# Automatic Detection of Quasi-Periodic Emissions from Satellite Observations by Using DETR Method
## 2 Dataset and Target
### CSES-01 Satellite and Dataset  
Observations of the electromagnetic field are an important means of gaining a comprehensive understanding of the ionospheric QP emission phenomena in near-Earth space. China successfully launched the CSES-01 into a sun-synchronous polar orbit on 2 February 2018 [12], with the scientific objective of monitoring the ionosphere disturbances related to the strong earthquakes in the lithosphere by detecting the electromagnetic field, ionospheric plasma, and other physical phenomena in global space. The satellite has an altitude of 507 km, inclination of 97.4 degrees, a local time of 14:00 at the descending node, and a sun-synchronous circular orbit [3].  
The electromagnetic field observations in this work were detected by three payloads onboard the CSES-01. The background geomagnetic field is measured by the high-precision magnetometer (HPM), which includes two fluxgate sensors [13] and a coupled dark-state magnetometer [14], providing both vector and scalar values of the total geomagnetic field at a frequency range from 0 Hz to 15 Hz. The magnetic field is detected by a tri-axial search coil magnetometer (SCM) in the frequency range from a few Hz to 20 kHz [15]. The sampling rate of the SCM at the ELF frequency (200 Hz to 2.2 kHz) is 10.24 kHz, and the frequency resolution is 2.5 Hz. The spatial electric field in the frequency band from 0 Hz to 3.5 MHz is measured by an electric field detector (EFD) [16]. An EFD measures electric field fluctuations across a wide frequency range of 0 Hz to 3.5 MHz. It is divided into four channels: ULF (0 Hz-16 Hz), ELF (6 Hz-2.2 kHz), VLF (1.8 kHz-20 kHz), and HF (18 kHz-3.5 MHz). Each channel has a different sampling rate, with rates of 125 Hz, 5 kHz, 50 kHz, and 10 MHz, respectively.  
There are two operational modes for payload operation: survey mode and burst mode. The survey mode operates throughout the entire orbit with a downlink of lower-sampling-rate data, whereas the burst mode is triggered exclusively above the global main seismic belts, with a higher-sampling-rate downlink [12].  
[PERSON] et al. cross-calibrated the consistency of HPM, SCM, and EFD in their overlapped detection frequency range and first evaluated the timing system of the satellite. They found a stable discrepancy in the sampling time differences between EFD and SCM, and then proposed a high-precision synchronization method for the ELF band [17]. [PERSON] et al. confirmed the stability of EFD and SCM after analyzing the sampling time difference in the VLF band between EFD and SCM based on three years of operation and put forward a precise synchronization method for the VLF burst-mode waveform data [18]. [PERSON] et al. validated the wave propagation parameters for the same types of waves based on the electromagnetic field observations from the CSES-01 and DEMETER and confirmed the good performance of EFD and SCM onboard the CSES-01 [19]. [PERSON] et al. validated the HPM data by comparing the Swarm and CHAOS model and ground observatories, and the potential artificial disturbances from the platform and payloads were labeled as data quality flags in the standard Level 2 scientific data [20]. Further, [PERSON] et al. rechecked each year's HPM data, improved the data quality by removing seasonal effects, prolonged the updating period of all calibration parameters from daily to 10 days, and optimized the routine HPM data processing efficiency [21].