Cyprus Embraces Space Haris Haralambous presentation

1. Exploiting Space and Earth-based Instrumentation for
Atmospheric Studies in Cyprus
Haris Haralambous
Department of Electrical Engineering
Frederick University
“Cyprus Embraces Space 2016” Conference
Wednesday, 18th May 2016
European University Cyprus

2. Outline
• INTRODUCTION
• THE IONOSPHERE
• THE SUN AS THE MAIN SPACE WEATHER
DRIVER
• SPACE WEATHER
• IONOSPHERIC EFFECTS ON RADIO
SYSTEMS
• IONOSPHERIC MONITORING
• IONOSPHERIC RESEARCH AT FREDERICK

3. • The ionosphere is the uppermost
part of the atmosphere and is
ionized by solar radiation.
• Ionization is the conversion of
atoms or molecules into an ion by
light (heating up or charging) from
the sun on the upper atmosphere.
• Ionization also creates a horizontal
set of stratum (layer) where each
has a peak density and a definable
width or profile that influences
radio propagation.
IONOSPHERE

4. D region: (60÷90 km) mainly responsible
for the radiowave absorption.
E region: (90÷150 km) reflects the long
and medium radiowaves (λ>100 m).
F region: (150÷400 km ) reflects the short
radiowaves.
F region: (150÷400 km ) reflects the short
radiowaves.
IONOSPHERE

5. This means that people who broadcast from
the Earth using HF frequencies can use the
ionosphere like a mirror (an electromagnetic
mirror) to bounce their signals anywhere in the
world.
The ionosphere can distort radio
signals from satellites.
High Frequency (HF, 3-30 MHz)
or short-wave radio signals can
be reflected by the ionosphere.
IONOSPHERE

6. THE SOLAR CYCLE

7. SOLAR CYCLE VARIATION OF IONOSPHERIC CHARACTERISTICS
The main causes of large scale variations in ionospheric layers are related to the 11-year
solar cycle. The last solar cycle peak occurred in 2000-2001. The current cycle peak is
progressing through its maximum phase.

8. SATCOM OUTAGE REGIONS

9. IONOSPHERIC STRUCTURE IN SPACE

10. IONOSPHERE-THERMOSPHERE PROCESSES

13. MULTIPLE DAY SPACE WEATHER EVENT BY SOHO
(Solar and Heliospheric Observatory)

15. ANIMATED SPACE WEATHER EVENT
A coronal mass ejection (CME) is an ejection of material from the solar corona..The ejected
material is a plasma consisting primarily of electrons and protons. When the ejection reaches the
Earth, it may disrupt the Earth's magnetosphere. When the magnetosphere reconnects on the
nightside, it creates trillions of watts of power which is directed back toward the Earth's upper
atmosphere.

18. THE SKYLAB CRASH
•Track and identify active payloads and debris (DOD)
•Collision avoidance and re-entry prediction (NASA)
•Study the atmosphere’s density and temperature profile (Science)
Skylab, 1978
April 9, 1979

19. CYPRUS DIGITAL IONOSONDE (digisonde)
More than 15 ground-based ionosondes are currently available covering European
ionosphere. The recently started Nicosia DPS-4D ionosonde station is expected to
introduce new opportunities for real-time ground based ionospheric operations in
the Mediterranean area.
Rome (41.8°N, 12.5°E)
Ebro (40.8°N, 0.3°E )
Athens (38.0°N, 23.5°E)
Nicosia (35.1°N, 33.3°E)
Gibilmana (37.9°N, 14.0°E)
El Arenosillo (37.1°N, 353.3°E )

20. CYPRUS DIGITAL IONOSONDE INSTALLATION IN 2008

21.  The increase of electron density of
ionosphere can be monitored and
displayed by ionosondes.
 Ionosondes are radars that
measure the electron density of the
ionosphere up to the maximum
electron density by means of
bottom-side radio sounding.
 Regular radio sounding are made
from Nicosia station since 2009. The
data is open for public access via
Digital Ionogram DataBase
(DIDBase) and Digital Drift
DataBase (DriftBase) Web Portals.
Our ionosonde data provides 5
minute values in automatically
scaled form.
IONOSONDE OPERATION

22. THE IONOGRAM
The ionogram is the record produced by the ionosonde which shows the time delay
between the trasmission time and the received echo from the ionospheric layer
(proportional to the altitude) as function of the radio frequency.

23. A SPACE WEATHER EVENT DETECTED OVER CYPRUS
foF2 and vTEC variations at Nicosia during 9-15 October 2008

24. SOLAR FLARE EVENTS IN 2015

25. The practical significance of the increase in D-region electron density caused by solar flares lies on the
increase of signal absorption that it produces causing limited window of operating frequencies for HF
communications.
QUIET TIME FLARE TIME

26. RESULTS
A SOLAR FLARE EVENT DETECTED OVER CYPRUS

27. ………………………..the nature of ionosphere is highly variable and can
make it difficult to find and maintain a frequency to communicate.
Although ionospheric global models represent a valid tool to plan HF links,
ionospheric regional models can be important to catch some features that may
be easily neglected by global models.
Cyprus Ionospheric Forecasting Service
CYPRUS IONOSPHERIC FORECASTING SERVICE (CIFS)

28. fplot Nicosia station http://ionos.ingv.it/cyprus/fplot.htm
CYPRUS IONOSPHERIC FORECASTING SERVICE (CIFS)

29. foF2 nowcasting maps http://ionos.ingv.it/cyprus/fof2_nowcasting.htm
CYPRUS IONOSPHERIC FORECASTING SERVICE (CIFS)

30. foF2 long-term maps http://ionos.ingv.it/cyprus/fof2_long_term.htm
CYPRUS IONOSPHERIC FORECASTING SERVICE (CIFS)

31. MUF nowcasting maps http://ionos.ingv.it/cyprus/muf_nowcasting.htm
f<12MHz
CYPRUS IONOSPHERIC FORECASTING SERVICE (CIFS)

32. EFFECT OF SPORADIC-E
The presence of a Es layer which does not allow for ionosonde signals to reach F2
region altitudes does not allow a useful ionogram to be obtained and therefore gaps in
the data series of foF2 are formed. These gaps have to be interpolated in a way to
preserve the inherent variability of foF2 data.
0
2
4
6
8
4/18/2009 4/19/2009 4/20/2009 4/21/2009
Date
foF2(MHz)
0
2
4
6
8
5/13/2009 5/14/2009 5/15/2009 5/16/2009
Date
foF2(MHz)
No Es
Es

33. EFFECT OF SPORADIC-E LAYER OVER CYPRUS

34. INTERMEDIATE DESCENDING LAYERS OF METEOR ORIGIN OVER CYPRUS
Height,kmHeight,km
Nicosia Feb. 26 – Mar 19, 2009
Nicosia Feb. 26 – Mar 19, 2010

35. MODELING OF INTERMEDIATE DESCENDING LAYERS

37. THE CYPRUS DIGITAL IONOSONDE CONTRIBUTES TO GLOBAL MODELING

38. TOPSIDE INVESTIGATION OVER CYPRUS
The ionosonde can only probe up to the F2peak. Therefore to investigate the
topside ionosphere over Cyprus we used satellite data.

39. g LEO
GPS Sat.
GPS Sat.10sec data
sec data
GPS sounding of the Ionosphere onboard CHAMP
GPS Satellite
CHAMP
CHAMP Orbit
Radio Signal
Occulting LEO
Occulting GPS
Ground
receiver
1-sec
data
(LINK
4)
20
m
sec
data
(LINK
2)
1-secdata(LINK
3)
20 msecdata
Ionosphere
Neutral atmosphere
Earth
(LINK 1)
GPS Sat.
GPS Sat.
GPS Sat.10sec data
10sec data
10secdata
Occulting LEOGround
receiver
1-sec
data
(LINK
4)
a
(LINK
2)
20 msecdata
Ionosphere
Neutral atmosphere
Earth
(LINK 1)
GPS Sat.10sec data
10
sec data
10se

40. COSMIC vs ionosonde peak characteristics over Cyprus
0
4
8
12
0 4 8 12
Nicosia foF2 (MHz)
COSMICfoF2(MHz)
R=0.96
160
220
280
340
160 220 280 340
Nicosia hmF2 (km)
COSMIChmF2(km)
R=0.87

41. Area considered with positions of one week of RO electron density
measurements and location of Cyprus ionosonde station.
RADIO OCCULTATION MEASUREMENTS

42. COSMIC VS IONOSONDE PEAK IONOSPHERIC
CHARACTERISTICS OVER CYPRUS

43. COSMIC VS IONOSONDE TOPSIDE PROFILE COMPARISON OVER CYPRUS

44. ELECTRON DENSITY PROFILE MODELS OVER CYPRUS

45. GPS system
• The GPS constellation is constituted by a
network of 24 satellites orbiting at 20,200
km from the Earth surface. They are evenly
distributed within 6 orbitals planes inclined
55 with respect to the Earth’s equator and
equally spaced at 60. Each satellite has a
period of 12 hours.
• GPS satellites transmit two simultaneous
PRN signals whose carrier frequencies are
1575.42 MHz and 1227.60 MHz,
respectively. GPS receivers record these
signals as Pseudo Range and Relative
Phase.

46. Civilian GPS Applications Potentially Impacted

47. MEASUREMENT OF TEC BY SPECIAL GPS RECEIVERS
Dual-frequency GPS data recorded by GPS receivers enable an estimation of
ionospheric variability because of the frequency dependent delay imposed on the
signal due to the ionosphere. By processing code and phase measurements on two
frequencies in the L-band ( L1=1575.42 MHz, L2=1227.60 MHz) it is possible to
extract an estimate of the Total Electron Content (TEC) measured in total electron
content units.
TEC
cf
tion 2
3.40


2
1
).(
h
h
dhhNTEC

48. CYPRUS DGPS STATION

49. GPS+ IGS: Global Iono. scanner
GPS+ IGS
Worldwide scanner of the Ionosphere which allow to
generate global VTEC maps from ~30 GPS dual-freq.
transmitters and 300+ global GPS permanent receivers
(50,000+ STECs each 30 seconds).

51. GUIDANCE APPLICATIONS

52. IONOSPHERIC IMPACT ON NAVIGATION AND POSITIONING
Complex temporal and spatial changes within the Earth's ionosphere can limit and degrade
the performance of earth to satellite systems. Communication systems involving trans-
ionospheric propagation may be disrupted; global positioning networks compromised and
surveillance (both optical and radar based) systems affected.

53. NEQUICK ASSESSMENT OVER CYPRUS

54. NEQUICK ASSESSMENT OVER CYPRUS
• To compare NeQuick with of vTEC (vertical TEC) over Cyprus through a high (2001) and
low (2008) solar activity periods we present a representative month of Fall (September).
GPS TEC was derived for each hour and subsequently the median, the lower and upper
deciles were computed to reveal the variability. It is evident that NeQuick
underestimates vTEC during high solar activity especially around midday and
overestimates at low solar activity.
September 2008
0
5
10
15
20
0 6 12 18 24
UT
vTEC(TECU)
September 2001
0
10
20
30
40
50
60
70
80
0 6 12 18 24
UT
vTEC(TECU)
Lower decile
Median
Upper decile
NeQuick

55. SATELLITE-BASED AUGMENTATION SYSTEM (SBAS)

56. SATELLITE-BASED AUGMENTATION SYSTEM (SBAS)

57. EGNOS (THE EUROPEAN GEOSTATIONARY NAVIGATION OVERLAY SERVICE) TYPICA
PERFORMANCE

58. Diffractive and refractive
processes from irregular
electron density structure
Causes phase jitter and
amplitude fading – called
scintillation
What is scintillation and why is it important?

59. Scintillation is important
because it disrupts
satellite-ground
communications and
navigation systems
Particular of interest to
GPS users with safety-
critical applications

60. IONOSPHERIC INSTABILITIES PRODUCE SCINTILLATIONS

61. Ionospheric impact on navigation and
positioning
• Ionospheric perturbations will also impact
GALILEO
Ionospheric gradients Ionospheric scintillations
GPS/GALILEO
TECV
Ionospheric
irregularities
Reference
station
User
User
Phase errors
Misleading
Corrections
DGPS Single point user
Signal strength fluctuations
availability and safety reduced
Motion of gradients
v
Dual frequency measurements
enable estimating the
Total Electron Content (TEC)
dsnTEC e
s
ne
1st order
ionospheric
range error
Is ~ TEC

62. SCINTILATION IMPACT ON NAVIGATION AND POSITIONING

63. TEMPORALAND SPATIAL CHARACERISTICS OF SCINTILLATIONS

64. CYPRUS SCINTILLATION MONITOR
The scintillation receiver takes 50 GPS measurements per second, and performs statistical analysis on
these measurements. These statistics are shown below. The S4 index is a measure of amplitude
scintillation, that is rapid variation in the apparent signal strength. Sigma phi is a measure of phase
scintillation, that is (roughly speaking) rapid oscillation in the delay between the signal leaving the
satellite and arriving at the receiver.

65. IONOSPHERIC SCINTILLATIONS OVER CYPRUS

66. IONOSPHERIC SCINTILLATIONS OVER CYPRUS

67. IONOSPHERIC SCINTILLATIONS OVER CYPRUS

69. VLF TRANSMITTERS

70. US Navy VLF transmitter, at Lualualei, Hawaii. This transmitter has
radiated power of ~500 kW operating at frequency of 21.4 kHz. The towers
in the background are ~460 meters high each.

71. CYPRUS VLF (AWESOME) STATION
A VLF station has been in operation in the last four years to initiate VLF studies in Cyprus.
It is based on the Atmospheric Weather Electromagnetic System for Observation, Modeling,
and Education (AWESOME), a research-quality monitor developed by Stanford University.
It facilitates the study of several space weather related phenomena like solar flares

72. VLF MONITORING OVER CYPRUS

74. STORM MONITORING USING VLF

75. IONOSPHERIC TOMOGRAPHY OVER CYPRUS

76. IONOSPHERIC TOMOGRAPHY OVER CYPRUS

77. MORE RECEIVERS =HIGHER TOMOGRAPHIC RESOLUTION

78. TOHOKU EARTHQUAKE AND TSUNAMI IN IONOSPHERE

79. Data and methodology - Seismic eventsSeismic events
No of Earthq Mw Date time (UT) R (km) Lat (°) Lon (°) Depth
(Km)
Region
E1 7.2 11/12/1999 16:57 1247 40.78 31.21 10 western Turkey
E2 6.9 02/14/2008 10:09 927 36.50 21.67 29 southern Greece
E3 6.5 02/14/2008 12:08 624 36.35 21.86 28 southern Greece
E4 6.4 06/08/2008 12:25 565 37.96 21.53 16 southern Greece
E5 6.3 04/06/2009 1:32 512 42.33 13.33 8.8 central Italy
E6 6.2 06/15/2013 16:11 463 34.45 25.04 10 Crete, Greece
E7 6.2 01/06/2008 5:14 463 37.22 22.69 75 southern Greece
E8 6.0 04/01/2011 13:29 380 35.66 26.56 59.9 Crete, Greece
E9 6.5 11/17/2015 07:10 624 38.6 20.6 11 Lefkada, Greece
E10 6.9 05/24/2014 9:25 927 40.29 25.39 6.43 N. Aegean Sea, Greece
E11 6.1 16-04-2015 18:07 420 34.99 26.98 6.33 Crete Istand
E12 5.6 15-04-2015 08:25 256 34.82 08:25 27.62 Cyprus
EUROPE
Cyprus
Greece
Italy
Turkey
The preparation
area is the area
where the
ionosphere above it
is affected by
earthquake
precursors and is
defined as a circle
with radius ρ=100.43Μ
km

80. Data and methodology - Seismic eventsSeismic events
Strong
earthquakes
(M>7.5)
in 2015
Nepal M7.8 Chile M8.3
Peru M7.6Afghanistan M7.5

81. Chile M8.3 earthquake
on 16 September 2015

82. Data and methodology - Seismic events1. Statistical envelope method
Diurnal TEC variations (red solid line), corresponding upper (blue dotted line) and lower bounds (green dotted line) fixed at μ±1.34σ and mean TEC variations
μ (black solid line) are depicted for 4 GPS stations for 13 days before, during and 1 day after the Chile seismic event at 16th September 2015. Blue shaded
areas show the geomagnetically disturbed periods and blue vertical line shows the earthquake main shock. Plots for each GPS station are ordered by their
distance from the epicenter. The first three stations are located inside and the last outside the earthquake preparation zone. Diurnal variations of Dst
geomagnetic index is also shown (upper panel).

83. 2. Spectral analysis
Fluctuations of
differential TEC (T=40m
period ) obtained from
measurements of 6
satellites (PRN) passing
over the area of interest
during 15-18 UT at the
day of earthquake
(16th Sep. 2015). The
power spectrographs of
the amplitude are also
shown. Map shows the
number and position of
satellites IPP (blue
asterisks), the position
of the GPS receiver
station SANT (pink
triangle) and the
earthquake epicenter
(green asterisk)
Inspection of all spectrograms revealed persistent enhanced amplitude TEC fluctuations on 7, 11, 14, 15
September and the day of earthquake 16 September, starting at around 13UT and lasting for approximately 8
hours (up to 21 UT), deriving from SANT and CORD receivers measurements which are located near the
epicenter. These TEC oscillations are mainly periodic with a period around 20 min. Their time of appearance
demonstrates regularity centered at approximately 1300-2100 UT.

84. Thank you for your attention!!!