Equatorial bubbles as observed with GPS measurements over Pune, India
Equatorial bubbles as observed with GPS measurements over Pune, India
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印度浦那上空 GPS 测量观测到的赤道气泡
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发表时间：
2006
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通讯作者：
S. Ananthakrishnan
中科院分区：
文献类型：
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作者：
A. DasGupta;A. Paul;S. Ray;A. Das;S. Ananthakrishnan
自2003年4月以来，在印度浦那(地理纬度19.1°N，东经74.05°；倾角24°N)使用双频GPS接收器连续记录了电离层总电子含量(TEC)和闪烁，该地点位于磁赤道和赤道异常的北脊之间。当在GPS L1载波电平上观察到严重的幅度闪烁时，TEC经常显示咬合现象。由于不规则云和卫星之间的相对速度的存在，咬合的表观持续时间可能不同于通过地球静止链路观察到的真正的东西持续时间。GPS卫星的轨道在观测气泡特性方面起着重要作用。得到了2004年2月至4月春分期间气泡的振幅和持续时间的分布。中位数分别为9个TEC单位(1Tecu=1016el/m2)和3.3min。在GPSL1频段，TEC损耗中值对应的距离误差为1.4m，第95个百分位数对应的距离误差为4.5m。气泡东西壁和损耗边缘的不对称性导致了高的距离误差率∼30 cm/min。
Ionospheric total electron content (TEC) and scintillations have been recorded continuously since April 2003 using a dual‐frequency GPS receiver at Pune, India (geographic latitude 19.1°N, longitude 74.05°E; 24°N dip), situated in between the magnetic equator and the northern crest of the equatorial anomaly. The TEC often shows bite‐outs when severe amplitude scintillations are observed on the GPS L1 carrier level. The apparent duration of the bite‐outs may be different from the true east‐west duration, as observed with geostationary links, because of the presence of a relative velocity between the irregularity cloud and the satellite. The trajectory of a GPS satellite plays an important role in observing the bubble characteristics. The distributions of amplitude and duration of the bubbles have been obtained during the equinoctial months February through April of 2004. The median values are found to be 9 TEC units (1 TECU = 1016 el/m2) and 3.3 min, respectively. The range error at GPS L1 frequency corresponding to the median TEC depletion is 1.4 m, while that corresponding to the 95th percentile value is 4.5 m. An asymmetry in the east‐west walls of the bubble and sharp edges of the depletions resulting in high range error rates ∼30 cm/min has been noted.