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↗
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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↗
The Goonhilly 85-ft. steerable dish aerial
The choice of the basic type of aerial for a satellite communication ground station is of major importance in view of its influence on the overall performance, cost and time to complete the installation. In the case of the Post Office satellite communication earth station at Goonhilly Downs, Cornwall, a decision was made early in 1961 to use an 85-ft diameter steerable paraboloidal dish aerial, without a radome for tests with the Telstar and Relay, and other communication satellites. Tests with smaller paraboloidal dish aerials with the feed in the aperture plane had shown that a satisfactory electrical performance could be obtained, and experience with the 250-ft diameter radio telescope at Jodrell Bank had shown that the mechanical problems could be overcome. An important factor in the present case was the limited time--less than one year--available for the design, manufacture, construction and testing of the aerial.
COMMUNICATIONS SATELLITE↗
Surface climatological information for twelve selected stations for re-entry vehicles
Surface climatological information for reentry ground stations
Crutcher, H. L.↗
Baseband recording and playback
Analog recordings of spacecraft telemetry signals are made by Deep Space Network Deep Space Stations to provide backup for both spacecraft and ground station anomalies. The requirements that must be met to insure successful baseband recording and playback are given. Recording and playback procedures are developed to insure that these requirements are met and performance results from tests conducted at the Compatibility Test Area (JPL) are tabulated.
Kent, S. S.↗