The CARINA Satellite Mission to Study the Lower Thermosphere

Abstract:

The Naval Research Laboratory has constructed two satellites called CARINA to fly below the F-Layer ionosphere for a period of 45 to 60 days. The Space Plasma Mission will study (1) HF radio propagation in the ionosphere, (2) sporadic-E layer characterization, and (3) global imaging of F-Layer ionosphere. The CARINA spacecraft will be launched in 2016 into a 51.6° inclination orbit that has in initial insertion of 178 km by 284 km. The instruments on CARINA are (1) Electric Field Receiver (EFI) measuring electrostatic and electromagnetic waves in the MF/HF Band (3 to 13 MHz), (2) Ram Langmuir Probe (RLP) measuring the electron concentration in the 10² to 10⁶ cm^-3 range and the (3) Orbiting GPS Receiver (OGR) to record TEC in the F-Layer above the satellite. The six areas of research are (a) Sporadic-E/Intermediate Layers and TIDs with a focus on ionospheric structures below orbit and large scale bottomside fluctuations in the F-Layer, (b) global assimilation for using the CARINA OGR and RLP observations as drivers for data driven ionospheric models such as GAIM, IDA3D, etc., (c) HF propagation and radio scintillations to determine the impact of the bottomside ionosphere on HF ray trajectories for SuperDARN, ionosondes, etc., and to determine the effects of ionospheric irregularities and UHF/L-Band scintillation on GPS, etc., (d) lightning and ocean waves to directly measure lightning EM pulses and determine their impact on the ionosphere as well as derive ocean wave height spectrum from HF surface wave scatter, (e) Langmuir waves excited by photoelectrons during the daytime and high power HF transmitters, and (f) satellite drag with thermosphere/mesospheric density updates determined by orbit measurements and reentry modeling of drag coefficients. CARINA will employ ground HF beacon transmitters, incoherent scatter radars, and other instrumented satellites such as the Canadian ePOP/CASSIPE spacecraft for coordinated observations. By staying in orbit for an extended period with an average altitude of 200 km, CARINA will observe the connections between the underlying troposphere (lightning and ocean waves) and mesosphere (E-layers) with overlying F-region ionosphere. Because, CARINA will fly “where no satellite has flown before”, there will be an immediate enhancement