CAJ | 학술논문

通过分析SELENE的两颗小卫星Rstar和Vstar的同波束VLBI数据，发现两卫星间差分时延率中由中性大气和电离层引起的长周期变化已被去除，且在小角距时，短周期变化也能绝大部分被去除。但角距离越大，去除部分越小。通过将2008年一年中8个台站组成的所有基线的相关相位拟合残差数据分别平滑积分30 s与60 s 后，再通过5点直线拟合求得时延率，得出单卫星时延率随机误差分别约为0.32 ps/s RMS与0.20 ps/s RMS，而差分时延率随机误差分别为0.19 ps/s～0.32 ps/s RMS与0.09 ps/s～0.17 ps/s RMS。单卫星的时延率随机误差在秋季最大，春季最小，而差分时延率的随机误差在全年基本稳定。
통과분석SELENE적량과소위성Rstar화Vstar적동파속VLBI수거，발현량위성간차분시연솔중유중성대기화전리층인기적장주기변화이피거제，차재소각거시，단주기변화야능절대부분피거제。단각거리월대，거제부분월소。통과장2008년일년중8개태참조성적소유기선적상관상위의합잔차수거분별평활적분30 s여60 s 후，재통과5점직선의합구득시연솔，득출단위성시연솔수궤오차분별약위0.32 ps/s RMS여0.20 ps/s RMS，이차분시연솔수궤오차분별위0.19 ps/s～0.32 ps/s RMS여0.09 ps/s～0.17 ps/s RMS。단위성적시연솔수궤오차재추계최대，춘계최소，이차분시연솔적수궤오차재전년기본은정。
As shown by our analyses difference delay rates from SELENE same-beam VLBI data are almost not influenced by long-term effects on radio signals from the ionosphere and neutral atmosphere .The short-term effects on radio signals from the atmosphere can be mostly eliminated if the separation angle between two satellites is small (<0.1°), but becomes more appreciable and more difficult to be eliminated as the separation angle increases .We further integrate the residuals of correlation phases for a set of data after fits to their systematic trends are subtracted .The data were observed with all baselines of 8 VLBI stations through 2008.Some integrations are over time intervals of 60s or 30s, and each integration generates a data point for detailed analyses .We apply linear fits to every 5 data points to find delay rates and difference delay rates . Statistics of these show that rms values of random errors of delay rates of two satellites are about 0.20 ps/s and 0.32 ps/s, respectively .Our statistics also show that rms values of random errors of difference delay rates of two satellites are 0.09ps/s to 0.17ps/s and 0.19ps/s to 0.32ps/s, respectively.Random errors of delay rates are statistically small in the spring and larger in the autumn , but those of difference delay rates are stable throughout the year .