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Indian Journal of Radio & Space Physics (IJRSP) >
IJRSP Vol.41 [2012] >
IJRSP Vol.41(2) [April 2012] >
| Title: | Impact of equatorial ionospheric irregularities on transionospheric satellite links observed from a low-latitude station during the minima of solar cycle 24 |
| Authors: | Das, T
Roy, B
Gupta, A Das
Paul, A |
| Keywords: | Equatorial ionospheric irregularities
Transionospheric communication
Carrier-to-noise (CNO) ratio
Position dilution of precision (PDOP)
Equatorial electrojet (EEJ) strength
Slant total electron content (STEC) |
| Issue Date: | Apr-2012 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 94.20.dt; 94.20.Vv; 84.40.Ua |
| Abstract: | Effects of equatorial ionization density irregularities on transionospheric
communication and navigation links have been studied during the abnormally
prolonged minima of the 24th solar cycle from Calcutta, a station situated
virtually underneath the northern crest of the equatorial ionization anomaly in
the Indian longitude sector. Scintillations at L-band have been sparse during
2008-2010 with four cases of GPS scintillations being observed from Calcutta.
It is interesting to note that all these cases of scintillations were observed
when the irregularities were field-aligned. One of the cases occurred on 25
September 2008 when GPS SV12 link exhibited depletions in TEC of nearly 8 TEC
units around 15:30 hrs UTC associated with fluctuations in carrier-to-noise
(CNO) ratio at L1 frequency and position dilution of precision (PDOP). The
1-min S4 index reached a maximum value of 0.48 [SI~11dB] on the SV12
link around 15:30 hrs UT. The geostationary FLEETSATCOM link at 250 MHz was
also disrupted during the period 15:55-16:25 hrs UT with maximum S4
of
0.69 [SI~17dB]. The ambient ionization and strength of the equatorial
electrojet was higher on that day than other days around that period. The F-region height rise around sunset
was significant as indicated by a flat-topped ionization density distribution
over the magnetic equator by Defense Meteorological Satellite Program (DMSP). |
| Page(s): | 247-257 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.41(2) [April 2012]
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