{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,14]],"date-time":"2026-05-14T09:16:37Z","timestamp":1778750197208,"version":"3.51.4"},"reference-count":21,"publisher":"American Geophysical Union (AGU)","issue":"E8","license":[{"start":{"date-parts":[[2012,9,21]],"date-time":"2012-09-21T00:00:00Z","timestamp":1348185600000},"content-version":"vor","delay-in-days":7332,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Geophys. Res."],"published-print":{"date-parts":[[1992,8,25]]},"abstract":"<jats:p>Before the Magellan mission, the best estimates of the rotation rate and pole direction of Venus were derived from Earth\u2010based radar measurements. A new determination of these rotational parameters has now been made from an analysis of Magellan radar images. Control points were selected from the north polar region and measured on full\u2010resolution radar strips. The measurements were entered into a least squares adjustment to solve for the pole direction and rotation rate of Venus, as well as the coordinates of the control points themselves. The current data set contains 3893 measurements of 571 points on 560 radar strips. Spacecraft ephemeris errors dominate the measurement errors. One technique used to remove ephemeris errors is to adjust the averaged orbital inclination and argument of periapsis for each orbit. In a more precise technique used for selected blocks of orbits, an improved spacecraft ephemeris is computed by optimally fitting measurements of additional points at all latitudes of the radar strips together with Earth\u2010based spacecraft radiometric tracking measurements. In a separate experiment, measurements were made of a few points common to both Venera 15\/16 and Magellan images. The long time baseline between the images should have led to an accurate determination of the rotation period and pole direction of Venus. However, the measurement residuals were unexpectedly large, and these solutions are not currently considered reliable. A rotation period estimate of 243.0185 \u00b1 0.0001 days was determined via the ephemeris improvement technique applied simultaneously to two overlapping orbit blocks with many common points and separated by two full Venus rotations. Using this period value, the control network computations estimated the north pole direction as right ascenson = 272.76\u00b0 \u00b1 0.02\u00b0 and declination = 67.16\u00b0 \u00b1 0.01\u00b0 in the J2000 frame.<\/jats:p>","DOI":"10.1029\/92je01166","type":"journal-article","created":{"date-parts":[[2009,5,8]],"date-time":"2009-05-08T19:45:38Z","timestamp":1241811938000},"page":"13141-13151","source":"Crossref","is-referenced-by-count":32,"title":["The rotation period, direction of the North Pole, and geodetic control network of Venus"],"prefix":"10.1029","volume":"97","author":[{"given":"M. E.","family":"Davies","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"T. R.","family":"Colvin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P. G.","family":"Rogers","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P. W.","family":"Chodas","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"W. L.","family":"Sjogren","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E. L.","family":"Akim","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"V. A.","family":"Stepanyantz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Z. P.","family":"Vlasova","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A. I.","family":"Zakharov","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"13","published-online":{"date-parts":[[2012,9,21]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1086\/109220"},{"key":"e_1_2_1_3_1","unstructured":"Chodas P. W. T. C.Wang W. L.Sjogren J. E.Ekelund Magellan ephemeris improvement using synthetic aperture radar landmark measurementspaper AAS 91\u2013391 presented at AAS\/AIAA Astrodynamics Specialist ConferenceDurango Colorado 1991."},{"key":"e_1_2_1_4_1","unstructured":"Colvin T. R. Radargrammetric algorithms and software for use with data from MagellanRep. N\u20103221RAND Corp. Santa Monica Calif. 1990."},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF01228525"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF01232291"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF00053048"},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1086\/110231"},{"key":"e_1_2_1_9_1","unstructured":"Engelhardt D. B. C. M.Diarra D. T.Lyons M. S.Ryne Interleaving Magellan altimetry data acquisition between mapping cycles 1 and 2paper AAS 91\u2013390 presented at AAS\/AIAA Astrodynamics Specialist ConferenceDurango Colorado 1991."},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1029\/92JE01085"},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1086\/109221"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1029\/RS005i002p00435"},{"issue":"1","key":"e_1_2_1_13_1","first-page":"107","article-title":"A gravity field to support Magellan navigation and science at Venus","volume":"40","author":"McNamee J. B.","year":"1992","journal-title":"J. Astron. Sci."},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1086\/108692"},{"key":"e_1_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.1086\/110229"},{"key":"e_1_2_1_16_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.252.5003.247"},{"key":"e_1_2_1_17_1","doi-asserted-by":"publisher","DOI":"10.1029\/JB095iB06p08339"},{"key":"e_1_2_1_18_1","doi-asserted-by":"publisher","DOI":"10.1086\/110410"},{"key":"e_1_2_1_19_1","doi-asserted-by":"publisher","DOI":"10.1086\/182975"},{"key":"e_1_2_1_20_1","doi-asserted-by":"publisher","DOI":"10.1086\/115602"},{"key":"e_1_2_1_21_1","doi-asserted-by":"publisher","DOI":"10.1086\/115603"},{"key":"e_1_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1086\/108904"}],"container-title":["Journal of Geophysical Research: Planets"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1029%2F92JE01166","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1029\/92JE01166","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,22]],"date-time":"2023-09-22T21:35:32Z","timestamp":1695418532000},"score":1,"resource":{"primary":{"URL":"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/10.1029\/92JE01166"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,8,25]]},"references-count":21,"journal-issue":{"issue":"E8","published-print":{"date-parts":[[1992,8,25]]}},"alternative-id":["10.1029\/92JE01166"],"URL":"https:\/\/doi.org\/10.1029\/92je01166","archive":["Portico"],"relation":{},"ISSN":["0148-0227"],"issn-type":[{"value":"0148-0227","type":"print"}],"subject":[],"published":{"date-parts":[[1992,8,25]]}}}