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NASA NTRS2013

Common Web Mapping and Mobile Device Framework for Display of NASA Real-time Data

Scientists have strategic goals to deliver their unique datasets and research to both collaborative partners and more broadly to the public. These datasets can have a significant impact locally and globally as has been shown by the success of the NASA Short‐term Prediction Research and Transition (SPoRT) Center and SERVIR programs at Marshall Space Flight Center. Each of these respective organizations provides near real‐time data at the best resolution possible to address concerns of the operational weather forecasting community (SPoRT) and to support environmental monitoring and disaster assessment (SERVIR). However, one of the biggest struggles to delivering the data to these and other Earth science community partners is formatting the product to fit into an end user's Decision Support System (DSS). The problem of delivering the data to the end‐user's DSS can be a significant impediment to transitioning research to operational environments especially for disaster response where the deliver time is critical. The decision makers, in addition to the DSS, need seamless access to these same datasets from a web browser or a mobile phone for support when they are away from their DSS or for personnel out in the field. A framework has been developed for MSFC Earth Science program that can be used to easily enable seamless delivery of scientific data to end users in multiple formats. The first format is an open geospatial format, Web Mapping Service (WMS), which is easily integrated into most DSSs. The second format is a web browser display, which can be embedded within any MSFC Science web page with just a few lines of web page coding. The third format is accessible in the form of iOS and Android native mobile applications that could be downloaded from an "app store". The framework developed has reduced the level of effort needed to bring new and existing NASA datasets to each of these end user platforms and help extend the reach of science data.

Burks, Jason E.↗

NASA NTRS2013

Common Web Mapping and Mobile Device Framework for Display of NASA Real-time Data

Burks, Jason↗

NASA NTRS2011

Magnetospheric Multiscale (MMS) Mission Attitude Ground System Design

This paper describes the attitude ground system (AGS) design to be used for support of the Magnetospheric MultiScale (MMS) mission. The AGS exists as one component of the mission operations control center. It has responsibility for validating the onboard attitude and accelerometer bias estimates, calibrating the attitude sensors and the spacecraft inertia tensor, and generating a definitive attitude history for use by the science teams. NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland is responsible for developing the MMS spacecraft, for the overall management of the MMS mission, and for mission operations. MMS is scheduled for launch in 2014 for a planned two-year mission. The MMS mission consists of four identical spacecraft flying in a tetrahedral formation in an eccentric Earth orbit. The relatively tight formation, ranging from 10 to 400 km, will provide coordinated observations giving insight into small-scale magnetic field reconnection processes. By varying the size of the tetrahedron and the orbital semi-major axis and eccentricity, and making use of the changing solar phase, this geometry allows for the study of both bow shock and magnetotail plasma physics, including acceleration, reconnection, and turbulence. The mission divides into two phases for science; these phases will have orbit dimensions of l.2xl2 Earth radii in the first phase and l.2x25 Earth radii in the second in order to study the dayside magnetopause and the nightside magnetotail, respectively. The orbital periods are roughly one day and three days for the two mission phases. Each of the four MMS spacecraft will be spin stabilized at 3 revolutions per minute (rpm), with the spin axis oriented near the ecliptic north pole but tipped approximately 2.5 deg towards the Sun line. The main body of each spacecraft will be an eight-sided platform with diameter of 3.4 m and height of 1.2 m. Several booms are attached to this central core: two axial booms of 14.9 m length, two radial magnetometer booms of 5 m length, and four radial -wire booms of 60 m length. Attitude and orbit control will use a set of axial and radial thrusters. A four-head star tracker and a slit-type digital Sun sensor (DSS) provide input for attitude determination. In addition, an accelerometer will be· used for closed-loop orbit maneuver control. The primary AGS product will be a daily definitive attitude history. Due to power limitations; the star tracker and accelerometer data will not be available at all times. However, tracker data from at least 10 percent of each orbit and continuous DSS data will be provided. An extended Kalman filter (EKF) will be used to estimate the three-axis attitude (i.e., spin axis orientation and spin phase) and rotation rate for all times when the tracker data is valid. For other times, the attitude is generated by assuming a constant angular momentum vector in the inertial frame. The DSS sun pulse will provide a timing signal to maintain an accurate spin phase. There will be times when the Sun is occulted and DSS data is not available. If this occurs at the start or end of a definitive attitude product, then the spin phase will be extrapolated using the mean rate determined by the EKF.

Sedlak, Joseph E.↗

NASA NTRS1992

An OSI Architecture for the Deep Space Network

The flexibility and robustness of a monitor and control system are a direct result of the underlying inter-processor communications architecture. A new architecture for monitor & control at the Deep Space Network Communications Complexes has been developed based on the Open System Interconnection (OSI) standards. The suitability of OSI standards for DSN M&C has been proven in the laboratory. The laboratory success has resulted in choosing an OSI-based architecture for DSS-13 M&C. DSS-13 is the DSN experimental station and is not part of the "operational" DSN; it's role is to provide an environment to test new communications concepts can be tested and conduct unique science experiments. Therefore, DSS-13 must be robust enough to support operational activities, while also being flexible enough to enable experimentation. This paper describes the M&C architecture developed for DSS-13 and the results from system and operational testing.

OSI↗

NASA NTRSDate not supplied

Use of the SPoRT Stoplight Product to Support NWS Decision Support Services

The National Weather Service Forecast Offices (NWSFOs) use many weather tools and observational datasets to provide support for critical decision-making by core partners such as public safety officials, emergency managers, and first responders. These core partners who need weather decision support services (DSS) for outdoor events require up-to-the-minute weather information to ensure the safety and protection of attendees and workers. Storms and lightning, potentially deadly, pose a significant threat during outdoor events and are among the weather phenomena frequently cited as a DSS requirement. According to the National Lightning Safety Council, from 2014 up to August 2024, lightning resulted in 222 fatalities in the U.S. For outdoor events with hundreds to thousands of attendees, having the right tools to detect and monitor lightning activity is of utmost importance to protect lives. Common guidelines for lightning safety include moving inside a substantial structure at the first sight of threatening skies or the first sound of thunder, and waiting 30 minutes after the last lightning flash or thunder before returning outside. Using this guidance as a framework, scientists at the NASA Short-term Prediction Research and Transition (SPoRT) center have developed the Geostationary Lightning Mapper (GLM) Stoplight tool. This experimental tool uses the GLM Flash Extent Density imagery to display the location and recency of lightning flashes. To simplify interpretation, these lightning pixels are color-coded in 10-minute bins, ranging from red (lightning detected 0 to 10 minutes ago) to yellow (10 to 20 minutes ago) to green (20 to 30 minutes ago). The Stoplight tool also allows users to place markers at the location of outdoor events with range rings around the location to help in assessing the location and relative age of lightning flashes near and upstream of the event. The goal is to help NWS forecasters provide core partners with the necessary information to make the best decisions possible. While the Stoplight tool is experimental, forecasters at NWSFO Raleigh, NC, have periodically used the Stoplight guidance to evaluate its utility within NWS DSS. This presentation will discuss how the Stoplight tool was successfully used for DSS for four outdoor events in central NC in 2023 and 2024. Future improvements to this tool, including the addition of AI applications and the merging of ground-based lightning data with GLM data, will be reviewed.

Gail Hartfield↗

NASA NTRS1972

Tracking and data system support for the Mariner Mars 1971 mission. Prelaunch phase through first trajectory correction maneuver, volume 1

The DSN command system provided the capability to enter commands in a computer at the deep space stations for transmission to the spacecraft. The high-rate telemetry system operated at 16,200 bits/sec. This system will permit return to DSS 14 of full-resolution television pictures from the spacecraft tape recorder, plus the other science experiment data, during the two playback periods of each Goldstone pass planned for each corresponding orbit. Other features included 4800 bits/sec modem high-speed data lines from all deep space stations to Space Flight Operations Facility (SFOF) and the Goddard Space Flight Center, as well as 50,000 bits/sec wideband data lines from DSS 14 to the SFOF, thus providing the capability for data flow of two 16,200 bits/sec high-rate telemetry data streams in real time. The TDS performed prelaunch training and testing and provided support for the Mariner Mars 1971/Mission Operations System training and testing. The facilities of the ETR, DSS 71, and stations of the MSFN provided flight support coverage at launch and during the near-earth phase. The DSSs 12, 14, 41, and 51 of the DSN provided the deep space phase support from 30 May 1971 through 4 June 1971.

Laeser, R. P.↗

NASA NTRS1976

DSN research and technology support

The activities of the Venus Station (DSS 13) and the Microwave Test Facility (MTF) during the period April 19 through June 13, 1976, are discussed and progress noted. Continuing reliability testing and computer program refinement of the remote controlled, unattended automated pulsar observing station is noted, along with routine observations of 17 pulsars. Radar observations of a geostationary satellite are reported, along with the routine automatic testing of the stability of the DSS 13 maser-receiving system. Additional testing of thermal characteristics of semiflexible coaxial cables is reported, along with phase stabilization measurements thereon. Routine support of the planetary radio astronomy experiment, with 43.25 hours of observations of Jupiter and various radio calibration sources, is reported, along with 18.75 hours of differential VLBI observations in conjunction with Australia, DSS 43. Modifications of the clock synchronization winterization system are reported, along with a discussion of the activities of the DSN High-Power Transmitter Maintenance Facility.

Jackson, E. B.↗

NASA NTRS1977

DSN research and technology support

The ongoing activities at the Venus Station (DSS 13) and the Microwave Test Facility (MTF) discussed include: (1) equipment implementation for unattended operation at DSS 13; (2) salvaging of a 20-kW klystron, at a cost savings of several thousand dollars by the DSN High Power Transmitter Facility; (3) extensive tracking activities with the 26-m antenna including DSN Platform Parameters, Multistation Planetary Radar, Helios II Spectrum Broadening Analysis, VLBI Validation, Planetary Radio Astronomy, and Pulsar Rotation Constancy, for a total time of 219-1/4 observing hours; (4) clock synchronization transmissions from the DSS 13 master clock to the overseas 64-m antenna complexes and special implementation activities in support of PV-78; and (5) implementation of a hydrogen maser frequency standard and the pathfinder installation of a utility control system (UCS) and significant station modification and maintenance.

Jackson, E. B.↗

NASA NTRS1977

The 26-meter S-X Conversion Project

The 26-meter S-X conversion project provides for the conversion of an existing 26-meter S-band subnet to a 34-meter S- and X-band subnet. The subnet chosen for conversion consists of the following stations: DSS 12 near Barstow, DSS 44 in Australia, and DSS 62 in Spain. The main subsystems effected by this project are the antenna mechanical, antenna microwave, and receiver-exciter. In addition to these, there are many project-related electronic equipments that have been added to the existing station equipment. The major subsystems are essentially through the design stage with the antenna mechanical subsystem completed through detail design with procurement in process.

Lobb, V. B.↗

NASA NTRS1977

A high-speed computer link for moderate distances and noisy environments

To satisfy the need for a fully duplex high-speed computer data link for the antenna automation project at DSS 13, a very simple and inexpensive scheme was employed. The link requires two coaxial cables over which is sent a unipolar digital frequency modulated signal in which a logical 1 has twice the frequency of a logical 0. Optical isolators and filters reduce ground loop effects and increase noise immunity. Tests conducted in various environments and over different cable lengths at JPL, DSS 14 and DSS 13 have indicated that the link is highly effective.

Sievers, M. W.↗

NASA NTRS1980

Voyager mission support

Special events participated in by the Deep Space Stations (DSS) for the period of February through April 1980 are presented. The status of the DSS is reviewed for the same period, including system performance tests and operational verification tests. A list of software accepted for operation at the DSS is given.

Fanelli, N.↗

NASA NTRS1982

The 26-meter antenna s-x conversion project

Programmatic and management aspects of converting an existing 26-meter S-band subnet to a 34-meter S- and X-band subnet of the Deep Space Network are described. The stations involved were DSS 12 near Barstow, DSS 44 in Australia, and DSS 62 in Spain. The main subsystems affected by the conversion were the antenna mechanical, antenna microwave, and receiver-exciter. Antenna mechanial modifications and electronic additions and changes are described. The design and analysis of critical areas are considered and antenna performance is discussed.

Source record↗

NASA NTRS1983

Techniques for Analysis of DSN 64-meter Antenna Azimuth Bearing Film Height Records

The DSN 64-m antennas use oil pad azimuth thrust bearings. Instrumentation on the bearing pads measures the height of the oil film between the pad and the bearing runner. Techniques to analyze the film height record are developed and discussed. The analysis techniques present the unwieldy data in a compact form for assessment of bearing condition. The techniques are illustrated by analysis of a small sample of film height records from each of the three 64-m antennas. The results show the general condition of the bearings of DSS 43 and DSS 63 as good to excellent, and a DSS 14 as marginal.

Stevens, R.↗

NASA NTRS1986

X-band uplink feedcone capabilities, components, and layout

Two new X-(7.2 GHz up, 8.4 GHz down) and S-band (2.1 to 2.3 Ghz) common aperture (XSC) feedcones are being added to the DSS 45 and DSS 65 34-Meter Efficiency Antennas. These new feedcones are modifications of the existing SXC feedcone design incorporating a new high power (20-kW) X-band transmitter. The modified Antenna Microwave Subsystem design also incorporates two additional X-band low noise amplifiers and greater phase stability performance to meet both the increased stability requirements for Galileo gravity wave experiments and requirements for spacecraft navigation near the Sun. A third XSC will be constructed for DSS 15 later.

Marlin, H.↗

NASA NTRS1986

PPM/NAR 8.4-GHz noise temperature statistics for DSN 64-meter antennas, 1982-1984

From August 1982 through November 1984, X-band downlink (8.4-GHz) system noise temperature measurements were made on the DSN 64-m antennas during tracking periods. Statistics of these noise temperature values are needed by the DSN and by spacecraft mission planners to assess antenna, receiving, and telemetry system needs, present performance, and future performance. These measurements were made using the DSN Mark III precision power monitor noise-adding radiometers located at each station. It is found that for DSS 43 and DSS 63, at the 90% cumulative distribution level, equivalent zenith noise temperature values fall between those presented in the earlier (1977) and present (1983) versions of DSN/Flight Project design documents. Noise temperatures measured for DSS 14 (Goldstone) are higher than those given in existing design documents and this disagreement will be investigated as a diagnostic of possible PPM or receiving system performance problems.

Slobin, S. D.↗

NASA NTRS1987

Microwave component time delays for the 70-meter antennas

The X-band feed assemblies in the 64 meter antennas were redesigned to accommodate the upgrading to 70 meters and the associated surface reshaping. To maintain time delay data logs, new calculations were made of the microwave component delays for the XRO Mod IV X-band (8.4 to 8.45 GHz) feed assembly that was installed at DSS-63, and will soon be implemented at DSS-43 and DSS-14.

Hartop, R.↗

NASA NTRS1989

DSN 70-meter antenna X- and S-band calibration. Part 1: Gain measurements

Aperture efficiency measurements made during 1988 on the three 70-m stations (DSS-14, DSS-43, and DSS-63) at X-band (8420 MHz) and S-band (2295 MHz) have been analyzed and reduced to yield best estimates of antenna gain versus elevation. The analysis has been carried out by fitting the gain data to a theoretical expression based on the Ruze formula. Newly derived flux density and source-size correction factors for the natural radio calibration sources used in the measurements have been used in the reduction of the data. Peak gains measured at the three stations were 74.18 (plus or minus 0.10) dBi at X-band, and 63.34 (plus or minus 0.03) dBi at S-band, with corresponding peak aperture efficiencies of 0.687 (plus or minus 0.015) and 0.762 (plus or minus 0.006), respectively. The values quoted assume no atmosphere is present, and the estimated absolute accuracy of the gain measurements is approximately plus or minus 0.2 dB at X-band and plus or minus 0.1 dB at S-band (1-sigma values).

Richter, P. H.↗

NASA NTRS1991

A carrier-arraying demonstration at Goldstone for receiving Pioneer 11 signals

A carrier arraying technique was demonstrated at Goldstone. The Block III receivers of two 34-m antennas, Deep Space Station 12 and 15, were arrayed together to receive S band (2.3 GHz) signals from the Pioneer 11 spacecraft. Carrier phases in the two receivers were synchronized by the analog phase lock loops, and carrier signals were added at an intermediate frequency to enhance tracking performance. The receiver at DSS 15, which has been unable to lock up and track the Pioneer 11 signal by itself due to a wider tracking loop bandwidth and a higher system temperature, was now able to track the carrier and produce usable baseband signals. The receiver at DSS 12 achieved a reduction of the rms phase error, increasing the telemetry symbol SNR by an average of 0.35 dB. The baseband signals from both antennas were then synchronized and combined using the existing Baseband Assembly, thereby achieving a total symbol SNR increase of 2.5 + or - 0.7 dB relative to DSS 12 alone. A more comprehensive model is presented to permit evaluation of both thermal and phase noise effects. The analysis agrees well with observed data.

Pham, T. T.↗