This document discusses the ionosphere and its effects on radio systems. It begins with an introduction to the ionosphere, its layers, and how it can reflect radio signals. It then discusses space weather events like solar flares and coronal mass ejections that impact the ionosphere. The document outlines ionospheric monitoring efforts in Cyprus using instruments like ionosondes and GPS receivers. It presents results on topics like modeling the ionosphere, detecting scintillations, and using radio occultations to study the topside ionosphere. The document emphasizes how understanding the ionosphere is important for radio communications and navigation systems.
With the adoption in April and the launch of S1A, the European Programme for Earth Observation, Copernicus, will deliver European information services based on satellite Earth Observation and in-situ data analyses. It is the first time that vast amounts of global data from satellites and from ground-based, airborne and seaborne measurement systems are being used to provide information to help service providers, public authorities and other international organisations improve the quality of life for the citizens of Europe. The information services provided will be freely and openly accessible to users.
The services address six thematic areas: land, marine, atmosphere, climate change, emergency management and security.
Copernicus Services support a broad range of environmental and security applications, including sustainable development, transport and mobility, climate change monitoring, civil protection, urban area management, regional and local planning, agriculture and health.
The wealth of space based data is an important opportunity to develop innovative space applications. Copernicus Services will have to evolve to remain in tune with the state-of-art, adjusting to user's requirement and new developments need. Thanks to H2020, the Europe's research Programme, this will be guaranteed.
UK Spectrum Policy Forum - Daniela Genta, Airbus Group - Earth Observation an...techUK
UK Spectrum Policy Forum
Daniela Genta, VP Radio Regulatory Affairs and Policy, Airbus Group
Earth Observation and Science: Use of Spectrum Today and Tomorrow, in the UK and Worldwide
See more at: http://www.techuk.org/about/uk-spectrum-policy-forum
All Rights Reserved
The Hungarian Association for Geo-information (HUNAGI) and the Remote Sensing as Space Application.
Invited talk at the ceremony of Signing the Accession Agreement of Hungary to the European Space Agency (ESA) on 24 february 2015.
With the adoption in April and the launch of S1A, the European Programme for Earth Observation, Copernicus, will deliver European information services based on satellite Earth Observation and in-situ data analyses. It is the first time that vast amounts of global data from satellites and from ground-based, airborne and seaborne measurement systems are being used to provide information to help service providers, public authorities and other international organisations improve the quality of life for the citizens of Europe. The information services provided will be freely and openly accessible to users.
The services address six thematic areas: land, marine, atmosphere, climate change, emergency management and security.
Copernicus Services support a broad range of environmental and security applications, including sustainable development, transport and mobility, climate change monitoring, civil protection, urban area management, regional and local planning, agriculture and health.
The wealth of space based data is an important opportunity to develop innovative space applications. Copernicus Services will have to evolve to remain in tune with the state-of-art, adjusting to user's requirement and new developments need. Thanks to H2020, the Europe's research Programme, this will be guaranteed.
UK Spectrum Policy Forum - Daniela Genta, Airbus Group - Earth Observation an...techUK
UK Spectrum Policy Forum
Daniela Genta, VP Radio Regulatory Affairs and Policy, Airbus Group
Earth Observation and Science: Use of Spectrum Today and Tomorrow, in the UK and Worldwide
See more at: http://www.techuk.org/about/uk-spectrum-policy-forum
All Rights Reserved
The Hungarian Association for Geo-information (HUNAGI) and the Remote Sensing as Space Application.
Invited talk at the ceremony of Signing the Accession Agreement of Hungary to the European Space Agency (ESA) on 24 february 2015.
This is the scrolling slide set used throughout the 4 gala dinners that were held in Crystal City (USA), Geneva (Switzerland), Calgary (Canada) and Tokyo (Japan)
Greetings all,
This month’s newsletter is devoted to Oceanic biogeochemistry.
Le Traon is introducing this newsletter telling us about Argo- the single most important in-situ observing system for operational
oceanography- and Euro-Argo which is aiming at maintaining the array’s size and global coverage in the coming decades in order
to develop and progressively consolidate the European component of the global network.
Scientific articles about Oceanic biogeochemistry are then displayed as follows: D'Ortenzio et al. are writing about the PABIM
project (Biogeochemical Autonomous Platforms: Instrumentation and Measures) which aims at developing and exploiting
biogeochemical observations obtained from autonomous platforms (gliders, profiling floats, animals). Lévy et al. are then telling us
about the remote impacts of sub-mesoscale dynamics on new production with a net new production that decreases by 10% at
higher resolution, with regional differences reaching +/- 30%. Lefèvre et al. are then explaining about autonomous CO2
measurements in the tropical Atlantic Ocean with an observational CO2 network that has been set up to better document the
variability of the fugacity of CO2 (fCO2) in the Atlantic ocean, to determine its long term trend, and to provide accurate estimates of
the air-sea CO2 flux. Finally, Lehodey et al. with the “Mercator-Vert” project are working on a prototype of coupled physical/
biogeochemical model with the objective to routinely estimate and forecast the biogeochemical variables of the global ocean.
Such operational models should provide in a near future the necessary inputs for ecosystem models of the upper trophic levels,
allowing the development of new tools and products for a real-time management and monitoring of marine ecosystems and
resources.
The next January 2010 newsletter will review the current work on Data Assimilation and its application for Ocean reanalyses. We
wish you a pleasant reading.
Big Data from Space outreach presentation describing the "Bring User to Data Scenario" and the Research and Service Support provided for scientific users, research centres, small and medium size enterprises, industry and institutions.
Use of Unmanned Aerial Systems for Hydrological MonitoringSalvatore Manfreda
Invited presentation given during the EGU General Assembly at the session entitled "Advances in river monitoring and modelling: data-scarce environments, real-time approaches, Inter-comparison of innovative and classical frameworks, uncertainties, Harmonisation of methods and good practices"
Did you know that you use space technology every day? And that stellar space know-how comes from Finland? We got microsatellite-data based maritime and forestry services plus hardcore space components and much more. See for yourself.
https://www.businessfinland.fi/en
http://spacefinland.fi/
This is the scrolling slide set used throughout the 4 gala dinners that were held in Crystal City (USA), Geneva (Switzerland), Calgary (Canada) and Tokyo (Japan)
Greetings all,
This month’s newsletter is devoted to Oceanic biogeochemistry.
Le Traon is introducing this newsletter telling us about Argo- the single most important in-situ observing system for operational
oceanography- and Euro-Argo which is aiming at maintaining the array’s size and global coverage in the coming decades in order
to develop and progressively consolidate the European component of the global network.
Scientific articles about Oceanic biogeochemistry are then displayed as follows: D'Ortenzio et al. are writing about the PABIM
project (Biogeochemical Autonomous Platforms: Instrumentation and Measures) which aims at developing and exploiting
biogeochemical observations obtained from autonomous platforms (gliders, profiling floats, animals). Lévy et al. are then telling us
about the remote impacts of sub-mesoscale dynamics on new production with a net new production that decreases by 10% at
higher resolution, with regional differences reaching +/- 30%. Lefèvre et al. are then explaining about autonomous CO2
measurements in the tropical Atlantic Ocean with an observational CO2 network that has been set up to better document the
variability of the fugacity of CO2 (fCO2) in the Atlantic ocean, to determine its long term trend, and to provide accurate estimates of
the air-sea CO2 flux. Finally, Lehodey et al. with the “Mercator-Vert” project are working on a prototype of coupled physical/
biogeochemical model with the objective to routinely estimate and forecast the biogeochemical variables of the global ocean.
Such operational models should provide in a near future the necessary inputs for ecosystem models of the upper trophic levels,
allowing the development of new tools and products for a real-time management and monitoring of marine ecosystems and
resources.
The next January 2010 newsletter will review the current work on Data Assimilation and its application for Ocean reanalyses. We
wish you a pleasant reading.
Big Data from Space outreach presentation describing the "Bring User to Data Scenario" and the Research and Service Support provided for scientific users, research centres, small and medium size enterprises, industry and institutions.
Use of Unmanned Aerial Systems for Hydrological MonitoringSalvatore Manfreda
Invited presentation given during the EGU General Assembly at the session entitled "Advances in river monitoring and modelling: data-scarce environments, real-time approaches, Inter-comparison of innovative and classical frameworks, uncertainties, Harmonisation of methods and good practices"
Did you know that you use space technology every day? And that stellar space know-how comes from Finland? We got microsatellite-data based maritime and forestry services plus hardcore space components and much more. See for yourself.
https://www.businessfinland.fi/en
http://spacefinland.fi/
Ionospheric Behaviour Analysis over Thailand Using Radio Occultation TechniqueIJERA Editor
With the advent in the development of science and technology in the field of space and atmospheric science in
order to obtain accurate result, hence the use of radio occultation technique in the investigation of the amount of
electron density and Total Electron Content presence in equatorial region particularly over Thailand. In this
research, radio occultation data obtained from UCAR/CDAAC was used to observe daily, monthly, seasonal and
the entire year 2013 Ionospheric TEC and electron density variation due to changes and instability of solar
activities from time to time. It was observed that TEC was high (ionosphere was more disturbed or violent) in
May and spread over a wide range of altitude and summer season has the highest TEC value for the year 2013
which means at this period GNSS measurements was more prone to error. It was noted that ionospheric
variations or fluctuations was maximum between 200km and 450km altitude. The results of the study show that
ionospheric perturbation effects or irregularities depend on season and solar activity.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Convective storms in Europe: a look back at COPS and CSIPAndrew Russell
A seminar given at RMS in London on 16th March on the main results from the Convective Storm Initiation Project (CSIP) and the Convective and Orographically-induced Precipitation Study (COPS).
APPLICATION OF REMOTE SENSING AND GIS IN AGRICULTURELagnajeetRoy
India is a country that depends on agriculture. Today in this era of technological supremacy, agriculture is also using different new technologies like some robotic machinery to remote sensing and Geographical Information System (GIS) for the betterment of agriculture. It is easy to get the information about that area where human cannot check the condition everyday and help in gathering the data with the help of remote sensing. Whereas GIS helps in preparation of map that shows an accurate representation of data we get through remote sensing. From disease estimation to stress factor due to water, from ground water quality index to acreage estimation in various way agriculture is being profited by the application of remote sensing and GIS in agriculture. The applications of those software or techniques are very new to the agriculture domain still much more exploration is needed in this part. New software’s are developing in different parts of the world and remote sensing. Today farmers understand the beneficiaries of these kinds of techniques to the farm field which help in increasing productivity that will help future generation as technology is hype in traditional system of farming.
Acoustic and seismic effects of the 2013 Chelyabinsk meteorite as measured by...Ivan Kitov
Two events crucial for monitoring of nuclear explosions under the CTBT occurred on February 12 and 15 and attracted attention of the mass media and scientists. Seismic waves from the underground event and infrasound waves from the meteorite are of extreme interest as well as various processes of energy conversion at the free surface. Infrasound station I45(RU) collocated with seismic array USRK recorded the epicentral I-phase generated by the DPRK 2013 event and the seismoacoustic wave emitted beneath the station. The shock wave from the Chebarkul meteorite generated a regular I-phase recorded by many IMS infrasound stations and a series of seismic phases likely associated with impact and acoustoseismic conversion. Due to the altitude of the peak energy release, the air-coupled ground rolls with a group velocity of 3.5 km/s were generated. A similar pattern was observed after the 1984 r.Chulym (Siberia) bolide. We estimate the energy of both sources and discuss possible mechanisms of acoustic/seismic wave generation and conversion.
Theodoros Xanthos MD, Pg Dip (Ed), MSc, MRes (EdD), PhD, FHEA, FAcadMEd, FCP, FERC, ERT, FESC
Professor of Medicine European University Cyprus
ERC Medical Educator Trainer (Europe)
President Hellenic Society of Cardiopulmonary Resuscitation
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
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
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.
13. MULTIPLE DAY SPACE WEATHER EVENT BY SOHO
(Solar and Heliospheric Observatory)
14.
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.
16.
17.
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 )
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
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
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)
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
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
41. Area considered with positions of one week of RO electron density
measurements and location of Cyprus ionosonde station.
RADIO OCCULTATION MEASUREMENTS
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.
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
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).
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.
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
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
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
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.
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
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.