The ESA Swarm Dissemination Server is now also hosting a mirror of the CASSIOPE/e-POP full data archive (past and current observations) in native format. These products are freely available under the /#CASSIOPE_e-POP directory by FTP/HTTPS anonymous browsing. Read a full description of the e-POP data set.

CASSIOPE is a Canadian satellite that carries the Enhanced Polar Outflow Probe (e-POP) science payload for the study of ionospheric plasma outflow, radio wave propagation, dynamic aurora processes, neutral atmosphere escape, and more. Launched in 2013 into an elliptical polar orbit (325 km x 1500 km at 81° inclination), e-POP is capable of high time-resolution measurements for investigation of the micro- and mesoscale physics of the ionosphere-magnetosphere-thermosphere system.

Since March 2018, CASSIOPE/e-POP mission is formally integrated into the Swarm constellation as the fourth element (Swarm-Echo) under ESA's Earthnet Third Party Mission Programme. The e-POP payload operations are currently focused on maximising the Swarm/e-POP scientific outcome, and there is an ongoing joint effort to develop new better calibrated products based on e-POP data.

The e-POP payload is a collaboration developed by six Canadian universities and companies and two international partners and is composed of the following experiments:

• Fluxgate Magnetometer (MGF): A two-sensor, 3-axis fluxgate magnetometer capable of measuring the local magnetic field at 160 Hz (spatial scales down to 100 m), to a resolution of 62.5 pT
• GPS Attitude, Position, and profiling experiment (GAP): Five NovAtel differential GPS receivers able to sense L1 and L2 signals at up to 100 Hz provide measurements from topside and occulting GPS satellites simultaneously
• Fast Auroral Imager (FAI): Imaging once per second the FAI can capture the aurora in the near infrared (650 – 1100 nm) and visual (630 nm) bands over fields-of-view spanning 100-630 km
• Imaging and Rapid-scanning Ion mass spectrometer (IRM): The IRM measures ions in the 0.1–100 eV-per-charge range, with mass resolution of ions ranging from 1-40 amu-per-charge. Imaging at up to 100 Hz, IRM can detect ions on spatial scales of 70-80 m
• Radio Receiver Instrument (RRI): Measuring wave electric fields in the range of 10 Hz to 18 MHz, the three-metre RRI antennas are capable of detecting natural and artificial signals from 1 µV/m to 1 V/m, with a bandwidth of 30 kHz
• Coherent Electromagnetic Radiation tomography experiment (CER): A tri-frequency radio beacon used to transmit 150, 400, and 1067 MHz signals to ground, for determination of radio propagation and ionospheric scintillation measurements provided by the US Navy
• Suprathermal Electron Imager (SEI): The SEI measures the electron energy and pitch angle distribution for electrons in the 1-200 eV energy range, 100 times per second
• Neutral Mass Spectrometer (NMS): A first generation instrument, NMS aims to measure the mass composition and velocity of neutral atmospheric species in the 1-40 am mass and 0.1-2 km/s velocity range provided by the Japan Aerospace Exploration Agency (JAXA)