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CITRIS: The Cosmic Companion for LEO Radio Occultation

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.

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CITRIS: The Cosmic Companion for LEO Radio Occultation

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  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

  2. Computerized Ionospheric Tomography Radio Instrument in Space (CITRIS) • NRL Radio Plasma Sensors in Space • ARGOS, PICOSat, C/NOFS, NPSAT1, STPSAT1, COSMIC, ISE/SCITRIS II • Radio Beacon Systems • NRL Langmuir Probe • CITRIS Objectives • Global Ionospheric Monitoring • Medium Resolution Irregularity Imaging • Scintillation Detection and Prediction • Radio Science Experiments • Conclusions

  3. CITRIS on STPSAT1 (2006) CERTO/LP on NPSAT1 (2006) SCITRIS I (2006) NRL Radio Beacon Sensors in Space CERTO on C/NOFS (2003) CERTO on ARGOS CERTO on PICOSat (2001) (1999-2001) CERTO on COSMIC (2005) ISE/SCITRIS II (2005)

  4. Radio Beacon Sensor Timelines Satellite ARGOS DMSP/S15 PICOSat STRV-1D C/NOFS COSMIC (6) SCITRIS II NPSAT1 STPSAT1 NPOESS 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Calendar Year

  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”) • Tri-Band Beacon RF Outputs • 150.012 MHz 27 dBm • 400.032 MHz 30 dBm • 1066.752 MHz 32 dBmStability: 1 part in 1010 Over 1 Orbit • Stability: 1 part in 1010 Over 1 Orbit • Input Power: 28 VDC at 12.8 Watts • Output Control: 150/400 On/OF 1067 On/OFF • Used on C/NOFS, COSMIC, NPSAT1 • Made by Syntech Microwave Inc. • Designed by NRL Codes 6794 and 8131 • Radiation Resistant to 40 kRad • Internal Watch-Dog Timer for SEU

  7. ADC ADSP- 21060 RF ADC GC4014 ADC Spacecraft Interface 7.93 cm [3.119”] CITRIS Receiver for SPTSAT1 26.99 cm [10.625”] Inputs from Antenna 20.96 cm [8.25”] Control CERTO 12-bits IF 150 MHz 400 MHz IF 12-bits Link Port 1067 MHz IF 12-bits 2036 MHz DORIS Clock ACK SYNC Serial Out Serial In Power Supply 5V DSP 28 Volts 5V ADC 5V RF

  8. CERTO/TBB Accommodations on COSMIC CERTO Beacon Boom Magnetometer Nadir Reflectors Trapped Antenna Radiators

  9. Deployed Arrays CITRIS Antenna CITRIS Receiver STPSAT1 SCITRIS I Ionospheric Instruments CERTO Three Frequency Monopole Antenna NPSAT1 Ram Velocity NRL Langmuir Probe (NLP)

  10. Radio Sources for Ionospheric Measurements VHF/UHF Satellite Beacons in Low Earth Orbit 30 Total (NIMS, CERTO, …) L-Band GPS Beacons Globally Distributed 24 Total UHF/S-Band Ground Beacons Globally Distributed 54 Total (DORIS)

  11. (c) (b) Contact Duration (772 Seconds Maximum) Site Contacts (8 Max.) DORIS Ground Beacon Contacts (35o Inclination)265 Total Contacts Over 24 Hours

  12. CERTO Beacon Transmitter on COSMIC Ionosphere N Ground Receivers DORIS Transmitters S CITRIS Receiver on STPSAT1 and ISE/SCITRIS II LEO Orbit MULTI-DIRECTION GEOMETRYFOR SCINTILLATION AND TEC MEASUREMENTS

  13. TEC, Scintillation and Tomography CERTO Beacon on COSMIC and NPSAT1 Orbit Irregularity 140/400/1067 MHz Receiver

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

  15. TEC, Scintillation and Tomography CERTO Beacon on NPSAT1 and COSMIC Orbit Irregularity CITRIS Receiver on STPSAT1 DORIS 140/400/1067 MHz Receiver 401.25/2036.25 MHz Transmitter

  16. CERTO/LP on NPSAT1 Tandem Operations Scintillation and Ionospheric TomographyRadio Instrument in Space (SCITRIS I) CITRIS on STPSAT1 RF Link

  17. Vertical TEC (1016 m-3) CITRIS/CERTO OVERVIEW Program Goals • Detect when and where radiowave propagation through the ionosphere is adversely affected by scintillation and refraction • Provide a global map of ionospheric densities and irregularities NRL SAMI3 TEC Predictions SCINTMOD Scintillation Predictions

  18. 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 Radio Beacon Science Experiments Note: C = COSMIC S = SPTSAT1 N = NPSAT1

  19. Space-to-Ground Propagation Through an Ionospheric Irregularity Downward Ionospheric Propagation Distortion at 400 MHz Amplitude (dB) Phase (Radians) East-West Distance (km)

  20. Tandem Satellite Observations of Ionospheric Irregularities

  21. Electron Density (105 cm-3) 0 2 4 6 8 STPsat1 Position 15 0 Amplitude (dB) -15 Plume Altitude (km) Ne Peak Predictions of Scintillations from a CITRIS Receiver at 800 km Altitude Zonal Distance (km)

  22. Irregularity Measurementsand Radio Scintillations Sampled Density, ne Electron Density (105 cm-3) Sampled Fluctuations, dne/ne Ne Peak Plume Zonal Distance (km) VHF Ground Level: Large Scintillations Langmuir Probe at 550 km Amplitude (dB) -30 dB Signal Dropouts Zonal Distance (km)

  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.

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