Tech Briefs

Streams: A Hyper-Responsive Telemetry Interaction Tool on the Web

A new search database provides a hyper-responsive interface that allows operators to rapidly search for only the datapoints of interest.JPL Operations Engineers (Operators) need to interact with their telemetry to assess the health of and successfully operate a spacecraft or rover. Operators must analyze the immediate data for health and understand the current state of these complex systems, but they also must be able to evaluate the long-term engineering data to identify trends and potential pitfalls that develop over time. Whether starting with long-term trends or short-term data, operators have large amounts of data and need a tool so that their expertise is spent analyzing the data and trends, rather than working to tease these trends from outdated toolsets not equipped to handle large data sets. Existing tools pre-compute either long-term trends or short-term plots, but further ad-hoc analysis is prohibitively difficult, can take many hours per query, and queries necessitate either special access or that the operator be on a specific network to access data and to correlate it to models.

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

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Auto-Coding Flight Software Hybrid Controllers Synthesized from Formal Specifications

The technique of synthesizing state-machine-based hybrid controller flight software (FSW) from formal specifications is demonstrated utilizing two simple controller examples (i.e. a simple thermostat and a simple autonomous vehicle). Formal requirements for these controllers are specified using linear temporal logic (LTL) expressions, expressions describing the system dynamics, and numerical bounds on the control inputs and disturbances (or constraints). A new interface between the Temporal Logic Planning (TuLiP) toolbox — a hybrid controller synthesis software — and the JPL Statechart Autocoder (SCA) — a tool for mapping UML Statecharts to implementation code — was developed. The interface is still under development, but has reached sufficient maturity for demonstration. Results from preliminary prototype demonstrations encourage further collaboration between JPL and Caltech to develop a new capability for synthesizing hybrid controllers to be implemented within JPL Flight Software.

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

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Active Learning System for iPTF Candidate Classification

The Intermediate Palomar Transient Factory (iPTF) is a visible-spectrum astronomy survey aimed at detecting “transient” events such as supernovae. Every night, a telescope at the Palomar observatory collects images of various regions of the sky and compares them to a set of reference images taken on previous nights. The image comparison is done via a subtraction process. The reference images are subtracted from the new nightly images, and any remaining light sources are flagged as candidate transient events.

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

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Cobra: an Extendable Tool for Interactive Code Analysis

Source code analysis typically requires the use of expensive and difficult-to-configure tools that support only a predefined set of standard checks. In some cases, it is possible to add customized checks, but doing so can be laborious and requires a deep understanding of each tool’s internal data structures, which means that it is rarely done.

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

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Low-Power-Consumption, Single-Mode Quantum Cascade Lasers Fabricated Without Epitaxial Regrowth

These low-power lasers can be used for spectroscopy instruments in health and safety monitoring, and industrial process monitoring.Quantum cascade (QC) lasers employ intersubband electronic transitions in semiconductor quantum well structures to generate emission at specific engineered wavelengths. QC devices have been particularly successful as mid-infrared emitters in the 4- to 12-μm wavelength range, a spectral regime that is difficult to access with interband diode lasers. As cascade devices, QC lasers can also be designed with many gain stages, which, combined with optimized doping and optical design, has enabled the development of lasers with remarkably high continuous output power (in excess of 1 W). One of the most important applications of mid-infrared QC lasers is quantitative gas detection using absorption spectroscopy, where a single-frequency laser is used to interrogate specific absorption lines of a target compound. While high output power is essential in certain applications, many in situ absorption spectrometers require only milliwatt-level output to effectively measure low levels of compounds of interest with strong absorption lines in the mid-infrared regime.

Posted in: Briefs, Manufacturing & Prototyping

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Common Workflow Service: A Standards-Based Process Management System

As mission operations grow in scale and complexity, there is a prevailing need for automating operational processes to increase efficiency, mitigate risks, and reduce operational costs. The need for automating operational processes has produced a few disparate automation systems within the Advanced Multi Mission Operations System (AMMOS). Without a common solution for process management and automation, each AMMOS subsystem that requires a workflow capability will need to develop its own expertise in the workflow domain as independent systems are developed. This can lead to many incompatible implementations that functionally do similar things. The Common Workflow Service (CWS) attempts to address this issue to avoid independent ad hoc workflow implementations.

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

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Optimum Strategies for Selecting Descent Flight-Path Angles

Efficient and safe arrival operations under challenging traffic conditions are a key objective for air transportation modernization efforts taking place throughout the world. However, trajectory predictability issues often prevent Air Traffic Control (ATC) from allowing continuous descent approaches in congested airspace. An arrival procedure with a specific descent profile, such as a fixed-flight-path angle, provides high trajectory predictability for air-traffic management. Accordingly, it can enable ATC to increase the use of continuous descent approaches, thereby increasing the throughput of arrival operations and reducing fuel burn and other direct operating costs in the process. Moreover, such a procedure is already supported by current avionics in almost all small (regional, business, and light) jets and a fraction of large jets, including Boeing and Airbus.

Posted in: Briefs, Aeronautics, Aerospace

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