Satellite Communications Part 11

Tham khảo tài liệu 'satellite communications part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Guidelines for Satellite Tracking 291 aDF - ao 3k2 1 - 502 3k22 7 -11402 39504 5k4 3 - 3602 4904 2afPoi 16a oiPo 4a oiPo nO t - to 25 F _ 3r 4 k4 - 4 aE 8 According to previous cases J 4 is the fourth gravitational zonal harmonic of the Earth 3k 0 3k22 40-1903 5k40 3 - 702 3k20 2 4 V _ 2 4 4 8 4 8 ao po 2ao po 2 ao po Qdf -Qo n 0 t - to 26 27 And Q o is the mean longitude of ascending node at epoch. Sa - B C3 cosao t-to 28 SM - qo -s 4 B ệ4 1 7 cos MDF 3 - 1 7 cos Mo 3 29 Mp - Mdf Sa SM 30 a - DF - Sa - S. d 31 Q - QDF - r nj 2 2 2 C1 t - to 2 32 2 ao po e - eo - B C4 t - to -B C5 sin Mp - sin Mo 33 a - 4 -C1 t-to -D2 t-to -D3 t-to -D4 t-to 34 IL - Mp a Q n 3 C1 t -10 2 D2 2C12 t -10 3 1 3D3 12C1D2 10C13 t -10 4 2 1 o 21 o 43 12 1 o 1 3D4 12C1D3 6D22 30C12D2 15C14 t - to 5 P-yj 1 - e2 n - keỊa 32 35 36 37 where t - to is time since epoch. 292 Satellite Communications In cases where perigee height is less than 220 kilometers the equations for a and IL should be truncated after the C1 term and all terms involving C5 Ỗ and ỖM should be dropped. Add the long-period periodic terms axN e cos L s ecos 2 5 8k2ap2 v 1 e . A3 0sin io ayNL . n2 4k2 ap2 ILT IL ILl ayN e sin ayNL Next step involves solving the Kepler s equation for é by defining U L-Q E i 1 E i A E I U - ayN cos E i axN sin E i - E i A E i ------ ------T------- 7-----r------- 1 ayN sin E i - axN cos E . 1 E 1 U The following equations are used to calculate preliminary quantities needed for short-period periodics. 38 39 40 41 42 43 44 45 46 ecosE axN cos E ayN sin E 47 esinE axN sin E -ayN cos E 48 2 n 2 12 eL axN ayN 49 Pl a 1 - eL2 50 r a 1 - e cos E 51 r ke e sin E 52 r Guidelines for Satellite Tracking 293 a cos u r a sin u r rf k lP-r cos E - axN sin E - ayN 1 u tan ayN e sin E 1 1 - eL 2 axN e sin E 1 V1 - eL2 sin u cos u Ar - - 1-Ớ2 cos2u 2 Pl Au - fc22 7Ớ2 -1 sin2u 3k6 . AQ sin 2u 2 Pl l i 3kw Ai sin io cos 2u 2 Pl Ar -ỈÉỈĨL 1 -ỹ2 sin2u Pl ỵ Arf 1-62 cos2u Pl I 7 -1 1 - w2 53 54 55 56 57 58 59 60 .