Special Coverage

Home

Autonomic Quiescence

An alternative method to self-destruct shuts down an agent or craft that is in danger or endangering a mission. Goddard Space Flight Center, Greenbelt, Maryland Biologically inspired autonomous and autonomic systems (AAS) are essentially about creating self-directed and self-managing systems based on metaphors such as that of the autonomic nervous system. Agent technologies have been identified as a key enabler for engineering autonomy and autonomicity in systems, both in terms of retrofitting into legacy systems and designing new systems. Handing over responsibility to the systems raises concerns for humans. This invention is a result of continued investigation into a strand of research on how to engineer self-protection mechanisms into the systems to assist in providing mechanisms to control the scope and consequences of using autonomy and autonomicity.

Posted in: Electronics & Computers, Briefs

Read More >>

Optimization of OT-MACH Filter Generation for Target Recognition

A substantial improvement in detection performance has been achieved. NASA’s Jet Propulsion Laboratory, Pasadena, California An automatic Optimum Trade-Off Maximum Average Correlation Height (OT-MACH) filter generator for use in a gray-scale optical correlator (GOC) has been developed for improved target detection. While the OT-MACH filter has been shown to be an optimal filter for target detection, actually solving for the optimum is too computationally intensive for multiple targets. Instead, an adaptive step gradient descent method was tested to iteratively optimize the three OT-MACH parameters a, b, and g. The feedback for the gradient descent method was a composite of the performance measures, correlation peak height, and peak to side-lobe ratio.

Posted in: Information Sciences, Briefs

Read More >>

A Decision Support Tool to Assess Upper-Level Winds for Space Launch

Faster, more reliable forecasts have been developed. An Excel-based graphical user interface (GUI) was developed for the 45th Weather Squadron (45 WS) Launch Weather Officers (LWOs), allowing them to assess numerical weather prediction model forecasts of upper-level winds and compare the forecasts to observations from Cape Canaveral Air Force Station meteorological soundings and the Kennedy Space Center 50-MHz Doppler Radar Wind Profiler in support of space launch operations at the Eastern Range. The GUI allows the LWOs to first initialize the models by comparing the 0-hour model forecasts to the observations, and then to display model forecasts in 3-hour intervals from the current time through 12 hours.

Posted in: Information Sciences, Electronics & Computers, Briefs

Read More >>

Change Detection in Orbital Images Using Relative Landmark Graphs

A method was developed for comparing the set of landmarks extracted from two images of the same location. NASA’s Jet Propulsion Laboratory, Pasadena, California Traditional methods for change detection involve the pixel-wise registration of two images and a subsequent differencing operation that highlights any changes at the individual pixel level. These methods have two limitations: (1) they are computationally expensive, and (2) they are extremely sensitive to misregistration and any changes in illumination.

Posted in: Information Sciences, Briefs

Read More >>

Heavy-Alkane Oxidation Kinetic-Mechanism Reduction

The new model is valid for n-heptane, iso-octane, n-decane, and n-dodecane. NASA’s Jet Propulsion Laboratory, Pasadena, California Oxidation chemical reactions of many practical fuels encompass thousands of species. When simulating complex turbulent reactive flows, it is impossible to account for the time and spatial evolution of all these species given current and foreseeable-future computer memory and time. This innovation reduces the number of necessary species to be tracked to only a few species, while still retaining faithfulness of the time and spatial evolution of the temperature and of the tracked species. The time evolution is currently the main focus.

Posted in: Information Sciences, Briefs

Read More >>

Covariance Analysis of Astrometric Alignment Estimation Architectures for Precision Dual-Spacecraft Formation Flying

A paper highlights analysis of proposed navigation systems and architectures for achieving precise dual-spacecraft astrometric alignment. The dynamics of dual-spacecraft relative motion, within a restricted n-body problem framework, are shown to reduce to a simple linear form for use in estimation filter design and error analysis for a deep space mission application, such as MASSIM (Milli-Arc-Second Structure Imager). This model is augmented with simplified measurement process models of relevant measurement types. These include inertial sensors, such as accelerometers and rate gyros, as well as optical alignment sensors, such as star and laser beacon trackers. A consider-state covariance analysis tool is developed from these process models and used to study the performance of proposed estimation architectures for the MASSIM application. This work develops a generic analysis methodology for evaluation of dual-spacecraft relative navigation systems and architectures for precise dual-spacecraft astrometric alignment.

Posted in: Physical Sciences, Briefs

Read More >>

Automated Purgatoid Identification

An algorithm was developed that automatically processes images captured by the HiRISE camera on the Mars Reconnaissance Orbiter to identify and locate the presence of purgatoids in monochrome images.

Posted in: Physical Sciences, Briefs

Read More >>