Operational Impacts of Space Weather

Operational Impacts of Space Weather R. Lambour, A. J. Coster, R. Clouser, L. E. Thornton, J. Sharma, and A. Cott 2001 Space Control Conference 3 April 2001 2001 Space Control Conf. -1

Outline Introduction Space Weather Effects on Space-Based Systems Effects on Ground-Based systems Conclusions 2001 Space Control Conf. -2

Definition: Space Weather Conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can affect performance and reliability of space-based and ground-based technological systems. * 2001 Space Control Conf. -3 *

Effects of Space Weather on Earth SOHO Solar Flare SOHO Coronal Mass Ejection Solar Flare of 14 July 2000 Biggest Solar Storm in Nine Years Caused very large magnetic storm and ionospheric effects Near peak of 11 Year solar cycle Activity on Sun, magnetosphere and ionosphere will be a maximum for the next 2-3 years 2001 Space Control Conf. -4

Outline Introduction Space Weather Effects on Space-Based Systems Space-Based Visible sensor South Atlantic Anomaly Transient effects Long-term (?) effects Effects on Ground-Based systems Conclusions 2001 Space Control Conf. -5

SBV Sensor 15 cm high straylight rejection telescope 4-420x420 Lincoln Laboratory CCD 1.4 x 1.4 deg field of view per CCD Staring sensor 2001 Space Control Conf. -6

SBV Sensor 15 cm high straylight rejection telescope 4-420x420 Lincoln Laboratory CCD 1.4 x 1.4 deg field of view per CCD Staring sensor Target and star detection Clutter rejection Data compression 2001 Space Control Conf. -6

Space Environment Effects on SBV 2001 Space Control Conf. -7

South Atlantic Anomaly (SAA) Flux contours of E > 50 MeV Protons at 500 km SAA Energetic particle enhancement at low altitudes due to offset of magnetic field 2001 Space Control Conf. -8

SAA Effects on SBV 2001 Space Control Conf. -9 Protons with energy > 10 MeV affect SBV focal plane and inhibit ability to observe valid target streaks

Transient Effects: 14 July 2000 Solar Proton Event Solar Proton Arrival NOAA Geosynchronous Space Environment Summary 2001 Space Control Conf. -10

Transient Effects: 14 July 2000 Solar Proton Event Valid Streaks per Frameset 2.0 1.5 1.0 0.5 Latitude < 60 Latitude > 60 Flare Storm 0.0 190 192 194 196 198 200 Day of Year 2000 Solar flare occurred at end of pinch point CONOPS testing One DCE produced no data (day 197) Decrease in valid streaks over polar regions seen Decrease not attributable to anomalies 2001 Space Control Conf. -11

Transient Effects: 14 July 2000 Solar Proton Event False Streaks per Frameset 2.0 1.5 1.0 0.5 Latitude > 60 Latitude < 60 Flare Storm False streaks per frameset increased significantly after solar flare 0.0 190 192 194 196 198 200 Day of Year 2000 2001 Space Control Conf. -12

Long Term (?) Space Environment Effects SAA 2001 Space Control Conf. -13

Long Term (?) Space Environment Effects SAA Area with reduced detections south of SAA noticed in 1998-1999 Effect investigated by looking geographic distribution of valid and false streaks 2001 Space Control Conf. -13

Long Term (?) Space Environment Effects SAA Region of interest 2001 Space Control Conf. -14

Long Term (?) Space Environment Effects SAA Region of interest Area of degraded performance persists into 2000 2001 Space Control Conf. -14

Energetic Particle Source Regions > 6900 kev proton data from NOAA POES MEPED sensor **SEM-2 system 2001 Space Control Conf. -15 0 -detector SAA 90 -detector Trapped Protons NOAA baseline plots show increase in trapped outer-zone protons south of SAA in recent years Consistent with location of degraded SBV performance

Outline Introduction Space Weather Effects on Space-Based systems Effects on Ground-Based systems Range Delay Scintillation July 14-15 th storm Conclusions 2001 Space Control Conf. -16

2 m 2 2001 Space Control Conf. -17

Illustration of Atmospheric Effects Range Delay n ionosphere 1 AN f e 2 R ion ( meters) 40. 3 = 2 f R 0 N dr e 2001 Space Control Conf. -18

Illustration of Atmospheric Effects Range Delay n ionosphere 1 AN f e 2 R ion ( meters) 40. 3 = 2 f 0 R N dr e Range Delay S-Band L-Band UHF VHF Elev Ionosphere 6 m 32 m 280 m 2 km < 20 2001 Space Control Conf. -18

GRIMS: GPS Real-Time Ionospheric Monitoring System built the first real-time ionospheric monitoring system based on GPS (1991). Purpose: Part of a radar calibration system. Operational systems online at FPS-85, ALTAIR, and Millstone satellite tracking radars. TEC as Function of Azimuth and Elevation around Millstone Hill Radar, MA 2001 Space Control Conf. -19

Scintillation Scintillation can cause additional errors. For GPS, the primary issue is loss of lock. For radars, the primary issue is degradation of coherent integration capabilities. 2001 Space Control Conf. -20

ALTAIR VHF Observations on CAL Sphere 2826: Normal Conditions versus Severe Scintillation ALTAIR VHF Tracks Calibration Sphere 2826.5 m diameter, 850 km circular orbit Power spectral density (log) -10 Spectrum dbnormal 10-5 0 5 Frequency (Hz) RCS (dbsm) 10 0-10 -20-30 -40-50 10 0-10 -20-30 -40-50 10 64900 RCS (dbsm) Negligible scintillation 65100 65200 65300 65400 G M T S E C O N D S Time of day (sec GMT) 65500 64800 64900 65000 65100 65200 65300 65400 Power spectral density (Log) -10 Spectrum in Severe Scintillation 2001 Space Control Conf. -21-5 0 5 10 Frequency (Hz) RCS (dbsm) 10 0-10 Moderate scintillation Intense scintillation -20-30 Cable -40 wrap -50 44000 44100 44200 44300 44400 44500 44600 Time of day (sec GMT)

Biggest Solar Storm in Nine Years Strikes Earth Solar Flare of 14 July 2000 2001 Space Control Conf. -22

Biggest Solar Storm in Nine Years Strikes Earth Solar Flare of 14 July 2000 Est. Planetary Kp (3 Hr.) Begin: 2000 Jul 14 0000 UT es 2001 Space Control Conf. -22 NOAA/SEC Boulder, CO USA

TEC Disturbances on 15 July 2000 TEC Units 180 160 140 120 100 80 60 40 20 0 POR4 WES2 NRC1 MHR3 EGL2 0 5 10 15 20 25 30 UTC Time (Hours) starting at day 197 2001 Space Control Conf. -23

GPS Loss of Lock at Ottawa and Millstone Hill GPS Loss of Lock at Ottawa Local Westward Ion Velocity at Millstone Hill V West (m/s) No. of Satellites TEC units units 4 5 4 0 3 5 3 0 2 5 2 0 1 5 1 0 5 Zenith TEC Over Millstone Hill Loss of Lock on GPS L2 signal 2001 Space Control Conf. -24 0 1 5.5 1 5.7 5 1 6 1 6.2 5 1 6.5 15.5 15.75 Day of 16 Month D a y o f M o n t h 16.25 16.5

Range Residuals on Calibration Sphere 7646 FPS-85 Florida Range Residuals (m) Range Residuals (m) 350 250 Typical Residuals 150 50-50 201.87 201.872 201.874 201.876 201.878 201.88 400 300 July 15 th storm effects 200 100 0 197.968 197.97 197.972 197.974 197.976 2001 Space Control Conf. -25 Day of Year (2000)

Summary Space-Based Visible sensor sensitive to proton radiation environment (e.g., SAA) Transient effects (solar proton events) can degrade SBV performance Long-term changes in the radiation environment may also affect performance of space-based sensors Ground-based radar measurements: ionosphere introduces errors Range Delay and Angle Errors Scintillation In general, geomagnetic storms make these errors larger and harder to model Understanding of space environment facilitates future spacebased and ground-based systems 2001 Space Control Conf. -26