Information Technology & Software

Converting From DDOR SASF to APF

A computer program called “ddor_sasf2apf” converts delta-door (delta differential one-way range) request from an SASF (spacecraft activity sequence file) format to an APF (apgen plan file) format for use in the Mars Reconnaissance Orbiter (MRO) mission-planning-and- sequencing process. The APF is used as an input to “APGEN/AUTOGEN” in the MRO activity- planning and command-sequence-generating process to sequence the delta-door (DDOR) activity. The DDOR activity is a spacecraft tracking technique for determining spacecraft location.

Posted in: Briefs, Information Sciences, Communication protocols, Computer software and hardware, Surveillance, Spacecraft

Converting From CVF to AAF

A computer program called “dsn config converter” automates what had been a manual process for updating the multi-mission adaptation file (multi.aaf) used by a multiple- mission- command- sequence- generating process comprised of a combination of the AUTOGEN and APGEN programs mentioned in the immediately preceding article. The program converts the dsn_config.cvf file that provides DSN (Deep Space Network) antenna configuration code mappings from a context variable file (CVF) format used in another part of the command generation process to an APGEN activity file (AAF) format used by AUTOGEN and APGEN.

Posted in: Briefs, Information Sciences, Communication protocols, Computer software and hardware, Flight management systems, Automation

Documenting AUTOGEN and APGEN Model Files

A computer program called “autogen hypertext map generator” satisfies a need for documenting and assisting in visualization of, and navigation through, model files used in the AUTOGEN and APGEN software mentioned in the two immediately preceding articles. This program parses autogen script files, autogen model files, PERL scripts, and apgen activity-definition files and produces a hypertext map of the files to aid in the navigation of the model. This program also provides a facility for adding notes and descriptions, beyond what is in the source model represented by the hypertext map. Further, this program provides access to a summary of the model through variable, function, sub routine, activity and resource declarations as well as providing full access to the source model and source code. The use of the tool enables easy access to the declarations and the ability to traverse routines and calls while analyzing the model.

Posted in: Briefs, Information Sciences, Cartography, Computer software and hardware, Human machine interface (HMI)

Sequence History Update Tool

The Sequence History Update Tool performs Web-based sequence statistics archiving for Mars Reconnaissance Orbiter (MRO). Using a single UNIX command, the software takes advantage of sequencing conventions to automatically extract the needed statistics from multiple files. This information is then used to populate a PHP database, which is then seamlessly formatted into a dynamic Web page.

Posted in: Briefs, Information Sciences, Statistical analysis, Internet, Documentation, Spacecraft

MRO DKF Post-Processing Tool

This software tool saves time and reduces risk by automating two labor-intensive and error- prone post-processing steps required for every DKF [DSN (Deep Space Network) Keyword File] that MRO (Mars Reconnaissance Orbiter) produces, and is being extended to post-process the corresponding TSOE (Text Sequence Of Events) as well. The need for this post- processing step stems from limitations in the seq-gen modeling resulting in incorrect DKF generation that is then cleaned up in post-processing.

Posted in: Briefs, Information Sciences, Computer software and hardware, Telemetry, Performance upgrades, Reliability, Spacecraft

MRO Sequence Checking Tool

The MRO Sequence Checking Tool program, mro_check, automates significant portions of the MRO (Mars Reconnaissance Orbiter) sequence checking procedure. Though MRO has similar checks to the ODY’s (Mars Odyssey) Mega Check tool, the checks needed for MRO are unique to the MRO spacecraft.

Posted in: Briefs, Information Sciences, Computer software and hardware, Automation, Reliability, Spacecraft

Science Activity Planner for the MER Mission

The Maestro Science Activity Planner is a computer program that assists human users in planning operations of the Mars Explorer Rover (MER) mission and visualizing scientific data returned from the MER rovers. Relative to its predecessors, this program is more powerful and easier to use. This program is built on the Java Eclipse open-source platform around a Web-browser- based user-interface paradigm to provide an intuitive user interface to Mars rovers and landers.

Posted in: Briefs, Information Sciences, Computer software and hardware, Flight management systems, Human machine interface (HMI), Performance upgrades, Spacecraft

UAVSAR Flight-Planning System

A system of software partly automates planning of a flight of the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) — a polarimetric synthetic-aperture radar system aboard an unpiloted or minimally piloted airplane. The software constructs a flight plan that specifies not only the intended flight path but also the setup of the radar system at each point along the path.

Posted in: Briefs, Information Sciences, Computer software and hardware, Flight management systems, Radar, Unmanned aerial vehicles

Schema for Spacecraft-Command Dictionary

An Extensible Markup Language (XML) schema was developed as a means of defining and describing a structure for capturing spacecraft command-definition and tracking information in a single location in a form readable by both engineers and software used to generate software for flight and ground systems. A structure defined within this schema is then used as the basis for creating an XML file that contains command definitions. The schema is divided into three sections:

Posted in: Briefs, Information Sciences, Computer software and hardware, Terminology, Spacecraft

Self-Adjusting Hash Tables for Embedded Flight Applications

A common practice in computer science to associate a value with a key is to use a class of algorithms called a hash-table. These algorithms enable rapid storage and retrieval of values based upon a key. This approach assumes that many keys will need to be stored immediately. A new set of hash-table algorithms optimally uses system resources to ideally represent keys and values in memory such that the information can be stored and retrieved with a minimal amount of time and space. These hash-tables support the efficient addition of new entries. Also, for large data sets, the look-up time for large data-set searches is independent of the number of items stored, i.e., O(1), provided that the chance of collision is low.

Posted in: Briefs, TSP, Information Sciences, Embedded software

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