (LEO) offer infrequent overpasses, making the delay from ignition to detection unacceptably long. Geostationary satellites offer a platform from which to maintain a round-the-clock vigil, but lack geographic precision, and cannot detect a rather small fire within a large pixel definitively above noise.

Posted in: Physical Sciences, Briefs, TSP

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Compact Solid-State Entangled Photon Source

John H. Glenn Research Center, Cleveland, Ohio In the fields of quantum information, quantum optics, quantum cryptography, and quantum communications, there is a need to generate entangled photon pairs. The entangled photon pairs are described by an inseparable wave equation such that if a measurement is performed on one photon, its twin’s photon state is completely determined. The problem up to now is that these sources of entangled photons require large, expensive, and power-intensive Ar-ion lasers to generate light in the UV to pump a nonlinear crystal to produce spontaneous parametric down conversion (SPDC). The SPDC process generates a pair of photons (the signal and the idler) whose momentum and energy sum up to equal the initial pump photon.

Posted in: Physical Sciences, Briefs, TSP

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Interface Validation for Distributed Software Systems

Goddard Space Flight Center, Greenbelt, Maryland As a result of performing IV&V (Independent Verification and Validation) on Space Station software, a number of interface faults were found during integrated testing or actual software deployment. Faults found at this late phase of the software development lifecycle are very expensive to fix. Other research indicates that significant cost savings can be realized if these types of faults can be discovered at earlier software development lifecycle phases, such as specification or coding. A need was determined for processes, procedures, and tools that will reliably identify interface faults during these earlier software development lifecycle phases. The ability to perform interface validation during earlier phases will reduce costly fixes due to interface faults discovered during later software development phases.

Posted in: Information Sciences, Electronics & Computers, Briefs, TSP

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Simple, Scalable, Script-Based Science Processing Archive

The system provides data access control, data subscription, metadata publication, and data recovery. Goddard Space Flight Center, Greenbelt, Maryland Simple, Scalable, Script-based, Science Processing (S4P) Archive (S4PA) is a disk-based data-archiving system for remote sensing data. It is based on the data-driven framework of S4P. The system is used for new data transfer, data preprocessing, metadata generation, and data archival. The system provides services such as data access control, data subscription, metadata publication, and data recovery. The data is archived on readily available disk drives, with FTP (File Transfer Protocol) and HTTP (Hypertext Transfer Protocol) being primary modes of data access. S4PA includes a graphical user interface for monitoring and re-configuring the system operation, a tool for deploying the system, and various other tools that help manage the data ingest and archiving process, such as data replication, auxiliary file backup, database merge, storage of dataset README documents in CVS (Concurrent Versions System), an interface for machine search, deployment of S4PA instances from configuration stored in CVS, etc.

Posted in: Information Sciences, Electronics & Computers, Briefs, TSP

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A Model-Driven Science Data Product Registration Service

The Registry Service will provide functionality for tracking, auditing, locating, and maintaining artifacts within the system. NASA’s Jet Propulsion Laboratory, Pasadena, California The Planetary Data System (PDS) has undertaken an effort to overhaul the PDS data architecture (e.g., data model, data structures, data dictionary, etc.) and deploy a software system (online data services, distributed data catalog, etc.) that fully embraces the PDS federation as an integrated system while leveraging modern information technology. A core component of this new system is the Registry Service that will provide functionality for tracking, auditing, locating, and maintaining artifacts within the system. These artifacts can range from data files and label files, schemas, dictionary definitions for objects and elements, documents, services, etc.

Posted in: Information Sciences, Electronics & Computers, Briefs, TSP

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Design of Rate-Compatible Protograph LDPC Codes

This method can be applied in wireless cellular, satellite, and Internet communications. NASA’s Jet Propulsion Laboratory, Pasadena, California The most common way to generate a rate-compatible family of codes is puncturing. In this method, one starts with a low-rate mother code and then selectively discards some of the coded bits to arrive at higher-rate codes. This approach is simple, but is not free of problems. Specifically, the mother code is optimally designed for low rates, so higher-rate punctured codes have a wider gap to capacity, and the optimal low-rate code structure and puncturing patterns are designed separately, which is suboptimal. Even though it has been shown that puncturing can theoretically achieve the same gap to capacity as the mother code, in existing codes puncturing has in creased the gap significantly.

Posted in: Information Sciences, Electronics & Computers, Briefs

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