CITRIS: The Cosmic Companion for LEO Radio Occultation

1. CITRIS: The Cosmic Companion for LEO Radio Occultation P.A. Bernhardt C.L. Siefring J.D. Huba C.A. Selcher Plasma Physics and Information Technology Divisions Naval Research Laboratory Washington, DC 20375 COSMIC Radio Occultation Workshop 21 August 2002 Boulder, Colorado

3. NRL Radio Beacon Sensors in Space

4. Radio Beacon Sensor Timelines

5. Beacon Sensor Instrumentation Space Hardware CERTO Beacon on C/NOFS, COSMIC and NPSAT1 150.012, 400.032, 1066.752 MHz ~1 Watt with No Modulation CITRIS Receiver on STPSAT1 Bands at 150, 400 or 401.25, 1067 or 2036 MHz -140 dBm Sensitivity DSP of 10 MHz IF I and Q TEC, S4, sf, FFT and Raw Data Products Langmuir Probe on STPSAT1 Ground Support Instruments DORIS Beacon Transmitters (401.25, 2036.26 MHz) TEC and Scintillation Receivers Global Existing Networks at 150/400 MHz (SCINDA, CIDR, CITRIS) New Systems Using 150/400/1067 MHz (South America, India, Pacific) Ground Incoherent Scatter Radars Electron Density Profiles/Field Aligned Irregularities Jicamarca Radio Observatory Arecibo Ionospheric Observatory

6. TBB/CERTO Beacon (3� x 5�)

7. CITRIS Receiver for SPTSAT1

9. SCITRIS I Ionospheric Instruments

10. Radio Sources for Ionospheric Measurements

11. DORIS Ground Beacon Contacts (35o Inclination) 265 Total Contacts Over 24 Hours

12. MULTI-DIRECTION GEOMETRYFOR SCINTILLATION AND TEC MEASUREMENTS

13. TEC, Scintillation and Tomography

14. ARGOS Beacon Orbit Flight Over the Caribbean17 September 1999, 0650 UT (ARL/UTA CIC�99)

15. TEC, Scintillation and Tomography

16. Scintillation and Ionospheric TomographyRadio Instrument in Space (SCITRIS I)

17. CITRIS/CERTO OVERVIEW

18. Radio Beacon Science Experiments Radio Frequency Interpolation Test (C/S/N) Multiple Frequency Transmission Measurements at Frequencies 150 and 1067 MHz Predictions for Arbitrary Frequency Validation Using Measurements at 400 MHz In-Situ Probe for Propagation Estimation (N/S) Langmuir Probe Detection of Electron Density Fluctuations From Langmuir Probe Estimate Phase Screen Model Compute Scintillation Amplitude at Selected Frequencies Validate Phase Screen Model Mode Coupling: Quasi-Transverse (QT) Propagation (C/S/N) Radio Science Investigation Near Magnetic QT Points O-Mode Transmission X- or O-Mode Reception Diagnostic of Ionosphere Near QT Point Single Frequency Reciprocity Tests (C/S/N) Multiple frequencies (150, 400, and 1067 MHz) Common Paths for Uplinks and Downlinks Implementation: T/R Pulsing at 10 ms With PN Sequence Global Ionospheric Mapping (S/C) Continuous Monitoring of the 6 COSMIC Space Beacons and 54 DORIS Ground Beacons 401.25 and 2036.25 MHz Reception TEC and Scintillation Measurements in Space Faraday Rotation and Differential Doppler Imaging (N/S/C) High Resolution Local Mapping Ground Measurement Polarization Angle at Each Frequency Differential Phase Between Frequency Pairs Multiple Frequencies (150, and 400 MHz) Tomography Using TEC and Faraday Content

20. Tandem Satellite Observations of Ionospheric Irregularities

22. Irregularity Measurementsand Radio Scintillations

23. Conclusions The 6 COSMIC satellites launched in late 2005 will be supported for ionospheric studies by the NPSAT1 and STPSAT1 vehicles to be launched in tandem in January 2006 These satellites, which are sponsored by the Air Force Space Test Program and the Naval Post Graduate School in Monterey, contain radio and in situ diagnostic instruments to study the ionosphere. The CITRIS receiver provides rare opportunities to perform two-way propagation experiments between space and ground and one way experiments from space-to-space. Current Experiments Cover (1) Global Ionospheric Mapping, (2) Fundamental Radio Propagation Studies, and (3) Scintillation Observations and Prediction.