Ace-s/c acceptance checkout equipment.
Carry-on, facility and ground station equipment, remote-control acceptance checkout equipment and monitoring system
CHECKOUT EQUIPMENT↗
SEARCH · Engineering Papers
Results for “GROUND STATION”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Study of modulation techniques for multiple access satellite communications
Multiple access communication utilizing small ground stations for satellite communication modulation - multiplexing techniques
SATELLITE COMMUNICATION↗
Simplifying operations with an uplink/downlink integration toolkit
The Operations Engineering Lab (OEL) at JPL has developed a simple, generic toolkit to integrate the uplink/downlink processes, (often called closing the loop), in JPL's Multimission Ground Data System. This toolkit provides capabilities for integrating telemetry verification points with predicted spacecraft commands and ground events in the Mission Sequence Of Events (SOE) document. In the JPL ground data system, the uplink processing functions and the downlink processing functions are separate subsystems that are not well integrated because of the nature of planetary missions with large one-way light times for spacecraft-to-ground communication. Our new closed-loop monitoring tool allows an analyst or mission controller to view and save uplink commands and ground events with their corresponding downlinked telemetry values regardless of the delay in downlink telemetry and without requiring real-time intervention by the user. An SOE document is a time-ordered list of all the planned ground and spacecraft events, including all commands, sequence loads, ground events, significant mission activities, spacecraft status, and resource allocations. The SOE document is generated by expansion and integration of spacecraft sequence files, ground station allocations, navigation files, and other ground event files. This SOE generation process has been automated within the OEL and includes a graphical, object-oriented SOE editor and real-time viewing tool running under X/Motif. The SOE toolkit was used as the framework for the integrated implementation. The SOE is used by flight engineers to coordinate their operations tasks, serving as a predict data set in ground operations and mission control. The closed-loop SOE toolkit allows simple, automated integration of predicted uplink events with correlated telemetry points in a single SOE document for on-screen viewing and archiving. It automatically interfaces with existing real-time or non real-time sources of information, to display actual values from the telemetry data stream. This toolkit was designed to greatly simplify the user's ability to access and view telemetry data, and also provide a means to view this data in the context of the commands and ground events that are used to interpret it. A closed-loop system can prove especially useful in small missions with limited resources requiring automated monitoring tools. This paper will discuss the toolkit implementation, including design trade-offs and future plans for enhancing the automated capabilities.
Murphy, Susan C.↗
Large antenna apertures and arrays for deep space communications
Effect of frequency on communications capability, single antennas and arrays, and economic balance between ground station and spacecraft development
FREQUENCY CONTROL↗
Protocol Sensing Across Multiple Space Missions
In this work, we present sensing performance using an architecture for a reconfigurable protocol chip for spacebased applications. Toward utilizing the IP packet architecture, utilizing data link layer framing structures for multiplexed data on a channel are the targeted application considered for demonstration purposes. Specifically, we examine three common framing standards and present the sensing performance of these standards and their relative de-correlation metrics. Some analysis is performed to investigate the impact of lossy links and on the number of packets required to perform a decision with some probability. Finally, we present results on a demonstration platform that integrated reconfigurable sensing technology into the Ground Station Interface Device (GRID) for End-to-End IP demonstrations in space.
Ground Station Interface Device (GRID)↗
Description and results of tests performed at Fucino Earth Station with Relay I
Communications and tracking facilities of Fucino ground station in Italy, and experiments conducted with Relay I satellite
COMMUNICATION SYSTEM↗
Variations of the earth's gravitational field from camera tracking of satellites
Simultaneous determinations of tesseral harmonic coefficients of gravitational field, ground station coordinates, and orbital elements by satellite photographic tracking
TESSERAL HARMONICS↗
Biomedical engineering units display systems for checkout and flight of gemini spacecraft.
Gemini ground station pulse code modulation display systems which make biochemical and environmental parameters available in binary codes
PULSE MODULATION↗
DETERMINATION OF CONDITIONS FOR MULTIPLE USE OF FREQUENCY ALLOCATIONS FOR SATELLITE COMMUNICATIONS AND GROUND SERVICES
Frequency assignment for communication satellite and ground station - tropospheric scatter, terrain shielding, and microwave transmission
COMMUNICATIONS SATELLITE↗
Reconfigurable Protocol Sensing in an End-to-End Demonstration
In this work, we present sensing performance using an architecture for a reconfigurable protocol chip for spacebased applications. Toward utilizing the IP packet architecture, utilizing data link layer framing structures for multiplexed data on a channel are the targeted application considered for demonstration purposes. Specifically, we examine three common framing standards and present the sensing performance of these standards and their relative de-correlation metrics. Some analysis is performed to investigate the impact of lossy links. Finally, we present results on a demonstration platform that integrated reconfigurable sensing technology into the Ground Station Interface Device (GRID) for End-to-End IP demonstrations in space.
space based applications↗
The telstar satellite system
This paper describes the Telstar system and discusses the over-all system design. System considerations, the orbit selection and frequency allocation considerations are covered. A general description of the Telstar satellite and Andover, Maine, ground station provides background for companion articles in this series. Finally, the transmission performance is given with some discussion of system parameters.
TELSTAR SATELLITE↗
Ground Calibration of an Orbiting Spacecraft Transmitter
The SeaWinds Calibration Ground Station (CGS) is a novel Ku-band receiving station that supports the June 1999-launched JPL/NASA SeaWinds scatterometer radar which measures the near-surface wind speeds over 90% of the ice-free oceans.
QuickSCAT SeaWinds Calibration Ground Station CGS↗
Non-Gimbaled Antenna Pointing
The small satellite community has been interested in accessing fixed ground stations for means of space-to-ground transmissions, although a problem arises from the limited global coverage. There is a growing interest for using the Space Network (SN) or Tracking and Data Relay Satellites (TDRS) as the primary support for communications because of the coverage it provides. This thesis will address the potential for satellite access of the Space Network with a non-gimbaled antenna configuration and low-power, coded transmission. The non-gimbaled antenna and the TDRS satellites, TDRS-East, TDRS-West, and TDRS-Zone of Exclusion, were configured in an orbital analysis software package called Satellite Tool Kit to emulate the three-dimensional position of the satellites. The access potential, which is the average number of contacts per day and the average time per contact, were obtained through simulations run over a 30-day period to gain all the possible orientations. The orbital altitude was varied from 600 km through 1200 km with the results being a function of orbital inclination angles varying from 20 deg through 100 deg and pointing half-angles of I0 deg through 40 deg. To compare the validity of the simulations, Jet Propulsion Laboratory granted the use of the TOPEX satellite. The TOPEX satellite was configured to emulate a spin-stabilized antenna with its communications antenna stowed in the zenith-pointing direction. This mimicked the antenna pointing spin-stabilized satellite in the simulations. To make valid comparisons, the TOPEX orbital parameters were entered into Satellite Tool Kit and simulated over five test times provided by Jet Propulsion Laboratory.
Vigil, Jeannine S.↗
Orbit Determination Error Analysis Results for the Triana Sun-Earth L2 Libration Point Mission
Using the NASA Goddard Space Flight Center's Orbit Determination Error Analysis System (ODEAS), orbit determination error analysis results are presented for all phases of the Triana Sun-Earth L1 libration point mission and for the science data collection phase of a future Sun-Earth L2 libration point mission. The Triana spacecraft was nominally to be released by the Space Shuttle in a low Earth orbit, and this analysis focuses on that scenario. From the release orbit a transfer trajectory insertion (TTI) maneuver performed using a solid stage would increase the velocity be approximately 3.1 km/sec sending Triana on a direct trajectory to its mission orbit. The Triana mission orbit is a Sun-Earth L1 Lissajous orbit with a Sun-Earth-vehicle (SEV) angle between 4.0 and 15.0 degrees, which would be achieved after a Lissajous orbit insertion (LOI) maneuver at approximately launch plus 6 months. Because Triana was to be launched by the Space Shuttle, TTI could potentially occur over a 16 orbit range from low Earth orbit. This analysis was performed assuming TTI was performed from a low Earth orbit with an inclination of 28.5 degrees and assuming support from a combination of three Deep Space Network (DSN) stations, Goldstone, Canberra, and Madrid and four commercial Universal Space Network (USN) stations, Alaska, Hawaii, Perth, and Santiago. These ground stations would provide coherent two-way range and range rate tracking data usable for orbit determination. Larger range and range rate errors were assumed for the USN stations. Nominally, DSN support would end at TTI+144 hours assuming there were no USN problems. Post-TTI coverage for a range of TTI longitudes for a given nominal trajectory case were analyzed. The orbit determination error analysis after the first correction maneuver would be generally applicable to any libration point mission utilizing a direct trajectory.
Marr, G.↗
Opals: Mission System Operations Architecture for an Optical Communications Demonstration on the ISS
In April of 2014, the Optical PAyload for Lasercomm Science (OPALS) Flight System (FS) launched to the International Space Station (ISS) to demonstrate space-to-ground optical communications. During a planned 90-day baseline mission, the OPALS FS will downlink high quality, short duration videos to the Optical Communications Telescope Laboratory (OCTL) ground station in Wrightwood, California. Interfaces to the ISS payload operations infrastructure have been established to facilitate activity planning, hazardous laser operations, commanding, and telemetry transmission. In addition, internal processes, such as pointing prediction and data processing, satisfy the technical requirements of the mission. The OPALS operations team participates in Operational Readiness Tests (ORTs) with external partners to exercise coordination processes and train for the overall mission. The ORTs have provided valuable insight into operational considerations for the instrument on the ISS.
Technology Demonstration↗
Error analysis of earth physics satellite systems
Error analysis of distant-satellite-to-close-satellite range-rate, satellite-to-sea altimetry, and ground station to satellite range are made by simulations in which observational variances are assumed, observation equations are formed, and normal equations incremented. The final normal equation matrix is inverted to obtain standard deviations and correlation coefficients. The natural parameters solved for are the broad variations of the gravity field, represented by harmonic coefficients; local variations of gravity, represented by point masses; and the departure of the sea level from the geoid, represented by area means. A standard case of a low (263 km) polar close satellite, three equatorial geosynchronous satellites, and eight ground tracking stations is set up.
Kaula, W. M.↗
The electrical characteristics of the conical horn-reflector antenna
The conical horn-reflector antenna was selected for the satellite communication ground station because of its broadband and low-noise properties. Prior to the construction of the full-size antenna, theoretical and model studies of its electrical characteristics were undertaken. These studies consisted of computing gain and radiation patterns for two modes of excitation, constructing of model antennas and measuring them. Results of these studies are presented in this paper together with results of the measurements of the full size antenna at Andover, Maine.
GROUND STATION↗
Antenna pointing system- organization and performance
This paper is a description of the antenna pointing system used in the satellite ground station at Andover, Maine. It is an introduction to the following five papers in this issue, which describe and discuss in some detail the various major parts and features of the antenna pointing system. In order that the antenna have sufficient gain for the Telstar experiment, it was necessary that it have a “pencil” beam of about 15 degree in diameter. This requires an antenna pointing system of high accuracy. The equipment and methods required to achieve this accuracy are outlined.
DIRECTIONAL CONTROL↗