1. Ionospheric Science and Space Weather
GNSS data for
Ionospheric Science and Space Weather
Anthea Coster
MIT Haystack Observatory

2. 2. Illustrate the current uses of network data
1. Elucidate the current state of the network
2. Illustrate the current uses of network data
3. Identify potential new utility of the data
4. Determine the optimal configuration moving forward: Ideal number of stations, Placement of stations, Replacement and upgrade of stations, Data management.
- how does your science use the current GNET?
- to what extent does your work depend on the entire network?
- how could the network be improved to support your work?
- what new work could be enabled with this network, related to your work or not?

4. Strong growth in GNSS applications - surveying, drilling, precision agriculture, navigation, aviation Space weather leads to degradation in accuracy or availability
IONOSPHERE

5. SPACE WEATHER

6. Near-Earth Space: Solar-Terrestrial Interaction
Shue et al.
magnetopause (blue)
Radiation, solar wind (hydrogen+ and e-) and IMF; 8 minutes for radiation to reach earth and 2-4 days for solar wind to reach earth
Ths is driver of space weather

7. Near-Earth Space: Terrestrial Environment
Dipolar configuration does not support polar patches, aurora or storm enhanced density

8. The Aurora
Altitudes of aurora

9. Increase in background noise level due to solar radio bursts
How can we predict the occurrence of, and reaction to, Space Weather? Strong growth in GNSS applications - surveying, drilling, precision agricultures, navigation, aviation Space weather leads to degration in accuracy or availability
Large scale TEC gradients
Rapid change in the TEC
due to solar flare
Increase in background noise level due to solar radio bursts
Scintillation
you heard yesterday from Dale Gary about the effect of solar radio bursts to the operation of high precision GNSS systems - and where you see all these red dots is when these systems could not provide their results. Overhere you see the rapid change in tec in an 8 minute period following an x-class solar flare.

10. Storm-Enhanced Density
Severe ionosphere gradients
Impact on DGPS and SBAS positioning applications, among others

11. Space Weather: Gradients over the Poles
Space weather can be defined as anomalous electron density strutures such as the storm endhanced electron density feature (which is represented by the red) seen below which converts into the tongue of ionization over the poles. This example is of the total electron content over the poles.

14. Enhanced TEC measured at ~ 24 UT

15. nain

16. Space Weather - Scintillation
SV velocity vs
Plasma drift vp
Wave front:
uniform phase
uniform amplitude
Incident wave
Ionosphere
Irregularities
Wave emerging from
below irregularities:
non-uniform phase
quasi-uniform/non-uniform amplitude
Diffraction/interference pattern
Ground

17. The Aurora Polar Region Auroral Oval
What altitude distribution of irregularities? Differs polar cap versus auroral region due to different nature of phenomena (open versus closed magnetic field lines etc.)

18. Example: Auroral Arc Near South Pole
All-sky imager
(120 km altitude)
(G. Bust)
GPS signal

19. Auroral Arcs and Scintillation
ASI field of view; keogram
 (rad)

20. Patchy Pulsating Aurora
Different types of aurora occur – patchy pulsating versus bright discrete arcs. Effects on GNSS signals can differ.

21. E. G. Thomas
GPS TEC & SuperDARN
CEDAR-GEM, 2011

22. TRAVELING IONOSPHERIC DISTURBANCES

24. This develops into TIDS

27. 2. Illustrate the current uses of network data
1. Elucidate the current state of the network
2. Illustrate the current uses of network data
3. Identify potential new utility of the data
4. Determine the optimal configuration moving forward: Ideal number of stations, Placement of stations, Replacement and upgrade of stations, Data management.
- how does your science use the current GNET?
- to what extent does your work depend on the entire network?
- how could the network be improved to support your work?
- what new work could be enabled with this network, related to your work or not?