## 2 Satellite and Payloads
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Detection Objectives** & **Payloads** & **Parameters** \\ \hline \multirow{6}{*}{The geomagnetic field} & \multirow{6}{*}{High-Precision Magnetometer (HPM)} & Including two tri-axial fluxgate magnetometers (FAMs) and one coupled dark-state magnetometer (CDSM) & \\  & & Detection band: DC to 15 Hz & \\ \cline{1-1}  & & The vector and scalar values & \\ \hline \multirow{6}{*}{The electromagnetic field} & \multirow{6}{*}{Search-Coil Magnetometer (SCM)} & The waveform or power spectral density values in the three frequency bands: ULF: 10 Hz–200 Hz, sampling rate 1024 Hz & \\  & & ELF: 200 Hz–2200 Hz, sampling rate 10.24 kHz, & \\  & & VLF: 1.8 kHz–20 kHz, sampling rate 50 kHz & \\ \cline{1-1}  & & The waveform or power spectral density values in the four frequency bands: ULF: DC–16 Hz, sampling rate 128 Hz, & \\ \cline{1-1}  & Electric field detector (EFD) & ELF: 6 Hz–2.2 kHz, sampling rate 5 kHz & \\ \cline{1-1}  & & VLF: 1.8 kHz–20 kHz, sampling rate 51.2 kHz & \\ \cline{1-1}  & & HF: 18 kHz–3.5 MHz, sampling rate 10 MHz. & \\ \hline \multirow{6}{*}{The in situ ionospheric parameters} & \multirow{2}{*}{Plasma analyzer package (PAP)} & Inon density, ion temperature, ion contents (H\({}_{+}\), O\({}_{+}\), He\({}_{+}\)) & \\ \cline{1-1}  & & Ion drift velocity (Vx, Vy, Vz) & \\ \cline{1-1}  & Langmuir probe (LAP) & Electron density/temperature, the plasma/the satellite floating potential & \\ \hline \multirow{6}{*}{The profile ionospheric parameters} & GNSS Occultation Receiver (GOR) & TEC, Ne profile, the profile of air temperature and pressure, HmF2, NmF2 \\ \cline{2-2}  & & Three bands: 50/400/1066 MHz, & \\ \cline{1-1}  & Tri-Band Beacon (TBB) & Physical values: relative TEC, Ne Profile, ionospheric scintillation index, and ionosphere tomography & \\ \cline{1-1}  & & HEPP-L: Electron: 0.1–3 MeV, Proton: 2-20 MeV & \\ \cline{1-1}  & Energetic particle detector (HEPP), including three detectors, HEPP-H, HEPP-L, and HEPP-X. & 2-20 MeV & \\ \cline{1-1}  & & HEPP-X: Solar X-ray: 0.9–35 keV & \\ \cline{1-1}  & & Proton flux: 30–100 MeV & \\ \cline{1-1}  & & Electron flux: 30–200 MeV & \\ \hline \end{tabular}
\end{table} 
Table 1: The scientific payloads onboard CSES. bands continuously along the whole orbit trajectory in the survey mode, allowing us to examine the wave propagation parameters at any time of interest. The waveform data of VLF/HF is downlinked only during burst mode due to the limitation of telemetry capability. For the ionospheric plasma parameter detection, a Langmuir probe (LAP) and a set of plasma analyzer packages (PAPs) [24] provide the in situ ionospheric plasma parameters (electron and ion); a GNSS occultation receiver (GOR), and a tri-band beacon (TBB) transmitter together with about 15 ground-based receivers [25] provide the ionospheric profile parameters, such as the TEC (total electron content), electron density profile, and ionospheric scintillation index. For the energetic particles, there are a set of high-energy-particle packages (HEPPs) [26], and a high-energy-particle detector (HEPD) [27] provided by the Italian Space Agency, jointly detecting the energetic particles in an energy level range from ~0.1 MeV to 200 MeV. The first six-month in-orbit commission tests demonstrate that the scientific instruments generally perform well, except for the PAP, EFD, and TBB, which have some defects in different aspects. PAP was contaminated after four months in orbit, leading to lower absolute values than expected; further evaluation suggests that the relative values of ion densities can be used in scientific applications. The EFD is heavily interfered with by the satellite-internal communication over the equatorial region and has a high noise level in the HF band. The middle frequency band (400 MHz) of the TBB (needs the ground-based receivers to realize the coherent beacon system) malfunctioned after launch, so the data quality of the TBB is still under evaluation.