File name: sample.descr.txt Author: Paul R. gazis Date: 7-APR-2006 This file contains a description of the contents of sample.bin, a binary file of sample data for demonstration of the 'viewpoints' analysis package, along with a brief description of how that data can be used. This file contains a small subset of the Pioneer 10 data set. The Pioneer 10 and 11 spacecraft, launched in 1972 and 1973, respectively, were the first spacecraft to encounter Jupiter and Saturn, and in 1983, Pioneer 10 became the first man-made object to leave the solar system. The full data Pioneer data set is available from the National Space Science Data Center (NSSDC) http://nssdc.gsfc.nasa.gov/ from their FTP site at ftp://nssdcftp.gsfc.nasa.gov/spacecraft_data/ These data consist of a set of times, trajectory information, and hourly averaged solar wind speed, density, temperatures, and flow angles described below. They encompass the range of helioncentric distances between 1 and 17 AU when Pioneer 10 began to observe quasi-periodic co-rotating inbteraction regions associated with the interaction of low- and high-speed streams in the solar wind. Within these regions, solar wind speed is moderate (of the order 400-500 km/s) while solar wind densoty and temperature are elevated. This is readily apparent if one compares scatter plots of speed, density, and temperature observed in 1972 and early 1973, when the spacecraft was comparatively close to the Sun, with scatter plots at later times and latger distances. NOTE 1: To compare solar wind densities and temperatures observed at different heliocentric distances, it is necessary to account for evolutionary effects as the solar wind is convected outward from the Sun. This is done by scaling the density, N, by heliocentric distance squared, to account for simple radial expansion and by scaling the temperature, T, by R^-0.6 to account for the empirically observed power-law dependance, which is significantly hotter than would be expected for simple adiabatic cooling. NOTE 2: While 'viewpoints' was NOT originally designed to display time series data, it can be used for this purpose. ! File name: sample.txt - Hourly averaged Pioneer 10 solar wind parameters, 1972-1978 ! Field Parameter Comments ! 1 Year - Year of measurement (Spacecraft ephemeris time at Pioneer 10) ! 2 days-1950 - Time of measurement in days since day 1 of 1950 ! 3 R(AU) - Heliocentric distance of spacecraft in AU ! 4 Phi - Heliographic longitude of spacecraft ! 5 Theta - Heliographic latitude of spacecraft ! 6 V(km/s) - Solar wind speed (km/s) ! 7 NR2(#/cc) - Solar wind proton density multipled by R(AU)^2 to account for radial expansion ! 8 TR-.6(K) - Solar wind proton temperature multipled by R(AU)^(-0.6) to account for radial expansion ! 9 E/W - Solar wind E/W flow angle (+ = in the direction of planetary rotation) ! 10 N/S - Solar wind N/S flow angle (+ = north of the ecliptic) ! 11 N(#/cc) - Unmodified solar wind proton density ! 12 T(K) - Unmodified solar wind proton temperature Year days-1950 R_AU Phi Theta V(km/s) NR2(#/cc) TR-.6(K) E/W N/S N(#/cc) T(K) 1973 8401.0000 3.35613 -66.357 -1.558 323.378 9.230828 4512.5 0.871 -1.960 0.819527 9330.9 1973 8401.0417 3.35641 -66.353 -1.558 324.071 9.638469 5078.6 1.611 -2.156 0.855575 10502.0 1973 8401.0833 3.35669 -66.348 -1.558 318.470 11.603700 5170.5 1.131 -2.431 1.029850 10692.6 1973 8401.1250 3.35697 -66.343 -1.558 320.427 18.037112 4589.0 2.875 -3.245 1.600560 9490.5 1973 8401.2083 3.35753 -66.334 -1.557 323.891 17.943892 6167.9 3.389 -4.430 1.591756 12757.1 1973 8401.2500 3.35781 -66.329 -1.557 314.161 21.142727 6616.6 1.903 -4.754 1.875203 13685.7 1973 8401.2917 3.35809 -66.324 -1.557 313.777 21.553091 7349.5 2.516 -4.421 1.911280 15202.4 1973 8401.3333 3.35837 -66.320 -1.557 315.775 20.507291 6770.0 3.275 -3.545 1.818237 14004.4 1973 8401.3750 3.35865 -66.315 -1.557 314.674 16.684952 5431.6 3.303 -3.288 1.479090 11236.4 1973 8401.4167 3.35893 -66.310 -1.557 309.441 17.818612 5698.4 2.730 -3.644 1.579323 11789.0 1973 8401.5000 3.35949 -66.301 -1.557 307.265 13.367473 5107.7 1.608 -2.427 1.184408 10568.0 1973 8401.5417 3.35978 -66.296 -1.557 307.449 11.578219 4689.9 1.086 -2.623 1.025702 9704.0 1973 8401.5833 3.36006 -66.291 -1.556 307.415 11.215317 4828.1 1.104 -2.634 0.993387 9990.5 1973 8401.6250 3.36034 -66.286 -1.556 307.485 11.281679 4760.3 1.111 -2.637 0.999098 9850.7 1973 8401.6667 3.36062 -66.282 -1.556 308.293 12.167288 4800.8 1.723 -2.613 1.077347 9934.9