The NASA EQUIS II (Equatorial Ionosphere Studies) campaign was conducted in August/September 2004 at U.S. Army Kwajalein Atoll/Reagan Test Site on Roi-Namur, Marshall Islands (9° N, 168° E). The LEMMA (Layers in the Equatorial Mesosphere, Motions and Aerosol) program was devoted to neutral and plasma density fluctuations in the equatorial mesosphere and lower thermosphere. One objective was to detect layers of small scale structures that might be related to mesospheric VHP radar echoes observed regularly at equatorial and low latitudes. The payload carried multiple instruments from U.S. and European investigators, including an ionization gauge for the first in situ measurements of neutral turbulence fluctuations in the equatorial mesosphere. One sounding rocket and three falling spheres were launched successfully on September 20, 2004, supported by a large, steerable 422 MHz UHF radar receiving incoherent backscatter from ∼85-700 km. We give an overview of the investigation and present some results including the comparison of in situ and ground based electron density measurements, neutral temperature and wind structure, and observations of neutral and electron density fluctuations.
|Original language||English (US)|
|Number of pages||6|
|Journal||European Space Agency, (Special Publication) ESA SP|
|State||Published - 2005|
ASJC Scopus subject areas
- Aerospace Engineering