Composition of the Topside Ionosphere Determined from Plasma Wave Measurements Using the Radio Receiver Instrument on e-POP

Data were collected with Canadian e-POP instruments to measure electric fields (10 Hz to 30 kHz) with the Radio Receiver Instrument (RRI) and the 3-axis magnetometer (MGF) in the 62.5 pt to 65.536 μt range. The electric field measurements showed waves ULF (210 Hz) and VLF (14 kHz) range that varied along the orbit and were disturbed by the firing of the Cygnus satellite rocket motor 50 km away. A number of questions are raised by the observations including: Are the observations attributable to Cygnus? Are the observed harmonics instrumental or physical? What are the plasma wave generation and propagation modes? The observations are used to infer natural and artificial changes in the ionosphere.