Observations of LHR noise with banded structure by the Sounding Rocket S29 Barium‐GEOS

We report here the measurement of electrostatic noise near the lower hybrid frequency made by the sounding rocket S29 barium‐GEOS. The noise is related to the spin of the rocket and reaches well below the local lower hybrid resonance frequency. Above the altitude of 300 km the noise shows banded structure roughly organized by the hydrogen cyclotron frequency. Simultaneously with the banded structure a signal near the hydrogen cyclotron frequency is detected. This signal is also spin modulated. The character of the noise strongly suggests that it is locally generated by the rocket payload disturbing the plasma. If this interpretation is correct, we expect plasma wave experiments on other spacecrafts to observe similar phenomena.