{"id":{"repo_id":"greece","oai_identifier":"oai:10442/0748"},"canonical_url":"https://search.dev.ndltd.org/etd/greece/oai:10442/0748","repository":{"repo_id":"greece","name":"Greek National Archive of PhD Theses","base_url":"https://phdtheses.ekt.gr/eadd_oai/request"},"display":{"title":"ΒΡΑΔΥΝΗ ΔΙΙΣΗΜΕΡΙΝΗ ΔΙΑΔΟΣΗ ΠΟΛΥ ΥΨΗΛΩΝ ΡΑΔΙΟΣΥΧΝΟΤΗΤΩΝ ΜΕΤΑΞΥ ΕΛΛΑΔΟΣ ΚΑΙ ΑΦΡΙΚΗΣ ΓΥΡΩ ΑΠΟ ΤΟ ΜΕΓΙΣΤΟ ΤΟΥ 21ΟΥ ΗΛΙΑΚΟΥ ΚΥΚΛΟΥ (1978-1982)","abstract":"A HISTORIC AND BIBLIOGRAPHIC REVIEW IS MADE RELATING AFTERNOON AND EVENING TYPETRANSEQUATORIAL PROPAGATION (TEP) WITH SPECIAL IONOSPHERIC PHENOMENA PRESENT IN THE EQUATORIAL ZONE. THE PARTICULARITIES OF THE EURO-AFRICAN TEP SECTOR ARE STATED TOGETHER WITH THE RESEARCH WORK CARRIED OUT DURING PAST TWO AND LAST SOLAR CYCLES. THE RESULTS OF OBSERVATIONS AND MEASUREMENTS ARE GIVEN EXAMINING TEP IN RELATION WITH DIFFERENT FACTORS SUCH AS: GEOGRAPHICAL POSITION, DAILY AND SEASONAL VARIATIONS, SOLAR AND MAGNETIC ACTIVITY, SIGNAL STRENGTH AND POLARIZATION OF WAVES, ARRIVAL ANGLES, FREQUENCY SHIFT AND SPREADING, PROPAGATION DELAY, MULTIPATH AND FADING. THE DETAILED DESCRIPTION OF THE TEP TERMINAL STATIONS IS ALSO GIVEN. A THEORETICAL MODEL IS PRESENTED WHICH IS BASED ON THE WAVEGUIDING OF SIGNAL THROUGH DEPLETION DENSITY MAGNETIC FIELD AUGNEG IRREGULARITIES, FORMEDAFTER SUNSET IN THE EQUATORIAL IONOSPHERE BASED ON THAT MODEL, CALCULATIONS ARE MADE FOR THE TOTAL ATTENUATION, DELAY AND CUTOFF FREQUENCY WHICH SHOW GOOD AGREEMENT WITH MEASURED VALUES.","abstract_html":"A HISTORIC AND BIBLIOGRAPHIC REVIEW IS MADE RELATING AFTERNOON AND EVENING TYPETRANSEQUATORIAL PROPAGATION (TEP) WITH SPECIAL IONOSPHERIC PHENOMENA PRESENT IN THE EQUATORIAL ZONE. THE PARTICULARITIES OF THE EURO-AFRICAN TEP SECTOR ARE STATED TOGETHER WITH THE RESEARCH WORK CARRIED OUT DURING PAST TWO AND LAST SOLAR CYCLES. THE RESULTS OF OBSERVATIONS AND MEASUREMENTS ARE GIVEN EXAMINING TEP IN RELATION WITH DIFFERENT FACTORS SUCH AS: GEOGRAPHICAL POSITION, DAILY AND SEASONAL VARIATIONS, SOLAR AND MAGNETIC ACTIVITY, SIGNAL STRENGTH AND POLARIZATION OF WAVES, ARRIVAL ANGLES, FREQUENCY SHIFT AND SPREADING, PROPAGATION DELAY, MULTIPATH AND FADING. THE DETAILED DESCRIPTION OF THE TEP TERMINAL STATIONS IS ALSO GIVEN. A THEORETICAL MODEL IS PRESENTED WHICH IS BASED ON THE WAVEGUIDING OF SIGNAL THROUGH DEPLETION DENSITY MAGNETIC FIELD AUGNEG IRREGULARITIES, FORMEDAFTER SUNSET IN THE EQUATORIAL IONOSPHERE BASED ON THAT MODEL, CALCULATIONS ARE MADE FOR THE TOTAL ATTENUATION, DELAY AND CUTOFF FREQUENCY WHICH SHOW GOOD AGREEMENT WITH MEASURED VALUES.","abstract_has_math":false,"creators":["Φιμερέλης, Κωνσταντίνος"],"institution":"Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ)","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1986,"date_issued":"1986","date_published":"1986","updated_at":"2026-07-24T02:25:27Z","subjects":["Electromagnetism","Signal processing","TRANSEQUATORIAL PROPAGATION-TEP","WAVEPROPAGATION","ΔΙΑΔΟΣΗ ΚΥΜΑΤΩΝ","ΔΙΙΣΗΜΕΡΙΝΗ ΔΙΑΔΟΣΗ","Επεξεργασία σημάτων","Ηλεκτρομαγνητισμός","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ"],"languages":["gre"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/0748"],"render_values":[{"text":"10.12681/eadd/0748","href":"https://doi.org/10.12681/eadd/0748","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10442/hedi/0748","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Φιμερέλης, Κωνσταντίνος"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1986"]},{"key":"dc:publisher","label":"Institution","values":["Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ)","National Technical University of Athens (NTUA)"]},{"key":"dc:type","label":"Dc Type","values":["PhD Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Electromagnetism","Signal processing","TRANSEQUATORIAL PROPAGATION-TEP","WAVEPROPAGATION","ΔΙΑΔΟΣΗ ΚΥΜΑΤΩΝ","ΔΙΙΣΗΜΕΡΙΝΗ ΔΙΑΔΟΣΗ","Επεξεργασία σημάτων","Ηλεκτρομαγνητισμός","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["gre"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/0748","http://hdl.handle.net/10442/hedi/0748"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["A HISTORIC AND BIBLIOGRAPHIC REVIEW IS MADE RELATING AFTERNOON AND EVENING TYPETRANSEQUATORIAL PROPAGATION (TEP) WITH SPECIAL IONOSPHERIC PHENOMENA PRESENT IN THE EQUATORIAL ZONE. THE PARTICULARITIES OF THE EURO-AFRICAN TEP SECTOR ARE STATED TOGETHER WITH THE RESEARCH WORK CARRIED OUT DURING PAST TWO AND LAST SOLAR CYCLES. THE RESULTS OF OBSERVATIONS AND MEASUREMENTS ARE GIVEN EXAMINING TEP IN RELATION WITH DIFFERENT FACTORS SUCH AS: GEOGRAPHICAL POSITION, DAILY AND SEASONAL VARIATIONS, SOLAR AND MAGNETIC ACTIVITY, SIGNAL STRENGTH AND POLARIZATION OF WAVES, ARRIVAL ANGLES, FREQUENCY SHIFT AND SPREADING, PROPAGATION DELAY, MULTIPATH AND FADING. THE DETAILED DESCRIPTION OF THE TEP TERMINAL STATIONS IS ALSO GIVEN. A THEORETICAL MODEL IS PRESENTED WHICH IS BASED ON THE WAVEGUIDING OF SIGNAL THROUGH DEPLETION DENSITY MAGNETIC FIELD AUGNEG IRREGULARITIES, FORMEDAFTER SUNSET IN THE EQUATORIAL IONOSPHERE BASED ON THAT MODEL, CALCULATIONS ARE MADE FOR THE TOTAL ATTENUATION, DELAY AND CUTOFF FREQUENCY WHICH SHOW GOOD AGREEMENT WITH MEASURED VALUES.","ΜΕΤΑ ΑΠΟ ΜΙΑ ΓΕΝΙΚΗ ΙΣΤΟΡΙΚΗ ΑΝΔΡΟΜΗ ΚΑΙ ΠΕΡΙΓΡΑΦΗ ΤΟΥ ΑΠΟΓΕΥΜΑΤΙΝΟΥ ΚΑΙ ΒΡΑΔΥΝΟΥ ΤΥΠΟΥ ΔΙΙΣΗΜΕΡΙΝΗΣ ΔΙΑΔΟΣΗΣ ΚΑΘΩΣ ΚΑΙ ΤΩΝ ΕΙΔΙΚΩΝ ΙΟΝΟΣΦΑΙΡΙΚΩΝ ΦΑΙΝΟΜΕΝΩΝ ΤΗΣ ΙΣΗΜΕΡΙΝΗΣ ΖΩΝΗΣ ΔΙΔΕΤΑΙ Η ΙΔΙΟΜΟΡΦΙΑ ΤΟΥ ΕΥΡΩΑΦΡΙΚΑΝΙΚΟΥ ΤΟΜΕΑ ΚΑΙ Η ΕΡΕΥΝΗΤΙΚΗ ΔΡΑΣΤΗΡΙΟΤΗΤΑ ΣΤΟΝ ΤΟΜΕΑ ΑΥΤΟ ΣΤΗ ΔΙΑΡΚΕΙΑ ΤΩΝ ΔΥΟ ΠΡΟΗΓΟΥΜΕΝΩΝ ΗΛΙΑΚΩΝ ΚΥΚΛΩΝ. ΣΤΗ ΣΥΝΕΧΕΙΑ ΑΝΑΛΥΕΤΑΙ Ο ΤΡΟΠΟΣ ΜΕΛΕΤΗΣ ΤΗΣ ΒΡΑΔΥΝΗΣ ΔΙΙΣΗΜΕΡΙΝΗΣ ΔΙΑΔΟΣΗΣ, ΚΥΡΙΩΣ ΤΗΣ ΜΕΤΡΗΣΗΣ ΔΙΑΣΠΟΡΑΣ ΚΑΙ ΜΕΤΑΤΟΠΗΣΗ ΣΥΧΝΟΤΗΤΑΣ ΚΑΙ ΧΡΟΝΟΥ ΜΟΝΟΦΟΡΗΣΔΙΑΔΟΣΗΣ ΠΑΛΜΩΝ. ΤΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΤΩΝ ΠΑΡΑΤΗΡΗΣΕΩΝ ΚΑΙ ΜΕΤΡΗΣΕΩΝ ΑΝΑΦΕΡΟΝΤΑΙ ΣΤΗ: ΓΕΩΓΡΑΦΙΚΗ ΕΞΑΡΤΗΣΗ, ΗΜΕΡΗΣΙΕΣ ΚΑΙ ΕΠΟΧΙΑΚΕΣ ΜΕΤΑΒΟΛΕΣ, ΑΞΙΟΠΙΣΤΙΑ ΤΩΝ ΖΕΥΞΕΩΝ, ΗΛΙΑΚΗ ΚΑΙ ΜΑΓΝΗΤΙΚΗ ΕΞΑΡΤΗΣΗ, ΕΝΤΑΣΗ ΚΑΙ ΠΟΛΩΣΗ ΤΩΝ ΣΗΜΑΤΩΝ, ΓΩΜΕΣ ΑΦΙΞΗΣ ΚΑΙ ΤΗ ΜΕΤΑΒΟΛΗ ΤΟΥΣ, ΔΙΑΣΠΟΡΑ ΚΑΙ ΜΕΤΑΤΟΠΗΣΗ ΣΥΧΝΟΤΗΤΑΣ, ΧΡΟΝΟ ΔΙΑΔΟΣΗΣ ΠΑΛΜΩΝ, ΠΟΛΛΑΠΛΗ ΔΙΑΔΟΣΗ ΚΑΙ ΔΙΑΛΗΨΕΙΣ, ΟΜΟΙΟΤΗΤΕΣ ΑΝΑΜΕΣΑ ΣΤΟΥΣ ΔΙΙΣΗΜΕΡΙΝΟΥΣ ΤΟΜΕΙΣΤΗΣ ΓΗΣ. ΜΕ ΒΑΣΗ ΤΗΝ ΚΥΜΑΤΟΔΗΓΗΣΗ ΤΩΝ ΡΑΔΙΟΚΥΜΑΤΩΝ ΜΕΣΑ ΑΠΟ ΠΡΟΣΑΝΑΤΟΛΙΣΜΕΝΕΣ ΣΤΟ ΓΗΙΝΟ ΜΑΓΝΗΤΙΚΟ ΠΕΔΙΟ ΑΝΟΜΟΙΟΓΕΝΕΙΕΣ ΚΕΝΩΝ ΙΟΝΙΣΜΟΥ ΣΑΝ ΜΟΝΤΕΛΟ ΔΙΑΔΟΣΗΣ ΣΥΓΚΡΙΝΟΝΤΑΙ ΤΑ ΘΕΩΡΗΤΙΚΑ ΜΕ ΤΑ ΠΕΙΡΑΜΑΤΙΚΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΠΟΥ ΣΥΜΠΙΠΤΟΥΝ ΙΚΑΝΟΠΟΙΗΤΙΚΑ ΚΑΙ ΕΞΗΓΟΥΝΤΑΙ ΟΙ ΑΠΟΚΛΙΣΕΙΣ ΠΟΥ ΕΜΦΑΝΙΖΟΝΤΑΙ."]},{"key":"dc:title","label":"Title","values":["ΒΡΑΔΥΝΗ ΔΙΙΣΗΜΕΡΙΝΗ ΔΙΑΔΟΣΗ ΠΟΛΥ ΥΨΗΛΩΝ ΡΑΔΙΟΣΥΧΝΟΤΗΤΩΝ ΜΕΤΑΞΥ ΕΛΛΑΔΟΣ ΚΑΙ ΑΦΡΙΚΗΣ ΓΥΡΩ ΑΠΟ ΤΟ ΜΕΓΙΣΤΟ ΤΟΥ 21ΟΥ ΗΛΙΑΚΟΥ ΚΥΚΛΟΥ (1978-1982)","EVENING-TYPE TRANSEQUATORIAL VHF PROPAGATION BETWEEN GREECE AND AFRICA DURING THE PEAK OF SOLAR CYCLE 21 (1978-1982)"]}]}],"canonical_facts":{"dc:creator":["Φιμερέλης, Κωνσταντίνος"],"dc:date":["1986"],"dc:description":["A HISTORIC AND BIBLIOGRAPHIC REVIEW IS MADE RELATING AFTERNOON AND EVENING TYPETRANSEQUATORIAL PROPAGATION (TEP) WITH SPECIAL IONOSPHERIC PHENOMENA PRESENT IN THE EQUATORIAL ZONE. THE PARTICULARITIES OF THE EURO-AFRICAN TEP SECTOR ARE STATED TOGETHER WITH THE RESEARCH WORK CARRIED OUT DURING PAST TWO AND LAST SOLAR CYCLES. THE RESULTS OF OBSERVATIONS AND MEASUREMENTS ARE GIVEN EXAMINING TEP IN RELATION WITH DIFFERENT FACTORS SUCH AS: GEOGRAPHICAL POSITION, DAILY AND SEASONAL VARIATIONS, SOLAR AND MAGNETIC ACTIVITY, SIGNAL STRENGTH AND POLARIZATION OF WAVES, ARRIVAL ANGLES, FREQUENCY SHIFT AND SPREADING, PROPAGATION DELAY, MULTIPATH AND FADING. THE DETAILED DESCRIPTION OF THE TEP TERMINAL STATIONS IS ALSO GIVEN. A THEORETICAL MODEL IS PRESENTED WHICH IS BASED ON THE WAVEGUIDING OF SIGNAL THROUGH DEPLETION DENSITY MAGNETIC FIELD AUGNEG IRREGULARITIES, FORMEDAFTER SUNSET IN THE EQUATORIAL IONOSPHERE BASED ON THAT MODEL, CALCULATIONS ARE MADE FOR THE TOTAL ATTENUATION, DELAY AND CUTOFF FREQUENCY WHICH SHOW GOOD AGREEMENT WITH MEASURED VALUES.","ΜΕΤΑ ΑΠΟ ΜΙΑ ΓΕΝΙΚΗ ΙΣΤΟΡΙΚΗ ΑΝΔΡΟΜΗ ΚΑΙ ΠΕΡΙΓΡΑΦΗ ΤΟΥ ΑΠΟΓΕΥΜΑΤΙΝΟΥ ΚΑΙ ΒΡΑΔΥΝΟΥ ΤΥΠΟΥ ΔΙΙΣΗΜΕΡΙΝΗΣ ΔΙΑΔΟΣΗΣ ΚΑΘΩΣ ΚΑΙ ΤΩΝ ΕΙΔΙΚΩΝ ΙΟΝΟΣΦΑΙΡΙΚΩΝ ΦΑΙΝΟΜΕΝΩΝ ΤΗΣ ΙΣΗΜΕΡΙΝΗΣ ΖΩΝΗΣ ΔΙΔΕΤΑΙ Η ΙΔΙΟΜΟΡΦΙΑ ΤΟΥ ΕΥΡΩΑΦΡΙΚΑΝΙΚΟΥ ΤΟΜΕΑ ΚΑΙ Η ΕΡΕΥΝΗΤΙΚΗ ΔΡΑΣΤΗΡΙΟΤΗΤΑ ΣΤΟΝ ΤΟΜΕΑ ΑΥΤΟ ΣΤΗ ΔΙΑΡΚΕΙΑ ΤΩΝ ΔΥΟ ΠΡΟΗΓΟΥΜΕΝΩΝ ΗΛΙΑΚΩΝ ΚΥΚΛΩΝ. ΣΤΗ ΣΥΝΕΧΕΙΑ ΑΝΑΛΥΕΤΑΙ Ο ΤΡΟΠΟΣ ΜΕΛΕΤΗΣ ΤΗΣ ΒΡΑΔΥΝΗΣ ΔΙΙΣΗΜΕΡΙΝΗΣ ΔΙΑΔΟΣΗΣ, ΚΥΡΙΩΣ ΤΗΣ ΜΕΤΡΗΣΗΣ ΔΙΑΣΠΟΡΑΣ ΚΑΙ ΜΕΤΑΤΟΠΗΣΗ ΣΥΧΝΟΤΗΤΑΣ ΚΑΙ ΧΡΟΝΟΥ ΜΟΝΟΦΟΡΗΣΔΙΑΔΟΣΗΣ ΠΑΛΜΩΝ. ΤΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΤΩΝ ΠΑΡΑΤΗΡΗΣΕΩΝ ΚΑΙ ΜΕΤΡΗΣΕΩΝ ΑΝΑΦΕΡΟΝΤΑΙ ΣΤΗ: ΓΕΩΓΡΑΦΙΚΗ ΕΞΑΡΤΗΣΗ, ΗΜΕΡΗΣΙΕΣ ΚΑΙ ΕΠΟΧΙΑΚΕΣ ΜΕΤΑΒΟΛΕΣ, ΑΞΙΟΠΙΣΤΙΑ ΤΩΝ ΖΕΥΞΕΩΝ, ΗΛΙΑΚΗ ΚΑΙ ΜΑΓΝΗΤΙΚΗ ΕΞΑΡΤΗΣΗ, ΕΝΤΑΣΗ ΚΑΙ ΠΟΛΩΣΗ ΤΩΝ ΣΗΜΑΤΩΝ, ΓΩΜΕΣ ΑΦΙΞΗΣ ΚΑΙ ΤΗ ΜΕΤΑΒΟΛΗ ΤΟΥΣ, ΔΙΑΣΠΟΡΑ ΚΑΙ ΜΕΤΑΤΟΠΗΣΗ ΣΥΧΝΟΤΗΤΑΣ, ΧΡΟΝΟ ΔΙΑΔΟΣΗΣ ΠΑΛΜΩΝ, ΠΟΛΛΑΠΛΗ ΔΙΑΔΟΣΗ ΚΑΙ ΔΙΑΛΗΨΕΙΣ, ΟΜΟΙΟΤΗΤΕΣ ΑΝΑΜΕΣΑ ΣΤΟΥΣ ΔΙΙΣΗΜΕΡΙΝΟΥΣ ΤΟΜΕΙΣΤΗΣ ΓΗΣ. ΜΕ ΒΑΣΗ ΤΗΝ ΚΥΜΑΤΟΔΗΓΗΣΗ ΤΩΝ ΡΑΔΙΟΚΥΜΑΤΩΝ ΜΕΣΑ ΑΠΟ ΠΡΟΣΑΝΑΤΟΛΙΣΜΕΝΕΣ ΣΤΟ ΓΗΙΝΟ ΜΑΓΝΗΤΙΚΟ ΠΕΔΙΟ ΑΝΟΜΟΙΟΓΕΝΕΙΕΣ ΚΕΝΩΝ ΙΟΝΙΣΜΟΥ ΣΑΝ ΜΟΝΤΕΛΟ ΔΙΑΔΟΣΗΣ ΣΥΓΚΡΙΝΟΝΤΑΙ ΤΑ ΘΕΩΡΗΤΙΚΑ ΜΕ ΤΑ ΠΕΙΡΑΜΑΤΙΚΑ ΑΠΟΤΕΛΕΣΜΑΤΑ ΠΟΥ ΣΥΜΠΙΠΤΟΥΝ ΙΚΑΝΟΠΟΙΗΤΙΚΑ ΚΑΙ ΕΞΗΓΟΥΝΤΑΙ ΟΙ ΑΠΟΚΛΙΣΕΙΣ ΠΟΥ ΕΜΦΑΝΙΖΟΝΤΑΙ."],"dc:identifier":["10.12681/eadd/0748","http://hdl.handle.net/10442/hedi/0748"],"dc:language":["gre"],"dc:publisher":["Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ)","National Technical University of Athens (NTUA)"],"dc:subject":["Electromagnetism","Signal processing","TRANSEQUATORIAL PROPAGATION-TEP","WAVEPROPAGATION","ΔΙΑΔΟΣΗ ΚΥΜΑΤΩΝ","ΔΙΙΣΗΜΕΡΙΝΗ ΔΙΑΔΟΣΗ","Επεξεργασία σημάτων","Ηλεκτρομαγνητισμός","Engineering and Technology","Electrical Engineering, Electronic Engineering, Information Engineering","Επιστήμες Μηχανικού και Τεχνολογία","Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ"],"dc:title":["ΒΡΑΔΥΝΗ ΔΙΙΣΗΜΕΡΙΝΗ ΔΙΑΔΟΣΗ ΠΟΛΥ ΥΨΗΛΩΝ ΡΑΔΙΟΣΥΧΝΟΤΗΤΩΝ ΜΕΤΑΞΥ ΕΛΛΑΔΟΣ ΚΑΙ ΑΦΡΙΚΗΣ ΓΥΡΩ ΑΠΟ ΤΟ ΜΕΓΙΣΤΟ ΤΟΥ 21ΟΥ ΗΛΙΑΚΟΥ ΚΥΚΛΟΥ (1978-1982)","EVENING-TYPE TRANSEQUATORIAL VHF PROPAGATION BETWEEN GREECE AND AFRICA DURING THE PEAK OF SOLAR CYCLE 21 (1978-1982)"],"dc:type":["PhD Thesis"]},"updated_at":"2026-07-24T02:25:27Z"}