Preliminary HF results from the Metal Oxide Space Cloud (MOSC) experiment

Artificial Ionospheric Modification (AIM) can occur through deliberate or incidental injections of aerosols, chemicals or radio (RF) signals into the ionosphere. The Metal Oxide Space Clouds (MOSC) experiment was undertaken in April/May 2013 to investigate chemical AIM. Two sounding rockets were launched from Kwajalein Atoll and each released a cloud of vaporized samarium (Sm). The samarium created a localized plasma cloud that formed an additional ionospheric layer. The effects were measured by a wide range of ground based instrumentation; this included a 17 channel direction finding chirp receiver. This system detected the new layer which remained visible to the HF sounder for approximately 25 minutes. The layer's maximum usable frequency peaked at approximately 10 MHz immediately after release. The direction to the reflection point remained constant at 355° whilst the new layer was visible to the sounder.