The first joint experimental results between SURA and CSES

Abstract

In June 2018, for the first time, the SURA heating facility in Russia , together with the in‐orbit China Seismo‐Electromagnetic Satellite (CSES), carried out a series of experiments in emitting high frequency (HF) O‐mode radio waves to disturb the ionosphere. This paper reports data from those experiments, collected onboard CSES, including electric field, in‐situ plasma parameters, and energetic particle flux. Five cases are analyzed, two cases in local daytime and three in local nighttime. We find that the pumping wave frequencies f0 in local daytime were close to the critical frequency of the F2 layer foF2, but no pumping waves were detected by the electric field detector (EFD) on CSES even when the emitted power reached 90 MW, and no obvious plasma disturbances were observed from CSES in those two daytime cases. But on June 16, there existed a spread F phenomena when f0 was lower than foF2 at that local daytime period. During the three cases in local nighttime, the pumping waves were clearly distinguished in the HF‐band electric field at the emitted frequency with the emitted power only 30 MW; the power spectrum density of the electric field was larger by an order of magnitude than the normal background, with the propagating radius exceeding 200 km. Due to the small foF2 over SURA in June at that local nighttime period,f0 in these three cases were significantly higher than foF2, all belonging to under‐dense heating conditions. As for the plasma parameters, only an increase of about 100 K in ion temperature was observed on June 12; in the other two cases (with one orbit without plasma data on June 17), no obvious plasma disturbances were found. This first joint SURA‐CSES experiment illustrates that the present orbit of CSES can cross quite close to the SURA facility, which can insure an effective heating time from SURA so that CSES can observe the perturbations at the topside ionosphere excited by SURA in the near region. The detection of plasma disturbances on June 12 with under‐dense heating mode in local nighttime provides evidence for likely success of future related experiments between CSES and SURA, or with other HF facilities.

Survey on signal processing for GNSS under ionospheric scintillation: Detection, monitoring, and mitigation

“…On a more controversial note, the study of ionospheric scintillation and its countermeasures could be potentially relevant in human‐induced events such as those recently reported in Zhang et al. (2018). In those experiments, the ionosphere was manipulated through the emission of radio‐frequency signals from atmospheric heating facilities, potentially distorting (purposely or not) signals crossing the ionosphere.…”

The Electromagnetic Emissions and Plasma Modulations at Middle Latitudes Related to SURA‐CSES Experiments in 2018

“…In the first report, Zhang et al (2018) have given the preliminary results about the CSES‐SURA experiments in June 2018. CSES observations showed that the HF band electric field indeed recorded the PWs from SURA in three nighttime experiments, but not in two daytime cases, even with higher emitted power in local daytime.…”

“…Initially, this modulation was used to highlight HF signals under investigation against the background of other radiated signals, and then, such signals can be used for ionosphere sounding. Among three experiments in June 2018, the pumping scheme of [+0.9 s, −0.1 s] was employed, but not analyzed in our former paper (Zhang et al, 2018). As mentioned in section 2.1, the first 2,048 data were stored and downloaded to the ground in HF band waveforms of EFD, with a duration time of 0.2048 ms at each observing point in sampling rate 10 MHz.…”

Introduction to special section on the China Seismo-Electromagnetic Satellite and initial results

“…Zhang XM et al () report preliminary results related to those experiments, using CSES data sets. They analyze five cases, two cases observed in local daytime and three cases in local nighttime.…”