OBJECT = PARAMETER INSTRUMENT_HOST_ID = 'MGN' DATA_SET_PARAMETER_NAME = 'RADAR SCALED BACKSCATTER CROSS SECTION' INSTRUMENT_PARAMETER_NAME = 'RADAR ECHO POWER' IMPORTANT_INSTRUMENT_PARMS = 1 END_OBJECT = PARAMETER OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = 'RADAR SCALED BACKSCATTER CROSS SECTION' DATA_SET_OR_INST_PARM_DESC = "Cross section values that are scaled by some procedure, such as dividing by theoretical or empirical scattering law." END_OBJECT = DSINSTPARMD OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = 'RADAR ECHO POWER' DATA_SET_OR_INST_PARM_DESC = "That part of the transmitted power scattered by the target and received by the radar antenna." END_OBJECT = DSINSTPARMD OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = 'RADIANT POWER' DATA_SET_OR_INST_PARM_DESC = "Emitted power that is received by the radar antenna." END_OBJECT = DSINSTPARMD OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = 'MGN-V-RDRS-2-EDR-SAR-V1.0' SOFTWARE_NAME = 'SDPS' PRODUCT_DATA_SET_ID = 'MGN-V-RDRS-5-BIDR-FULL-RES-V1.0' END_OBJECT = DSPROCESSING OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = 'MGN-V-RDRS-5-BIDR-FULL-RES-V1.0' SOFTWARE_NAME = 'IDPS' PRODUCT_DATA_SET_ID = 'MGN-V-RDRS-5-BIDR-COMPRESSED-V1.0' END_OBJECT = DSPROCESSING OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = 'MGN-V-RDRS-5-BIDR-COMPRESSED-V1.0' SOFTWARE_NAME = 'IDPS' PRODUCT_DATA_SET_ID = 'MGN-V-RDRS-5-MIDR-C1-V1.0' END_OBJECT = DSPROCESSING OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = 'MGN-V-RDRS-5-MIDR-C1-V1.0' SOFTWARE_NAME = 'IDPS' PRODUCT_DATA_SET_ID = 'MGN-V-RDRS-5-MIDR-C2-V1.0' END_OBJECT = DSPROCESSING OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = 'MGN-V-RDRS-5-MIDR-C2-V1.0' SOFTWARE_NAME = 'IDPS' PRODUCT_DATA_SET_ID = 'MGN-V-RDRS-5-MIDR-C3-V1.0' END_OBJECT = DSPROCESSING OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = 'MGN-V-RDRS-5-BIDR-FULL-RES-V1.0' SOFTWARE_NAME = 'IDPS' PRODUCT_DATA_SET_ID = 'MGN-V-RDRS-5-MIDR-FULL-RES-V1.0' END_OBJECT = DSPROCESSING OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = 'MGN-V-RDRS-5-BIDR-COMPRESSED-V1.0' SOFTWARE_NAME = 'IDPS' PRODUCT_DATA_SET_ID = 'MGN-V-RDRS-5-MIDR-N-POLAR-STEREOGR-V1.0' END_OBJECT = DSPROCESSING OBJECT = SOFTWARE SOFTWARE_NAME = 'SDPS' NODE_ID = 'N/A' SOFTWARE_RELEASE_DATE = 'N/A' SOFTWARE_TYPE = 'N/A' COGNIZANT_FULL_NAME = 'SDPT' SOFTWARE_ACCESSIBILITY_DESC = 'N/A' SOFTWARE_DESC = "The SAR Data Processing Subsystem (SDPS) consists of a suite of specialized routines to conduct range and Doppler compression of the radar signal, look summation, and remapping from range-Doppler to sinusoidal equal area map coordinates." END_OBJECT = SOFTWARE OBJECT = SOFTWARE SOFTWARE_NAME = 'IDPS' NODE_ID = 'N/A' SOFTWARE_RELEASE_DATE = 'N/A' SOFTWARE_TYPE = 'N/A' COGNIZANT_FULL_NAME = 'IDPT' SOFTWARE_ACCESSIBILITY_DESC = 'N/A' SOFTWARE_DESC = "The Image Data Processing Subsystem (IDPS) consists of a suite of VICAR routines, augmented with specialized modules, to ingest F-BIDRs, produce C-BIDRs, and generate MIDRs." END_OBJECT = SOFTWARE OBJECT = MISSION MISSION_NAME = 'MAGELLAN' OBJECT = MSNINFO MISSION_START_DATE = 1989-05-04 MISSION_STOP_DATE = 'UNK' MISSION_ALIAS_NAME = 'Venus Radar Mapper (VRM)' MISSION_DESC = "The Magellan spacecraft was launched from the Kennedy Space Center on May 4, 1989. The spacecraft was deployed from the Shuttle cargo bay after the Shuttle achieved parking orbit. Magellan, using an inertial upper stage rocket, was then placed into a Type IV transfer orbit to Venus. Magellan is powered by single degree of freedom, sun-tracking, solar panels. The spacecraft is 3-axis stabilized by reaction wheels using gyros and a star sensor for attitude reference. The spacecraft carried a solid rocket motor for Venus orbit insertion. A small hydrazine system provides trajectory corrections and certain attitude control functions. Earth communication with the Deep Space Network (DSN) is by means of S and X-band channels. The high-gain antenna also functions as the SAR mapping antenna during orbital operations. The interplanetary cruise phase lasted until August 10, 1990. During the cruise phase there were small trajectory correction maneuvers to insure proper approach geometry. Using the solid rocket motor, the spacecraft was placed in an elliptical orbit around the planet, with a periapsis latitude of approximately 10 degrees North, a periapsis altitude of 295 km, and a period of 3.263 hours. Apoapsis altitude is approximately 7762 km. After orbit insertion, the radar system acquired test data and then within days the signal from the spacecraft was lost twice. Placed in a 'Safe Mode', the spacecraft resumed mapping operations on September 15, 1990, after commands were relayed to avoid further communication losses. Each mapping cycle lasts 243 days, which is the time required for Venus to make one rotation under the spacecraft orbit. The first mapping cycle ended on May 15, 1991. Typical activities during a single mapping pass on cycle 1 were as follows. As the spacecraft neared the planet surface, it was oriented so the high-gain antenna pointed slightly to the side of the ground track. At a true anomaly of -59 degrees, the radar was commanded on. The radar continued to take data to a true anomaly of 80 degrees and then the radar was commanded off. On the next pass the swath started at -80 degrees and went to 59 degrees. Alternating north and south swaths were repeated during cycle 1. The range of latitude covered by the radar during cycle 1 was 67 degrees S to 90 degrees N. The range of incidence angles for the SAR was just under 20 to just over 40 degrees. The SAR data were taken at a data rate of 750 kb/s and were stored in the spacecraft tape recorder. Altimeter and radiometer data were also taken when SAR was acquired. The altimeter data were taken using the small fan beam antenna and a data rate of 30 kb/s. As the spacecraft moved away from the planet toward apoapsis, the spacecraft reoriented the high-gain antenna towards Earth and the stored radar data were transmitted to DSN stations on Earth. This data taking- and transmitting-cycle was repeated for every orbit. By May 15, 1991, the planet was completely mapped except for gaps and the area near the South Pole. Cycle 2 observations focused on filling gaps, mapping the south pole area, acquiring constant incidence angle (25 degrees) radar swaths, and conducting a suite of experiments, including high resolution imaging and acquisition of stereo data. To observe the south pole the spacecraft was rotated 180 degrees about its nadir-pointing axis to be able to conduct right-looking observations. Cycle 1 gaps were filled by rotating the spacecraft back to its initial left-looking direction. The principal objective of Cycle 3 is to perform stereo mapping of the Venusian surface. About 40 % of the Cycle 1 coverage will be mapped in this Cycle. Gravity data, over Artemis Chasma, will be obtained in Cycle 3. In addition, high resolution altimetry may be collected and a specular solar reflection radiometer experiment may be performed. Cycle 4 permits 360 degree longitudinal coverage due to the favorable planetary and spacecraft geometry; therefore extensive gravity data will be acquired. SAR sequences may also be implemented on a limited basis, targeting areas where surface changes are suspected. Prior to the start of Cycle 5, a circular orbit may be achieved. Gravity science would be the first priority in Cycle 5. Radar altimetry and imaging would benefit from the circular orbit and may also be obtained." MISSION_OBJECTIVES_SUMMARY = "VOLCANIC AND TECTONIC PROCESSES. Magellan images of the Venus surface show widespread evidence for volcanic activity. A major goal of the Magellan mission is to provide a detailed global characterization of volcanic landforms on Venus and an understanding of the mechanics of volcanism in the Venus context. Of particular interest is the role of volcanism in transporting heat through the lithosphere. While this goal will largely be accomplished by a careful analysis of images of volcanic features and of the geological relationships of these features to tectonic and impact structures, an essential aspect of characterization will be an integration of image data with altimetry and other measurements of surface properties. Explosive pyroclastic volcanism should not occur in the present Venus environment, unless the magma contains amounts of volatiles that are large by terrestrial experience. Thus, evidence for extensive pyroclastic deposits would imply the presence of large amounts of volatiles or, if the deposits are old, may suggest historic changes in atmospheric density. Such ideas will be tested using SAR and altimetry data, combined with knowledge of the local geopotential field and may shed light on magma dynamics. Measurements of longitudinal and transverse slope, flow margin relief, and flow surface relief will also provide powerful constraints on flow models, as well as on the rheological properties and physical state of the lava. A parallel goal is the global characterization of tectonic features on Venus and an appreciation of the tectonic evolution of the planet. This goal addresses issues on several scales. On the scale of individual tectonic features, we are interested in the mechanical nature of the faulting process, the documentation of geometry and sense of fault slip, and the relationship between mechanical and thermal properties of the lithosphere. On a somewhat broader scale, we are interested in linking groups of features to specific processes (e.g., uplift, orogeny, gravity sliding, flexure, compression or extension of the lithosphere) and in testing quantitative models for these processes with SAR images and supporting topographic, gravitational, and surface compositional data. On a global scale, we are interested in whether spatially coherent, large-scale patterns in tectonic behavior are discernible, patterns that might be related to an organized system of plates or to mantle convective flow. IMPACT PROCESSES. The final physical form of an impact crater has meaning only when the effects of the cratering event and any subsequent modification of the crater can be distinguished. To this end, a careful search of the SAR images will attempt to locate and document both relatively pristine and degraded impact craters, together with their ejecta deposits, in each size range, as well as to distinguish impact craters from those of volcanic origin. The topographic measures of depth-to-diameter ratio, ejecta thickness distribution as a function of distance from the crater, and the relief of central peaks will contribute to this documentation. It is expected that several time-dependent processes will influence the change in appearance of craters with increasing crater age, including continued bombardment of the surface, variations in the mechanical properties of the lithosphere (as a result of cooling or loss of near-surface volatiles), horizontal deformation of the lithosphere, possible variations in the mass of the atmosphere, volcanism, and finally, surface erosion and deposition. Distinguishing and understanding these processes constitute important components of the study of crater morphology. Beyond their intrinsic interest in providing a record of impact and deformational processes, craters provide a tool for the relative dating of surface geological units. Relative ages can be established from a comparison of the variations in the areal density of craters of a given size as well as from a comparison of the maximum extent to which different craters are degraded. Together with superpositional relationships (a lava flow that covers an older fault) and transectional relationships (a graben that cuts through an older volcano), the relative temporal evolution of large areas of the Venus surface can be reconstructed. EROSIONAL, DEPOSITIONAL, AND CHEMICAL PROCESSES. The nature of erosional and depositional processes on Venus is poorly known, primarily because of the diagnostic landforms typically occur at a scale too small to have been resolved in Earth-based or Venera 15/16 radar images. Magellan images show wind eroded terrains, landforms produced by deposition (dune fields), possible landslides and other down slope movements, as well as aeolian features such as radar bright or dark streaks 'downwind' from prominent topographic anomalies. One measure of weathering, erosion, and deposition is provided by the extent to which soil covers the surface (for Venus, the term soil is used for porous material, as implied by its relatively low value of bulk dielectric constant). The existence of such material, and its dependence on elevation and geologic setting, provide important insights into the interactions that have taken place between the atmosphere and the lithosphere. Because of the inference drawn from the deuterium-to-hydrogen ratio of the present atmosphere for the past existence of substantial amounts of water on Venus, the images continue to be searched for evidence of past episodes of fluvial activity (drainage systems) and for lake beds and coastal signatures (strandlines). The existence of a thick and cloudy atmosphere precludes infrared, visual, ultraviolet, x-ray, or gamma-ray observation of the Venus surfaces from orbit. Thus it is impossible to obtain information on a global basis about the surface composition of mineralogy using standard remote-sensing techniques. Magellan data have disclosed that very often the surfaces of elevated regions possess both anomalously high values of normal-incidence radar reflectivity, occasionally exceeding 0.43, and associated low values of radio emissivity, reaching as low as 0.50. In the absence of liquid water, which is known from a variety of evidence not to be present today on Venus, it is necessary to assume a surface composition that would be unusual in terrestrial experience to explain the large values of dielectric constant implied by these observations. The most acceptable of the current hypotheses requires a significant number of electrically conducting elements in surface materials. If these are iron sulfides, as some chemical evidence suggests, they may possibly be brought to the surface by volcanic activity. The good spatial resolution of the Magellan instrumentation, both in determining the surface reflectivity from the altimetric observations and in measuring the emissivity from radiometric observations, promises to outline the structure of these regions in far greater detail than is now available and may shed light on their origin. Results will be applied to testing hypotheses for regional and global buffering of atmospheric composition by reactions with crustal materials. ISOSTATIC AND CONVECTIVE PROCESSES. Topography and gravity are intimately and inextricably related, and must be jointly examined when undertaking geophysical investigations of the interior of a planet, where isostatic and convective processes dominate. Topography provides a surface boundary condition for modeling the interior density of Venus. Modeling of the interior density using gravity data is, of course, nonunique. Meaningful interpretation rests on integrating other data sets and/or incorporating specific mechanical models of the interior. For example, a single density interface underlying the known topography can be found that exactly matches any observed gravity field. The interface can be at any depth; the greater the depth, the larger the density contrast needed. The thickness of the elastic lithosphere of Venus, i.e., the outer region of the planet that behaves elastically over geologically long periods of time, is of special interest. The base of this zone is likely to be defined by a specific isotherm whose location depends on the particular temperature-dependent flow or creep properties of the material underneath. If this isotherm can be mapped in space and time, then models for the thermal evolution of the planet can be developed. The key to determining lithospheric thickness variations in space and time is through flexure studies. If a mass load, e.g., a shield volcano or a mascon, is placed on the planetary surface, then the elastic lithosphere will flex under the load. The controlling parameter is the flexural rigidity, which is dependent on the elastic constants and lithospheric thickness. Crucial to applying estimates of flexural rigidity to the task of unraveling the thermal history is an estimate of when the load was emplaced. Thus age determinations derived by various geologic techniques are essential to this scheme." OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'PRELAUNCH' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1988-09-01 MISSION_PHASE_STOP_TIME = 1989-05-04 MISSION_PHASE_DESC = "The prelaunch phase extended from delivery of the spacecraft to Kennedy Space Center until the start of the launch countdown." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'LAUNCH' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1989-05-04 MISSION_PHASE_STOP_TIME = 1989-05-04 MISSION_PHASE_DESC = "The launch phase extended from the start of launch countdown until completion of the injection into Earth-Venus trajectory." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'CRUISE' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1989-05-04 MISSION_PHASE_STOP_TIME = 1990-08-01 MISSION_PHASE_DESC = "The cruise phase extended from injection into an Earth-Venus trajectory until Venus orbit insertion minus 10 days." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'ORBIT INSERTION' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1990-08-01 MISSION_PHASE_STOP_TIME = 1990-08-10 MISSION_PHASE_DESC = "The Venus orbit insertion phase extended from Venus orbit insertion minus 10 days until burnout of the solid rocket injection motor." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'ORBIT CHECKOUT' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1990-08-10 MISSION_PHASE_STOP_TIME = 1990-09-15 MISSION_PHASE_DESC = "Orbit trim and checkout phase extended from burnout of the solid rocket injection motor until beginning of the mapping." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'MAPPING CYCLE 1' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1990-09-16 MISSION_PHASE_STOP_TIME = 1991-05-15 MISSION_PHASE_DESC = "The first mapping cycle extends from completion of the orbit trim and checkout phase until completion of one cycle of mapping (approximately 243 days)." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'MAPPING CYCLE 2' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1991-05-16 MISSION_PHASE_STOP_TIME = 1992-01-13 MISSION_PHASE_DESC = "The second mapping cycle extends from completion of the first mapping cycle until completion of one cycle of mapping (approximately 243 days)." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'MAPPING CYCLE 3' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1992-01-14 MISSION_PHASE_STOP_TIME = 1992-09-13 MISSION_PHASE_DESC = "The third mapping cycle extends from completion of the second mapping cycle until completion of one cycle of mapping (approximately 243 days)." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'MAPPING CYCLE 4' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1992-09-14 MISSION_PHASE_STOP_TIME = 1993-05-14 MISSION_PHASE_DESC = "The fourth mapping cycle extends from completion of the third mapping cycle until completion of one cycle of mapping (approximately 243 days)." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = 'MGN' TARGET_NAME = 'VENUS' MISSION_PHASE_TYPE = 'MAPPING CYCLE 5' SPACECRAFT_OPERATIONS_TYPE = 'ORBITER' MISSION_PHASE_START_TIME = 1993-05-15 MISSION_PHASE_STOP_TIME = 1994-01-12 MISSION_PHASE_DESC = "The fifth mapping cycle extends from completion of the fourth mapping cycle until completion of one cycle of mapping (approximately 243 days)." END_OBJECT = MSNPHSINFO END_OBJECT = MSNINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'SAUNDERSETAL1990' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION SCIENCE' JOURNAL_NAME = 'JOURNAL OF GEOPHYSICAL RESEARCH' PUBLICATION_DATE = 1990-06-10 REFERENCE_DESC = "Saunders, R.S., G.H. Pettengill, R.E. Arvidson, W.L. Sjogren, W.T.K. Johnson, L. Pieri, The Magellan Venus Radar Mapping Mission, Journal of Geophysical Research, vol. 95, no. B6, pp. 8339-8355, June 10, 1990." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. STEPHEN SAUNDERS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'GORDON H. PETTENGILL' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'RAYMOND E. ARVIDSON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'W. L. SJOGREN' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'WILLIAM T. K. JOHNSON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'LESLIE J. PIERI' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'VRMPP1983' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MAGELLAN PROJECT DOCUMENT' JOURNAL_NAME = 'N/A' PUBLICATION_DATE = 1983-11-01 REFERENCE_DESC = "Venus Radar Mapper Project Plan, Document 630-1, JPL D-814, 157 pp., Jet Propulsion Laboratory, Pasadena, Calif., 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'N/A' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'PETTENGILL1988' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MAGELLAN PROJECT DOCUMENT' JOURNAL_NAME = 'N/A' PUBLICATION_DATE = 1988 REFERENCE_DESC = "Pettengill, G. H., Magellan Venus Radar Mapper Science Experiment Plan of the Radar Investigation Group (RADIG), MIT/JPL." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. H. PETTENGILL' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'SAUNDERS1991A' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION DESCRIPTION' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Saunders, R. S., Pettengill, G. H., Magellan: Mission Summary, Science, V. 252, pp. 247 - 249, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. S. SAUNDERS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. H. PETTENGILL' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'SAUNDERS1991B' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Saunders, R. S., Arvidson, R. E., Head III, J. W., Schaber, G. G., Stofan, E. R., Solomon, S. C., An Overview of Venus Geology, Science, V. 252, pp. 249 - 252, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. S. SAUNDERS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. E. ARVIDSON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. W. HEAD III' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. G. SCHABER' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'E. R. STOFAN' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'S. C. SOLOMON' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'SOLOMON1991A' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Solomon, S. C., Head, J. W., Fundamental Issues in the Geology of Venus, Science, V. 252, pp. 252 - 260, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'S. C. SOLOMON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. W. HEAD' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'PETTENGILL1991' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Pettengill, G. H., Ford, P. G., Johnson, W. T. K., Raney, R. K., Soderblom, L. A., Magellan: Radar Performance and Data Products, Science, V. 252, pp. 260 - 265, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. H. PETTENGILL' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'P. G. FORD' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'W. T. K. JOHNSON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. K. RANEY' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'L. A. SODERBLOM' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'TYLER1991' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Tyler, G. L., Ford, P. G., Campbell, D. B., Elachi, C., Pettengill, G. H., Simpson, R. A., Magellan: Electrical and Physical Properties of Venus' Surface, Science, V. 252, pp. 265 - 270, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. L. TYLER' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'P. G. FORD' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'D. B. CAMPBELL' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'C. ELACHI' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. H. PETTENGILL' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. A. SIMPSON' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'ARVIDSON1991' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Arvidson, R. E., Baker, V. R., Elachi, C., Saunders, R. S., Wood, J. A., Magellan: Initial Analysis of Venus Surface Modification, Science, V. 252, pp. 270 - 275, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. E. ARVIDSON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'V. R. BAKER' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'C. ELACHI' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. S. SAUNDERS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. A. WOOD' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'HEAD1991' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Head, J. W., Campbell, D. B., Elachi, C., Guest, J. E., McKenzie, D. P., Saunders, R. S., Schaber, G. G., Schubert, G., Venus Volcanism: Initial Analysis from Magellan Data, Science, V. 252, pp. 276 - 288, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. W. HEAD' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'D. B. CAMPBELL' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'C. ELACHI' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. E. GUEST' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'D. P. MCKENZIE' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. S. SAUNDERS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. G. SCHABER' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. SCHUBERT' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'PHILLIPS1991' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Phillips, R. J., Arvidson, R. E., Boyce, J. M., Campbell, D. B., Guest, J. E., Schaber, G. G., Soderblom, L. A., Impact craters on Venus: Initial Analysis from Magellan, Science, V. 252, pp. 288 - 297, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. J. PHILLIPS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. E. ARVDISON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. M. BOYCE' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'D. B. CAMPBELL' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. E. GUEST' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. G. SCHABER' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'L. A. SODERBLOM' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = 'SOLOMON1991B' OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = 'MISSION RESULTS' JOURNAL_NAME = 'SCIENCE' PUBLICATION_DATE = 1991-04-12 REFERENCE_DESC = "Solomon, S. C., Head, J. W., Kaula, W. M., McKenzie, D., Parsons, B., Phillips, R. J., Schubert, G., Talwani, M., Venus Tectonics: Initial Analysis from Magellan, Science, V. 252, pp. 297 - 312, 1991" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'S. C. SOLOMON' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'J. W. HEAD' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'W. M. KAULA' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'D. MCKENZIE' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'B. PARSONS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'R. J. PHILLIPS' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'G. SCHUBERT' END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = 'M. TALWANI' END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO END_OBJECT = MISSION OBJECT = SPACECRAFT SPACECRAFT_ID = 'MGN' OBJECT = SCINFO LAUNCH_DATE = 1989-05-04 INSTRUMENT_HOST_NAME = 'MAGELLAN' INSTRUMENT_HOST_TYPE = 'SPACECRAFT' SPACECRAFT_DESC = "The design of the Magellan spacecraft was driven by the need for a low-cost, high-performance vehicle. Some of the Magellan spacecraft components were already in existence or at least designed. Protoflight spacecraft were available from storage at no cost. These include the 3.7 meter diameter, high-gain antenna (HGA), the spacecraft bus, propulsion system components, thermal control louvers, and much of the radio subsystem. The stockpile of flight spares for the Galileo spacecraft provided Magellan's command and data system, tape recorders, attitude control processor, power subsystem and propulsion components. Further elements were drawn from other projects and from NASA standard designs. Only about 30% (by mass) of the Magellan spacecraft was especially designed for the mission, primarily the radar electronics and the solar panels. The spacecraft system was built by Martin Marietta Corporation. The spacecraft system is composed of the structure, thermal control, power, attitude control, propulsion, command data and data storage, and telecommunications subsystems. The spacecraft structure is composed of four major sections: High-Gain Antenna (HGA), Forward Equipment Module (FEM), Spacecraft Bus (including the solar array), and the Orbit Insertion Stage. The High-Gain antenna is used as the antenna for the SAR and as the primary antenna for the telecommunications system. The radar electronics, the reaction wheels, and various other spacecraft subsystem components are contained within the Forward Equipment Module, located between the bay and the HGA. The spacecraft bus is a ten sided structure that contains remainder of the spacecraft subsystem components including the solar panel array, star scanner, medium-gain antenna (MGA), rocket engine modules (REMs), command, data and data storage (CDDS) subsystem, attitude control monopropellant tank, and a nitrogen tank for providing propellant pressurization. The orbit insertion stage contains a STAR-48 solid rocket motor (SRM) that is used to provide the impulse required to perform the Venus Orbit Insertion (VOI) maneuver. Thermal control of the spacecraft is accomplished by a combination of louvers, thermal blankets, passive coatings, and heat dissipating elements. The nominal operating temperature for the spacecraft components is between -5 and +40 degrees Centigrade. The thermal control subsystem maintains these components at the appropriate temperatures for all orientations of the spacecraft orbit and sun- line and for all spacecraft operating modes. Electrical power is supplied by two large solar panels with a total area of 12.6 square meters. This array is capable of producing a minimum power of 1029 W at the end of the nominal mission, and has a single degree of freedom about the solar array axis to allow tracking of the Sun despite the changing Earth-Sun-spacecraft geometry during the mission. A dedicated sun sensor optimizes power production. Bus voltage regulation is controlled by the power control unit (PCU) with a shunt regulator for diverting excess power from the solar arrays to maintain power as raw power (28-35 v), regulated power at 28 vDC +/-0.56 vDC, and as AC at 2.4 KHz through the inverter. Two 30 amp-hour, 26-cell nickel cadmium batteries provide power during times of solar occultation, and allow normal spacecraft operations independent of real-time solar illumination. These batteries are sized to allow a degraded mission in the event that one of them fails. The attitude of the Magellan spacecraft is controlled through the use of reaction wheels, with monopropellant rocket motors being used to periodically desaturate the reaction wheels. During both the interplanetary cruise and the orbital portions of the mission, attitude reference is provided by an inertial reference unit (IRU) which is updated each orbit using celestial references. During the mapping phase of the orbit, the spacecraft is initially oriented with the HGA pointing down toward Venus, with the exact attitude being a function of the spacecraft altitude. During the downlink transmission phase of the orbit, the spacecraft is oriented with the HGA slightly off the Earth-line. The low gain antenna (LGA) is mounted coaxially with the HGA and does not require pointing since it has an omnidirectional beam pattern. The altimeter horn (ALTA) has been positioned so that a portion of the fan-shaped beam always points in the nadir direction during the mapping phase of an orbit. The Magellan propulsion subsystem consists of two parts. The first, a Star 48 SRM, provides the impulse for VOI. Following that maneuver, the empty casing and parts of its support structure were ejected from the spacecraft. The second part consists of monopropellant hydrazine thrusters that were used for trajectory correction maneuvers (TCMs) during interplanetary cruise, thrust vector control (TVC) during VOI, orbit trim maneuvers during the mapping mission, and attitude control when the action wheels are being desaturated. The rocket motors are clustered in modules located on the end of outrigger booms in order to increase their moment arm and thus decrease attitude control propellant requirements. Twelve 0.9-N (Newton) and four 22-N rocket motors are used for attitude control, with thrust being provided by eight 445-N rocket motors or by the 0.9-N motors for small TCMs. All engines point in the -Z direction, with the exception of the roll motors. The 0.9-N motors were used for tip-off control following separation of the inertial upper stage (IUS), reaction wheel desaturation, roll control for all times other than VOI, to back up any failed reaction wheels, and for small TCMs or orbit trim maneuvers (OTMs). The 22-N motors were used for roll control during VOI. The 445-N motors were used for controlling the spacecraft rotational axis during VOI, and to provide impulses during all propulsive maneuvers. The monopropellant motors also provided the impulses needed to trim the VOI maneuver. The command, data and data storage (CDDS) system is responsible for receiving uplink commands via the radio frequency subsystem (RFS) and controlling the spacecraft in response to those commands. It is also responsible for controlling the acquisition and storage of scientific data and sending that data, along with supplemental engineering data, to the RFS for downlink transmission to Earth. The commands are sent to the spacecraft as time-event pairs for storage and later execution, and also in the form of blocks which the CDDS later expands into spacecraft executable commands. In the Venus orbit phase, commands for up to three days of radar operations are stored. The provision also exists to receive and execute discrete commands sent up from the ground. Engineering data is nominally transmitted to Earth over a real-time S-band link. During those times when real-time link is not possible, the data is tape recorded and played back via the X-band high-rate link. The SAR data are nominally stored on two multi-track digital tape records (DTRs) for later playback over the high-rate X-band link. There is no provision for real-time transmission of the SAR data. Data storage capacity of the two DTRs is approximately 1.8 billion bits. These DTRs are primarily used for recording SAR data, although low- rate engineering data can be stored on these devices, interleaved with the SAR data, during times when those data cannot be transmitted to Earth over a real-time link. The recorded data stream will alternately be switched between these two DTRs so that the data will not be lost during the DTR track change. The Magellan telecommunications subsystem contains all the hardware necessary to maintain communications between Earth and the spacecraft. The subsystem contains the radio frequency subsystem, the LGA, MGA, and HGA. The RFS performs the functions of carrier transponding, command detection and decoding, and telemetry modulation. The spacecraft is capable of simultaneous X-band and S- band uplink and downlink operations. The S-band operates at a transmitter power of 5 W, while the X-band operates at a power of 22 W. Uplink data rates are 31.25 and 62.5 bps (bits per second) with downlink data rates of 40 bps (emergency only), 1200 bps (real-time engineering rate), 115.2 kbps (kilobits per second) (radar downlink backup), and 268.8 kbps (nominal)." END_OBJECT = SCINFO OBJECT = PLATFORM PLATFORM_OR_MOUNTING_NAME = 'SPACECRAFT' PLATFORM_OR_MOUNTING_DESC = "The radar system is mounted onto the spacecraft." END_OBJECT = PLATFORM OBJECT = SCREFINFO REFERENCE_KEY_ID = 'SAUNDERSETAL1990' END_OBJECT = SCREFINFO END_OBJECT = SPACECRAFT OBJECT = SCINSTRUMENT SPACECRAFT_ID = 'MGN' INSTRUMENT_ID = 'RDRS' OBJECT = INSTINFO INSTRUMENT_NAME = 'RADAR SYSTEM' INSTRUMENT_TYPE = 'RADAR' PI_PDS_USER_ID = 'GPETTENGILL' NAIF_DATA_SET_ID = 'UNK' BUILD_DATE = 1989-01-01 INSTRUMENT_MASS = 126.1 INSTRUMENT_HEIGHT = 0.304 INSTRUMENT_LENGTH = 1.35 INSTRUMENT_WIDTH = 0.902 INSTRUMENT_MANUFACTURER_NAME = "Hughes Aircraft Company" INSTRUMENT_SERIAL_NUMBER = 'N/A' INSTRUMENT_DESC = "Radar system includes a 3.7 m diameter high gain antenna (HGA) for SAR and radiometry and smaller fan-beam antenna (ALTA) for altimetry. The system operates at 12.6 cm wavelength and shares common electronics. Between SAR bursts, typically several times a second, groups of altimeter pulses are transmitted from a dedicated fan-beam altimeter antenna directed toward the spacecraft's nadir. The altimeter pulses are identical in waveform and bandwidth to the SAR pulses, resulting in a range accuracy of better than 15 m. The pulse-repetition rate and burst duration differ between the two modes. Radiometry data are obtained by spending a portion of the time between SAR bursts in a passive mode, with the HGA antenna recording the power emitted from the planet." SCIENTIFIC_OBJECTIVES_SUMMARY = "See MISSION_OBJECTIVES_SUMMARY under MISSION." INSTRUMENT_CALIBRATION_DESC = "Calibrated before flight using active electronic target simulator." OPERATIONAL_CONSID_DESC = "The Magellan radar system is used to acquire altimetry, radiometry, and radar backscatter (SAR) images when the spacecraft is close to the planet. Near apoapsis the SAR antenna is pointed toward Earth and used to telemeter data to the DSN." END_OBJECT = INSTINFO OBJECT = INSTDETECT DETECTOR_ID = 'N/A' DETECTOR_TYPE = 'N/A' DETECTOR_ASPECT_RATIO = 'N/A' MINIMUM_WAVELENGTH = 'N/A' MAXIMUM_WAVELENGTH = 'N/A' NOMINAL_OPERATING_TEMPERATURE = 'N/A' DETECTOR_DESC = "Not applicable" SENSITIVITY_DESC = "Not applicable" END_OBJECT = INSTDETECT OBJECT = INSTELEC ELECTRONICS_ID = 'RDRS' ELECTRONICS_DESC = "The Magellan radar system consists of a high gain antenna, a smaller fan beam antenna, and shared electronics. Electronics package includes modules to command and control acquisition of altimetry, radiometry and SAR backscatter data." END_OBJECT = INSTELEC OBJECT = INSTFILTER FILTER_NUMBER = 'N/A' FILTER_NAME = 'N/A' FILTER_TYPE = 'N/A' MINIMUM_WAVELENGTH = 'N/A' CENTER_FILTER_WAVELENGTH = 'N/A' MAXIMUM_WAVELENGTH = 'N/A' MEASUREMENT_WAVE_CALBRT_DESC = "Not applicable" END_OBJECT = INSTFILTER OBJECT = INSTOPTICS TELESCOPE_ID = 'N/A' TELESCOPE_FOCAL_LENGTH = 'N/A' TELESCOPE_DIAMETER = 'N/A' TELESCOPE_F_NUMBER = 'N/A' TELESCOPE_RESOLUTION = 'N/A' TELESCOPE_TRANSMITTANCE = 'N/A' TELESCOPE_T_NUMBER = 'N/A' TELESCOPE_T_NUMBER_ERROR = 'N/A' TELESCOPE_SERIAL_NUMBER = 'N/A' OPTICS_DESC = "Not applicable" END_OBJECT = INSTOPTICS OBJECT = SCINSTOFFSET PLATFORM_OR_MOUNTING_NAME = 'SPACECRAFT' CONE_OFFSET_ANGLE = 0 CROSS_CONE_OFFSET_ANGLE = 0 TWIST_OFFSET_ANGLE = 0 INSTRUMENT_MOUNTING_DESC = "Antennas are mounted to the spacecraft body." END_OBJECT = SCINSTOFFSET OBJECT = INSTSECTION SECTION_ID = 'RAD' OBJECT = INSTSECTINFO SCAN_MODE_ID = '750 kbps' DATA_RATE = 750000 SAMPLE_BITS = 'N/A' TOTAL_FOVS = 'N/A' OBJECT = INSTSECTFOVS FOV_SHAPE_NAME = 'N/A' HORIZONTAL_PIXEL_FOV = 'N/A' VERTICAL_PIXEL_FOV = 'N/A' HORIZONTAL_FOV = 'N/A' VERTICAL_FOV = 'N/A' FOVS = 'N/A' END_OBJECT = INSTSECTFOVS END_OBJECT = INSTSECTINFO OBJECT = INSTSECTPARM INSTRUMENT_PARAMETER_NAME = 'RADIANT POWER' MINIMUM_INSTRUMENT_PARAMETER = 'N/A' MAXIMUM_INSTRUMENT_PARAMETER = 'N/A' NOISE_LEVEL = 'UNK' INSTRUMENT_PARAMETER_UNIT = 'WATTS' SAMPLING_PARAMETER_NAME = 'TIME' MINIMUM_SAMPLING_PARAMETER = 'N/A' MAXIMUM_SAMPLING_PARAMETER = 'N/A' SAMPLING_PARAMETER_INTERVAL = 'N/A' SAMPLING_PARAMETER_RESOLUTION = 'N/A' SAMPLING_PARAMETER_UNIT = 'SECOND' END_OBJECT = INSTSECTPARM OBJECT = INSTSECTDET DETECTOR_ID = 'N/A' END_OBJECT = INSTSECTDET OBJECT = INSTSECTELEC ELECTRONICS_ID = 'RDRS' END_OBJECT = INSTSECTELEC OBJECT = INSTSECTFILT FILTER_NUMBER = 'N/A' END_OBJECT = INSTSECTFILT OBJECT = INSTSECTOPTC TELESCOPE_ID = 'N/A' END_OBJECT = INSTSECTOPTC END_OBJECT = INSTSECTION OBJECT = INSTSECTION SECTION_ID = 'SAR' OBJECT = INSTSECTINFO SCAN_MODE_ID = '750 kbps' DATA_RATE = 750000 SAMPLE_BITS = 'N/A' TOTAL_FOVS = 'N/A' OBJECT = INSTSECTFOVS FOV_SHAPE_NAME = 'N/A' HORIZONTAL_PIXEL_FOV = 'N/A' VERTICAL_PIXEL_FOV = 'N/A' HORIZONTAL_FOV = 'N/A' VERTICAL_FOV = 'N/A' FOVS = 'N/A' END_OBJECT = INSTSECTFOVS END_OBJECT = INSTSECTINFO OBJECT = INSTSECTPARM INSTRUMENT_PARAMETER_NAME = 'RADAR ECHO POWER' MINIMUM_INSTRUMENT_PARAMETER = 'N/A' MAXIMUM_INSTRUMENT_PARAMETER = 'N/A' NOISE_LEVEL = 'UNK' INSTRUMENT_PARAMETER_UNIT = 'WATTS' SAMPLING_PARAMETER_NAME = 'TIME' MINIMUM_SAMPLING_PARAMETER = 'N/A' MAXIMUM_SAMPLING_PARAMETER = 'N/A' SAMPLING_PARAMETER_INTERVAL = 'N/A' SAMPLING_PARAMETER_RESOLUTION = 'N/A' SAMPLING_PARAMETER_UNIT = 'SECOND' END_OBJECT = INSTSECTPARM OBJECT = INSTSECTDET DETECTOR_ID = 'N/A' END_OBJECT = INSTSECTDET OBJECT = INSTSECTELEC ELECTRONICS_ID = 'RDRS' END_OBJECT = INSTSECTELEC OBJECT = INSTSECTFILT FILTER_NUMBER = 'N/A' END_OBJECT = INSTSECTFILT OBJECT = INSTSECTOPTC TELESCOPE_ID = 'N/A' END_OBJECT = INSTSECTOPTC END_OBJECT = INSTSECTION OBJECT = INSTSECTION SECTION_ID = 'ALT' OBJECT = INSTSECTINFO SCAN_MODE_ID = '35 kbps' DATA_RATE = 35000 SAMPLE_BITS = 'N/A' TOTAL_FOVS = 'N/A' OBJECT = INSTSECTFOVS FOV_SHAPE_NAME = 'N/A' HORIZONTAL_PIXEL_FOV = 'N/A' VERTICAL_PIXEL_FOV = 'N/A' HORIZONTAL_FOV = 'N/A' VERTICAL_FOV = 'N/A' FOVS = 'N/A' END_OBJECT = INSTSECTFOVS END_OBJECT = INSTSECTINFO OBJECT = INSTSECTPARM INSTRUMENT_PARAMETER_NAME = 'RADAR ECHO POWER' MINIMUM_INSTRUMENT_PARAMETER = 'N/A' MAXIMUM_INSTRUMENT_PARAMETER = 'N/A' NOISE_LEVEL = 'UNK' INSTRUMENT_PARAMETER_UNIT = 'WATTS' SAMPLING_PARAMETER_NAME = 'TIME' MINIMUM_SAMPLING_PARAMETER = 'N/A' MAXIMUM_SAMPLING_PARAMETER = 'N/A' SAMPLING_PARAMETER_INTERVAL = 'N/A' SAMPLING_PARAMETER_RESOLUTION = 'N/A' SAMPLING_PARAMETER_UNIT = 'SECOND' END_OBJECT = INSTSECTPARM OBJECT = INSTSECTDET DETECTOR_ID = 'N/A' END_OBJECT = INSTSECTDET OBJECT = INSTSECTELEC ELECTRONICS_ID = 'RDRS' END_OBJECT = INSTSECTELEC OBJECT = INSTSECTFILT FILTER_NUMBER = 'N/A' END_OBJECT = INSTSECTFILT OBJECT = INSTSECTOPTC TELESCOPE_ID = 'N/A' END_OBJECT = INSTSECTOPTC END_OBJECT = INSTSECTION OBJECT = INSTMODEINFO INSTRUMENT_MODE_ID = 'RADIOMETRY' GAIN_MODE_ID = 'N/A' DATA_PATH_TYPE = 'RECORDED DATA PLAYBACK' INSTRUMENT_POWER_CONSUMPTION = 'UNK' INSTRUMENT_MODE_DESC = "Radiometry data are obtained by the high gain antenna (HGA) in a receive-only mode that is activated after the altimetry mode to record the level of radiothermal power emitted by the surface of the planet. Noise power within the 10-MHz receiver bandwidth is detected and accumulated for 50 ms. To reduce the sensitivity to receiver gain changes in this mode, the receiver is connected on alternate bursts first to a comparison dummy load at a known physical temperature and then to the HGA. The short-term temperature resolution is about 2 K; the long-term absolute accuracy after calibration should be about 20 K." OBJECT = INSTMODESECT SECTION_ID = 'RAD' END_OBJECT = INSTMODESECT END_OBJECT = INSTMODEINFO OBJECT = INSTMODEINFO INSTRUMENT_MODE_ID = 'SAR' GAIN_MODE_ID = 'N/A' DATA_PATH_TYPE = 'RECORDED DATA PLAYBACK' INSTRUMENT_POWER_CONSUMPTION = 'UNK' INSTRUMENT_MODE_DESC = "This mode utilizes the Synthetic Aperture Radar (SAR) feature of the radar instrumentation. Multiple looks are acquired to reduce speckle. Signal to Noise ratio is required to exceed 8 dB. Incidence Angle varies from 13 degrees at the pole to about 44 degrees at periapsis." OBJECT = INSTMODESECT SECTION_ID = 'SAR' END_OBJECT = INSTMODESECT END_OBJECT = INSTMODEINFO OBJECT = INSTMODEINFO INSTRUMENT_MODE_ID = 'ALTIMETRY' GAIN_MODE_ID = 'N/A' DATA_PATH_TYPE = 'RECORDED DATA PLAYBACK' INSTRUMENT_POWER_CONSUMPTION = 'UNK' INSTRUMENT_MODE_DESC = "After SAR bursts, typically several times a second, groups of altimeter pulses are transmitted from a dedicated fan beam altimeter antenna (ALTA) directed toward the spacecraft's nadir. The altimetric echoes are processed to yield altimetric and surface scattering information covering at least 70% of the planet." OBJECT = INSTMODESECT SECTION_ID = 'ALT' END_OBJECT = INSTMODESECT END_OBJECT = INSTMODEINFO OBJECT = INSTREFINFO REFERENCE_KEY_ID = 'SAUNDERSETAL1990' END_OBJECT = INSTREFINFO END_OBJECT = SCINSTRUMENT OBJECT_NAME = PERSON PDS_USER_ID = GPETTENGILL OBJECT_NAME = PERSINFO FTS_NUMBER = 'N/A' FULL_NAME = 'DR. GORDEN H. PETTENGILL' LAST_NAME = PETTENGILL TELEPHONE_NUMBER = '617-253-4281' REGISTRATION_DATE = 1991-02-27 MAILING_ADDRESS_LINE = "MASSACHUSETTS INSTITUTE OF TECHNOLOGY \n CENTER FOR SPACE RESEARCH \n BLDG 37 ROOM 641 \n CAMBRIDGE, MA 02139" END_OBJECT = PERSINFO OBJECT_NAME = PERSORDER BILLING_ADDRESS_LINE = "MASSACHUSETTS INSTITUTE OF TECHNOLOGY \n CENTER FOR SPACE RESEARCH \n BLDG 37 ROOM 641 \n CAMBRIDGE, MA 02139" PERSONNEL_SHIPPING_CARRIER_NAM= 'N/A' PERSONNEL_SHIPPING_ACCOUNT_NUM= 'N/A' ORDER_PREFERENCE_ID = 'N/A' END_OBJECT = PERSORDER OBJECT_NAME = PERSELECMAIL ELECTRONIC_MAIL_ID = GPETTENGILL ELECTRONIC_MAIL_TYPE = 'NASAMAIL' PREFERENCE_ID = 1 END_OBJECT = PERSELECMAIL OBJECT_NAME = PERSINSTN PERSON_INSTITUTION_NAME = 'MASSACHUSETTS INSTITUTE OF TECHNOLOGY' END_OBJECT = PERSINSTN OBJECT_NAME = PERSNODE NODE_ID = 'GEOSCIENCE' END_OBJECT = PERSNODE OBJECT_NAME = PERSMSN MISSION_NAME = 'MAGELLAN' SPACECRAFT_ID = 'MGN' INSTRUMENT_ID = 'RDRS' EXPERTISE_AREA_TYPE = 'SCIENCE' SPECIALTY_DESC = 'PRINCIPAL INVESTIGATOR' ROLE_DESC = 'SYNTHETIC APERATURE RADAR' END_OBJECT = PERSMSN OBJECT_NAME = PERSTASK TASK_NAME = 'N/A' EXPERTISE_AREA_TYPE = 'N/A' SPECIALTY_DESC = 'N/A' ROLE_DESC = 'N/A' END_OBJECT = PERSTASK END_OBJECT = PERSON END