A5007968052- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Earthquake Detection and Analysis
- GNSS positioning and interference
- Astro and Planetary Science
- Advanced Frequency and Time Standards
Wuhan University
2011-2023
GFZ Helmholtz Centre for Geosciences
2008
The CHAMP satellite continues to provide highly accurate magnetic field measurements from decreasing orbital altitudes (<350 km) at solar minimum conditions. Using the latest 4 years (2004–2007) of readings fluxgate magnetometer, including an improved scalar data product, we have estimated lithospheric spherical harmonic degree 120, corresponding 333 km wavelength resolution. were found be sensitive crustal variations up 150 (down 266 wavelength), but a clean separation signal ionospheric...
Abstract In this study, we perform the first comprehensive comparison of ion density (Ni) in topside ionosphere measured by Langmuir probe (LP) and faceplate (FP) thermal imager on board Swarm satellites. Our results show a systematic difference between LP FP derived Ni values, shows prominent dependences solar flux, local time, season. Although both datasets generally good linear regression with electron (Ne) measurements from incoherent scatter radar (ISR) located at Jicamarca, an...
Abstract Recent studies revealed that the long-lasting daytime ionospheric enhancements of Total Electron Content (TEC) were sometimes observed in Asian sector during recovery phase geomagnetic storms (e.g., Lei (J Geophys Res Space Phys 123: 3217–3232, 2018), Li 125: e2020JA028238, 2020). However, they focused only on dayside ionosphere, and no dedicated have been performed to investigate nighttime behavior such kinds storm phases. In this study, we two happened 7–8 September 2017 25–26...
Abstract Transient signal loss of the global positioning system (GPS) has been frequently observed by receivers on board European Space Agency's Swarm mission when satellites encounter ionospheric plasma irregularities. In this study we provided first comparison GPS amplitude degradations from low Earth orbiting at different altitudes. Intense carrier phase variations but almost no fades (less than 2 dB Hz) are spaceborne receiver lies right inside irregularities, like case for and CHAMP...
In this study, we focus on plasma patches with very dense in the southern hemisphere during main phase of 2015 St. Patrick’s Day storm. With situ electron densities exceeding 1.5 × 10 12 m −3 at 450–500 km altitude, cause strong signal outages global positioning system (GPS) receivers board Swarm satellites. By using field-aligned currents derived from magnetic measurements, determined whether satellites fly inside auroral oval or not. Different influences spaceborne GPS receiver are seen...
Abstract Based on Swarm satellite data from 2015 through 2018, we present the mean characteristics of magnetic field fluctuations at midlatitudes and low latitudes. It is first comprehensive study focusing small‐scale variations (<10 km). Events are observed about 35% orbits. The highest occurrence rates detected after sunset, in East Asian/Australian sector, during months around June solstice. Low found latitudes (below ±10° quasi‐dipole latitude), region South Atlantic Anomaly, equinox...
The 8 years of continuous CHAMP operation allow us to investigate the long-term behaviours vector magnetometer on board satellite.For processing FGM data primarily 9 instrument parameters are needed (3 offsets, 3 scale factors, misalignment angles).These determined in pre-flight calibration and routinely in-flight scalar calibration.A review temporal evolution shows that factors exhibit a clear change with time.This variation sensitivity can well be described by logarithmic function.The...
Different indices have been used to reflect, or monitor the ionospheric scintillation, e.g. detrended carrier phase, σ φ , S 4 rate of change vertical total electron content index ( v ROTI), as well ionosphere‐free linear combination (IFLC) two phases. However, few studies performed investigate refractive and diffractive contributions these indices, especially during geomagnetic storms. In this study, we analyze high-resolution (50 Hz) phase amplitude measurements from four high-latitude...
Abstract Using 6 years collecting of electron density ( Ne ) data from the Swarm A satellite, this study portrays comprehensive maps occurrence medium‐scale traveling ionospheric disturbance (MSTID) at middle latitudes, which is characterized by in situ absolute fluctuations above a certain threshold. Two interesting spatial preferences on MSTID as well their dependence local time and solar cycle are captured, that is, (1) regional preference near Weddell Sea Anomaly (WSA) to its west during...
Abstract. CHAMP has so far been the most successful magnetic field mission. For achieving that, special effort had to be invested in building a magnetically clean spacecraft. The moment of spacecraft is about 1 Am2. In this article we introduce new method that allows determination during mission from average current strength magneto-torquers. order achieve precise vector data, readings fluxgate magnetometer are routinely calibrated against absolute Overhauser measurements. A reanalysis all...
The CHAMP (CHAllenging Minisatellite Payload) mission ended after more than ten years in space on 19 September 2010. For achieving a high measurement accuracy of the magnetometers CHAMP, detailed analyses spacecraft magnetic characteristics orbit are required. A decade continuous magnetometer and housekeeping data good basis for evaluating some effects variable fields ambient field determination. It was found that perturbations FGM (FluxGate vector Magnetometer) or OVM (OVerhauser scalar...
In this study, we provide the first detailed analysis of variations in spacecraft potential (<italic>V</italic><sub>s</sub>) three Swarm satellites, which are flying at about 400–500 km. Unlike previous studies that have investigated extreme charging events, usually with potentials as negative −100 V, study is focused on <italic>V</italic><sub>s</sub> readings, fall within a few volts. The observations show low Earth orbital (LEO) altitudes charged only slightly negatively, varying between...
利用Swarm卫星2015年1月1日至2019年12月31日的50Hz高频磁场数据，根据阈值判断垂直于主磁场方向的扰动，对磁纬45°N-45°S之间的小尺度电离层行扰事件进行探测.为避免混淆而产生的干扰，可以根据阈值判断平行于主磁场方向是否发生扰动，从而排除典型的赤道等离子体泡事件.但对于较弱的赤道等离子体泡事件，扰动阈值判断无效.为避免弱赤道等离子体泡事件的污染，根据小尺度电离层行扰事件和赤道等离子体泡事件在不同参数空间中的密度分布差异，利用基于密度的聚类算法将赤道等离子体泡事件进一步甄别提取.结果表明，聚类算法能够有效地将赤道等离子体泡事件从小尺度电离层行扰事件中甄选出来，并使小尺度电离层行扰事件聚类与赤道等离子体泡事件聚类形成清晰的边界.由聚类算法导出的弱赤道等离子体泡事件主要分布在磁纬15°N-15°S，地理经度20°-60°W，月份10至3月之间，并且在20:00MLT-24:00MLT存在高发生率，同时依赖于太阳活动，这也验证了前人的相关研究结果.
The Gravity Recovery and Climate Experiment (GRACE) its follow-on mission GRACE-FO are gravity satellites jointly developed by the National Aeronautics Space Administration (NASA) German Aerospace Center (DLR), which composed of two satellites. Such tandem satellite missions provide us with a good opportunity to evaluate ionospheric total electron content (TEC) derived from their onboard global positioning system (GPS) receivers. In addition, K-band ranging (KBR) between provides also...
&lt;div&gt;Based on Swarm satellite data from 2015 through 2018, we present the mean characteristics of&lt;/div&gt;&lt;div&gt;magnetic fifield flfluctuations at midlatitudes and low latitudes. It is fifirst comprehensive study focusing on&lt;/div&gt;&lt;div&gt;small&amp;#8208;scale variations (&lt;10 km). Events are observed about 35% of orbits. The highest occurrence&lt;/div&gt;&lt;div&gt;rates detected after sunset, in East...