Many electromagnetic emissions related to earthquakes have been observed by using space-based monitoring systems in the past decades. Such systems can operate together with ground-based monitoring networks to improve the capability to detect abnormal information related to earthquakes. The first French-developed satellite

known as Detection of Electro-Magnetic Emission Transmitted from Earthquake Regions (DEMETER)

is used for detecting ionospheric perturbations associated with earthquakes and volcanic eruptions. DEMETER has produced significant results

but the mission ended in 2010. However

the China Seismo-Electromagnetic Satellite (CSES) project began in 2013

and CSES will be launched in early 2018. CSES is proposed to be the first experimental satellite for earthquake-related electromagnetic emission monitoring from the ionosphere. This satellite is the first space observation platform within the 3D earthquake observation system in China. The objectives of CSES are as follows: (1) obtain worldwide data on space environment of the electromagnetic field

ionospheric plasma

and energetic particles; (2) monitor ionospheric perturbations in real-time when the satellite passes over Chinese territories and their adjacent area; and (3) investigate ionospheric perturbations that may be associated with earthquake activity

especially destructive phenomena. Eight scientific payloads

including search coil magnetometer

high precision magnetometer

electric field detector

GNSS occultation receiver

plasma analyzer package

Langmuir probe

high energy particle analyzer

and tri-band beacon

will be on board CSES to address the aforementioned objectives. All the payloads are used for monitoring the electromagnetic field

its disturbances

and the ionosphere environment. The payloads are also used to obtain the changing information of ionospheric structure below the satellite altitude. The detecting elements include electromagnetic field

plasma wave

electron density

electron temperature

ion temperature

ion composition

ion velocity distribution

and ion drift velocity. The CSES will provide an approach to studying the electromagnetic disturbances related to earthquakes

recognizing the regularity and mechanism of ionospheric disturbance

and studying atmosphere-ionosphere-lithosphere interactions. The data process method of CSES is a completely new research field for Chinese researchers

and the method has been developed in recent years. In this paper

we introduced the data catalog

data processing level

and the definitions thereof. The CSES data are divided into five levels (0—4). The general data processing procedure and the associated products were introduced. The data processing procedures of Levels 1 and 2 and the key algorithms of each scientific payload were described in detail.