Drift shell tracing code Chris Paranicas and Andrew Cheng JHU/Applied Physics Laboratory, 8/96 For Galileo ephemeris, we appreciate the help of Nat Bachman, Robin Gary, Tom Garrard, and Neil Murphy. I. Output. Output file contains time, position of Galileo (r, lat, east long), L shell calculated, K used to calculate L, B of s/c calculated with model field, and B min on field line calculated with model field. We scale lengths to 1 RJ = 71492 km. II. Calculated Parameters. 1) The L value of the s/c in the particular field model for charged particles with constant K. L is calculated following the method outlined in JGR, 99, 19433, 1994 by Paranicas and Cheng, where, L=2*pi*DM/abs(phi). For any field model, this formula requires a scaling, DM, which we take to be a nominal dipole moment. Phi is the third adiabatic invariant equal to the magnetic flux enclosed by the particle drift shell. We do not include a current sheet at the moment. 2) The value of the second adiabatic invariant, K, in the units sqrt(G)-RJ. This is the K that was used to trace the drift shell and is assumed to be constant on the drift shell. 3) B at the location of the s/c in Gauss as calculated by the particular magnetic field model. 4) The minimum-B (in G) on the field line the spacecraft occupies in the particular magnetic field model. III. Testing drift shell tracing code. To test the code, we calculate the following: LDC = L(OTD model) = L value using tracing code and an offset, tilted dipole model for the field. LDF = L(Dipole formula) = L value using a formula relating position to L shell in an offset, tilted dipole field. For 80 equally-spaced-in-time locations of Galileo between Dec 7, 1995 14:00 - Dec, 8, 1995 05:00, and Bm=0.25 G, we found, Max (LDC/LDF) = 1.0015 and for these 80 points, (1/80) * sum (LDC - LDF)^2 = 3.4e-04 _____________________________________________________________________________ Produced on 4-8-97 Output of tracing code. We calculate the quantities: K, L, B of s/c, and Bmin on s/c field line, using: GSFC O6 model with normalization for L, DM = 4.28 G-RJ^3 This file contains: ihr,imn,isc,r(RJ),lat(deg),east long(deg),L K(sqrt(G)-RJ),B s/c in G, B min in G Time is measured from Sep 6, 1996 00:00:00 Position is Jovian geographic coordinates calculated from the JPL SPICE kernel with input files: gll00007.tpc, gll00007.tls, and s960728a.bsp Other inputs to tracing code are: ipl,sn,rf,dh1,deps,dhs,depss,bm 1 2 1.0 1.00000E-02 1.00000E-03 3.00000E-02 .1 1.00000E-02 Questions contact Chris Paranicas, APL 301-953-5000 x8652 12 0 0 17.69501 -.892143 81.30233 17.65646 2.59226 7.66404E-04 7.65981E-04 12 10 0 17.62926 -.870546 75.54673 17.59793 2.57631 7.73729E-04 7.73671E-04 12 20 0 17.56358 -.848764 69.79329 17.54237 2.56145 7.81796E-04 7.80490E-04 12 30 0 17.49794 -.826796 64.04205 17.49416 2.55041 7.90621E-04 7.86452E-04 12 40 0 17.43237 -.80464 58.29301 17.46544 2.5402 8.00199E-04 7.91613E-04 12 50 0 17.36685 -.782295 52.5462 17.43041 2.53132 8.10506E-04 7.96052E-04 13 0 0 17.3014 -.759759 46.80166 17.39908 2.52387 8.21503E-04 7.99892E-04 13 10 0 17.23601 -.737029 41.05939 17.37555 2.51734 8.33134E-04 8.03275E-04 13 20 0 17.17069 -.714106 35.31943 17.35832 2.51141 8.45330E-04 8.06367E-04 13 30 0 17.10544 -.690986 29.5818 17.34061 2.50564 8.58014E-04 8.09352E-04 13 40 0 17.04026 -.667669 23.84652 17.31539 2.49983 8.71098E-04 8.12424E-04 13 50 0 16.97515 -.644152 18.11362 17.29041 2.49347 8.84493E-04 8.15789E-04 14 0 0 16.91011 -.620434 12.38312 17.26457 2.4863 8.98106E-04 8.19636E-04 14 10 0 16.84516 -.596513 6.65506 17.23353 2.47784 9.11842E-04 8.24176E-04 14 20 0 16.78028 -.572388 .9294412 17.19221 2.46775 9.25611E-04 8.29596E-04 14 30 0 16.71549 -.548057 355.2062 17.15171 2.45584 9.39325E-04 8.36079E-04 14 40 0 16.65079 -.523518 349.4856 17.10406 2.44199 9.52905E-04 8.43792E-04 14 50 0 16.58617 -.49877 343.7675 17.04 2.42563 9.66279E-04 8.52875E-04 15 0 0 16.52165 -.473811 338.052 16.96968 2.40704 9.79387E-04 8.63450E-04 15 10 0 16.45721 -.448639 332.339 16.89006 2.38597 9.92180E-04 8.75613E-04 15 20 0 16.39288 -.423253 326.6287 16.8041 2.36228 1.00463E-03 8.89417E-04 15 30 0 16.32864 -.397651 320.9209 16.70781 2.33671 1.01672E-03 9.04882E-04 15 40 0 16.2645 -.371832 315.2159 16.60278 2.30887 1.02847E-03 9.21983E-04 15 50 0 16.20047 -.345793 309.5135 16.49223 2.27917 1.03989E-03 9.40650E-04 16 0 0 16.13654 -.319534 303.8139 16.38093 2.24849 1.05105E-03 9.60737E-04 16 10 0 16.07272 -.293052 298.117 16.25895 2.21659 1.06203E-03 9.82071E-04 16 20 0 16.00901 -.266346 292.4229 16.13942 2.18411 1.07292E-03 1.00440E-03 16 30 0 15.94542 -.239414 286.7316 16.01813 2.15165 1.08387E-03 1.02742E-03 16 40 0 15.88194 -.212254 281.0432 15.90106 2.11946 1.09501E-03 1.05077E-03 16 50 0 15.81858 -.184866 275.3576 15.78249 2.08862 1.10652E-03 1.07406E-03 17 0 0 15.75534 -.157247 269.6748 15.67307 2.05857 1.11855E-03 1.09687E-03 17 10 0 15.69222 -.129395 263.9951 15.57468 2.03174 1.13129E-03 1.11877E-03 17 20 0 15.62922 -.10131 258.3183 15.47534 2.00577 1.14488E-03 1.13934E-03 17 30 0 15.56634 -7.29881E-02 252.6445 15.40127 1.98434 1.15947E-03 1.15823E-03 17 40 0 15.50358 -4.44293E-02 246.9737 15.32806 1.96463 1.17516E-03 1.17513E-03 17 50 0 15.44093 -1.56320E-02 241.3059 15.26301 1.94779 1.19199E-03 1.18983E-03 18 0 0 15.3784 1.34046E-02 235.6413 15.20912 1.93391 1.20999E-03 1.20224E-03 18 10 0 15.31595 4.26792E-02 229.9798 15.16389 1.92214 1.22911E-03 1.21237E-03 18 20 0 15.25358 7.21856E-02 224.3216 15.13144 1.91372 1.24924E-03 1.22039E-03 18 30 0 15.19123 .1019021 218.6666 15.1064 1.907 1.27024E-03 1.22656E-03 18 40 0 15.12878 .1317456 213.0149 15.08432 1.90097 1.29194E-03 1.23129E-03 18 50 0 15.06592 .1612668 207.367 15.07154 1.89739 1.31419E-03 1.23512E-03 19 0 0 15.00164 .1860413 201.7227 15.05795 1.89355 1.33696E-03 1.23888E-03 19 10 0 14.93729 .1956156 196.0792 15.04228 1.88917 1.35953E-03 1.24298E-03 19 20 0 14.87438 .200404 190.4374 15.02506 1.8845 1.38127E-03 1.24743E-03 19 30 0 14.81216 .2044622 184.7984 15.00328 1.8787 1.40217E-03 1.25285E-03 19 40 0 14.75037 .2083147 179.1625 14.97607 1.87172 1.42209E-03 1.25971E-03 19 50 0 14.6889 .2120899 173.5299 14.94141 1.86268 1.44088E-03 1.26842E-03 20 0 0 14.62771 .2158339 167.9007 14.89799 1.85146 1.45844E-03 1.27924E-03 20 10 0 14.56678 .2195671 162.2749 14.84673 1.83812 1.47469E-03 1.29238E-03 20 20 0 14.50609 .2233 156.6526 14.78854 1.82267 1.48963E-03 1.30790E-03 20 30 0 14.44564 .2270385 151.0338 14.72173 1.80499 1.50330E-03 1.32579E-03 20 40 0 14.38543 .2307873 145.4186 14.64837 1.78552 1.51580E-03 1.34593E-03 20 50 0 14.32546 .2345473 139.8069 14.56799 1.76421 1.52727E-03 1.36813E-03 21 0 0 14.26572 .2383197 134.1988 14.48542 1.74234 1.53789E-03 1.39210E-03 21 10 0 14.20623 .2421054 128.5944 14.39375 1.71817 1.54789E-03 1.41752E-03 21 20 0 14.14698 .2459049 122.9937 14.31013 1.69602 1.55752E-03 1.44400E-03 21 30 0 14.08798 .2497186 117.3967 14.22196 1.67294 1.56702E-03 1.47113E-03 21 40 0 14.02922 .2535464 111.8034 14.13466 1.65003 1.57666E-03 1.49849E-03 21 50 0 13.97072 .2573884 106.214 14.0508 1.62789 1.58670E-03 1.52569E-03 22 0 0 13.91248 .2612445 100.6283 13.97038 1.60663 1.59739E-03 1.55233E-03 22 10 0 13.85451 .2651145 95.04653 13.89316 1.58648 1.60896E-03 1.57807E-03 22 20 0 13.79681 .2689981 89.46859 13.82176 1.56766 1.62161E-03 1.60262E-03 22 30 0 13.73938 .2728951 83.89456 13.7557 1.55041 1.63550E-03 1.62576E-03 22 40 0 13.68223 .2768051 78.32448 13.69529 1.5346 1.65078E-03 1.64731E-03 22 50 0 13.62537 .2807277 72.75836 13.64054 1.5202 1.66754E-03 1.66719E-03 23 0 0 13.56881 .2846625 67.19625 13.59016 1.50705 1.68583E-03 1.68537E-03 23 10 0 13.51254 .2886089 61.63816 13.54631 1.49559 1.70569E-03 1.70189E-03 23 20 0 13.45658 .2925665 56.08413 13.50658 1.48525 1.72709E-03 1.71688E-03 23 30 0 13.40093 .2965357 50.53419 13.47033 1.47571 1.74999E-03 1.73049E-03 23 40 0 13.3456 .3005156 44.98836 13.43841 1.46737 1.77432E-03 1.74295E-03 23 50 0 13.29059 .3045051 39.44667 13.40852 1.45958 1.79998E-03 1.75452E-03 24 0 0 13.23591 .3085034 33.90916 13.38131 1.45231 1.82684E-03 1.76549E-03 24 10 0 13.18158 .3125098 28.37584 13.35408 1.44525 1.85476E-03 1.77620E-03 24 20 0 13.12759 .3165237 22.84674 13.32651 1.43798 1.88359E-03 1.78698E-03 24 30 0 13.07394 .3205443 17.32188 13.2985 1.43078 1.91318E-03 1.79819E-03 24 40 0 13.02066 .3245708 11.8013 13.26774 1.42286 1.94335E-03 1.81018E-03 24 50 0 12.96775 .3286025 6.28502 13.23291 1.41359 1.97393E-03 1.82332E-03 25 0 0 12.91521 .3326385 .7730495 13.20359 1.40604 2.00477E-03 1.83793E-03 25 10 0 12.86305 .3366779 355.2654 13.16485 1.39604 2.03569E-03 1.85435E-03 25 20 0 12.81128 .3407199 349.7621 13.12258 1.38486 2.06655E-03 1.87290E-03 25 30 0 12.75991 .3447634 344.2632 13.07378 1.37214 2.09720E-03 1.89383E-03 25 40 0 12.70894 .3488076 338.7687 13.01993 1.35813 2.12752E-03 1.91740E-03 25 50 0 12.65838 .3528514 333.2786 12.96178 1.343 2.15738E-03 1.94381E-03 26 0 0 12.60825 .3568938 327.793 12.89695 1.32625 2.18670E-03 1.97319E-03 26 10 0 12.55854 .3609337 322.3118 12.82472 1.30744 2.21543E-03 2.00563E-03 26 20 0 12.50927 .36497 316.835 12.74817 1.28866 2.24351E-03 2.04114E-03 26 30 0 12.46044 .3690015 311.3628 12.67382 1.26823 2.27096E-03 2.07965E-03 26 40 0 12.41207 .3730272 305.895 12.59116 1.24676 2.29782E-03 2.12094E-03 26 50 0 12.36416 .3770457 300.4317 12.50532 1.22456 2.32417E-03 2.16477E-03 27 0 0 12.31672 .3810558 294.9729 12.41813 1.20206 2.35015E-03 2.21072E-03