Post on 16-May-2020
A lesson and Learn from F3/C ionospheric A lesson and Learn from F3/C ionospheric
Observations for F7/C2Observations for F7/C2
2011.04.13
Tiger J. Y. LiuNational Space Organization
National Central University
1
Content
• Introduction
• Space-Space Tomography- 2D TIP+GOX Tomography- 2D TIP+GOX Tomography
- 3D TIP+GOX Tomography
- 2D TIP Tomography
• GOX N(500 km) vs. N(800)
• Conclusion
2
2000 40003000
5000 6000 7000
Hei
gh
t(k
m)
IRI
Result
8000 9000 10000
Hei
gh
t(k
m)
Electric density(#/cm3)7 7
Grid :
Longitude <5°°°°> , Latitude <5°°°°> ,
Altitude<25km>
Result: IRI (2008-74-06)
3D tomography simulated
Initial Guess : uniform 1000 electron density (#/cm3)
Occultation Case :
2008-91~2008-93
COSMIC GOX data
(4500)
Nadir Sounding:
2008-91~2008-93
COSMIC orbit data
Height:0-800km
Sampling Rate:1min
(480km)9
Error of Tomography & Abel Inversion
Space-Space
Tomography
ABEL Inversion
Use Occultation
and Nadir
Sounding data for
tomography
Use Occultation inverted
electron density profile
12
Remark (1)
• The GOX and TIP observations provide the
vertical distribution and horizontal gradient
of the electron density, respectively.
• The space-space tomography yields a better • The space-space tomography yields a better
performance, which can be use to derive 3D
structure and dynamics of the ionospheric
electron density.
• A nadir sounder is essential for the F7
mission.
Experiment Setup
• Use IRI to simulate the ionosphere
• Satellite (800km altitude, polar orbit)
• Photometer Sounding (1 Hz sampling rate,
135.6nm)
- 1 nadir photometer (F3/C TIP)
- 1 nadir and +45°°°° photometers
- 1 nadir, +45°°°°, and -45°°°° photometers
• Apply MART conducting the
Inversion/tomography (horizontal x vertical
resolution: 40kmx20km)
• Conclusion
Initial Guess (NmF2:10000#/cm3, hmF2:
250km)
1 nadir PhotometerA
ltit
ude
(km
)
el/cm3
Alt
itude
(km
)
Range (km)
IRI
Alt
itude
(km
)
IRI vs. 1 nadir Photometer Inversion
1 nadir Inversion
Alt
itude
(km
)
Range (km)
el/cm3
IRI
Alt
itude
(km
)
el/cm3
IRI vs. 1 nadir & +45 Photometer Tomography
1 nadir & +45 Photometer TomographyAlt
itude
(km
)
Range (km)
el/cm3
IRI
Alt
itude
(km
)
el/cm3
IRI vs. 1 nadir & +/- 45 Photometer Tomography
Alt
itude
(km
)
Range (km)
el/cm3
1 nadir & +/- 45 Photometer Tomography
Remark (2)
• The multi-photometer observation can be used
to reconstruct the height-latitude 2-D
ionosphere.
• The observation with nadir, +45°°°°, and -45°°°°• The observation with nadir, +45°°°°, and -45°°°°
photometers yields a batter tomography result.
• Time: 2007.061 ~ 2007.120
• UT: 12:00 ~ 14:00
• Longitude : -180 ~ 180• Longitude : -180 ~ 180
• Latitude : -60 ~ 60
• Altitude : 0 ~ 800km
Conclusion
• The F7/C2 TriG together with TriP shall
provides a better resolution and accuracy for
the ionospheric electron density probing. the ionospheric electron density probing.
• The electron densities derived by the F7/C2
GOX should be carefully investigated.