17:15 〜 18:45
[PEM15-P03] Horizontal structures of F layer and sporadic E-layer observed by the sounding rocket S-520-32
キーワード：スポラディックE、トモグラフィ、Dual-Band Beacon
Sporadic-E (Es) layers are thin and dense layers appearing from 90 to 120 km and have been studied over six decades. Previous studies presented that the horizontal structure of the Es layer is likely to play an essential role in the generation of medium-scale traveling ionospheric disturbances (MSTIDs) due to E-F coupling via the Earth’s magnetic field lines.
The sounding rocket S-520-32, which aimed to observe irregularities associated with the Es layer and MSTIDs, was launched from Uchinoura Space Center (USC), JAXA (31.25 deg. N, 131.08 deg. E) at 23:20:00 JST (UT+9) on 11 August 2022. It transmitted the dual-band beacon signals (150 and 400 MHz) and received GNSS signals to separately observe the total electron content (TEC) in the E and F regions during the flight. The rocket flew between the E and F-layers and reached an altitude of 270 km. It splashed into the sea around 23:28:43. During the rocket flight, the MSTIDs were seen in the TEC map derived from the GNSS receiver network around the rocket trajectory. The ionosonde in Yamagawa, Kagoshima, 44 km away from USC, detected the Es layer, and the foEs and altitude of the Es layer were approximately 4.2 MHz and 116 km.
We installed the beacon receivers at USC, Tarumizu (TRM) (31.49 deg. N, 130.70 deg. E), Kirishima (KRS) (31.73 deg. N 130.73 deg. E), and Satsumasendai (SND) (31.83 deg. N, 130.34 deg. E). These four sites almost aligned with the backward extension of the line of rocket trajectory. We calculated the Total Electron Content (TEC) by the phase doppler of dual-band beacon signals and performed the tomography analysis with the TEC values observed at four sites. The Es layer was distributed around 100 km distance from the USC, but from 100 to 220 km, there was no single peak of electron density. The Es layer was found again around 220 to 300 km from the USC, but the altitude was lower by about 4 km, and the peak density was smaller by 1-4x1010 m-3 than the Es layer around 100 km from the USC.
The GNSS receiver received GPS, QZSS, Galileo, and BeiDou satellite signals. The deviation components of TEC (dTEC) was derived from the time series of phase doppler of the GNSS signals and compared with the horizontal structure of the Es layer which is connected by the Earth’s magnetic field line. The increase in dTEC can be seen above the Es layer, while dTEC decreased in the F region, corresponding to areas where the Es layer was not observed. Those characteristics suggested that the horizontal structure between F and Es layer seemed to show good agreement. In this presentation, we will show the observation results as well as the comparison of it with ionosonde and onboard instruments. Furthermore, we will compare the horizontal structure of the Es layer and the F-region structure to discuss the E-F coupling process.
The sounding rocket S-520-32, which aimed to observe irregularities associated with the Es layer and MSTIDs, was launched from Uchinoura Space Center (USC), JAXA (31.25 deg. N, 131.08 deg. E) at 23:20:00 JST (UT+9) on 11 August 2022. It transmitted the dual-band beacon signals (150 and 400 MHz) and received GNSS signals to separately observe the total electron content (TEC) in the E and F regions during the flight. The rocket flew between the E and F-layers and reached an altitude of 270 km. It splashed into the sea around 23:28:43. During the rocket flight, the MSTIDs were seen in the TEC map derived from the GNSS receiver network around the rocket trajectory. The ionosonde in Yamagawa, Kagoshima, 44 km away from USC, detected the Es layer, and the foEs and altitude of the Es layer were approximately 4.2 MHz and 116 km.
We installed the beacon receivers at USC, Tarumizu (TRM) (31.49 deg. N, 130.70 deg. E), Kirishima (KRS) (31.73 deg. N 130.73 deg. E), and Satsumasendai (SND) (31.83 deg. N, 130.34 deg. E). These four sites almost aligned with the backward extension of the line of rocket trajectory. We calculated the Total Electron Content (TEC) by the phase doppler of dual-band beacon signals and performed the tomography analysis with the TEC values observed at four sites. The Es layer was distributed around 100 km distance from the USC, but from 100 to 220 km, there was no single peak of electron density. The Es layer was found again around 220 to 300 km from the USC, but the altitude was lower by about 4 km, and the peak density was smaller by 1-4x1010 m-3 than the Es layer around 100 km from the USC.
The GNSS receiver received GPS, QZSS, Galileo, and BeiDou satellite signals. The deviation components of TEC (dTEC) was derived from the time series of phase doppler of the GNSS signals and compared with the horizontal structure of the Es layer which is connected by the Earth’s magnetic field line. The increase in dTEC can be seen above the Es layer, while dTEC decreased in the F region, corresponding to areas where the Es layer was not observed. Those characteristics suggested that the horizontal structure between F and Es layer seemed to show good agreement. In this presentation, we will show the observation results as well as the comparison of it with ionosonde and onboard instruments. Furthermore, we will compare the horizontal structure of the Es layer and the F-region structure to discuss the E-F coupling process.