EA4FSI
Antenna Modelling and Simulation
Notes on Antenna Simulation using NEC-2
Notes and recommendations about antenna simulations using software based on the NEC-2 algorithm, developed by the Lawrence Livermore National Laboratory. The recommendations and rules of design have been compiled both from the manuals of some programs and from technical articles about antenna simulation. Article published in the Spanish Amateur Radio Union Magazine (URE). December 2012.
HF Propagation
Geometry and Operative Aspects of the Simple Modes of Ionospheric Propagation
Geometry of ionospheric propagation through successive hops, including radio-path length, hop distance, coverage areas, power budgets and maximum usable frequency.
NVIS Communications in the HF Band
Article about the Near Vertical Incident Skywave (NVIS) HF propagation mode, used at great length in emergency and tactical communications. The article was published in the Spanish Amateur Radio Union (URE) magazine, in november 2008.
NVIS Propagation: Study and Experiences
Transcription of the original article by the then Captain Julián Iranzo Collado of the 21st Tactical Signals Regiment of the Spanish Army, published in the "Memorial del Arma de Ingenieros" (Spanish Army Corps of Engineers Magazine), nº37, year 1989. Reproduced with permission. Available in Spanish only.
NVIS Propagation Model: A Practical Case Study
Transcription of the original article by the then Captain Julián Iranzo Collado of the 21st Tactical Signals Regiment of the Spanish Army, published in the "Memorial del Arma de Ingenieros" (Spanish Army Corps of Engineers Magazine), nº39, year 1990. Reproduced with permission. Available in Spanish only.
Daily Evolution of the Ionosphere
Illustrative video showing the evolution of the different layers of the ionosphere over a full day, at 15-minute intervals, using data recorded by the El Arenosillo ionospheric sounding station in Huelva (Spain), operated by the Spanish National Institute of Aerospace Technology (INTA). The data collected by the ionosonde are stored in SAO-format files and can be viewed with SAO Explorer, developed by the Center for Atmospheric Research at the University of Massachusetts Lowell.
HF Network Planning
HF Radio Link Planning
This article presents a methodology for frequency planning in the HF band, taking into account network topology, technical parameters, ionospheric propagation conditions and the operating bands in which frequency allocations are available. Published in issue 92 of the Spanish Army Corps of Engineers magazine Memorial de Ingenieros (July 2014). Available in Spanish only.
HF Link Calculations and Predictions
HF Propagation Forecasts by EA3EPH
HF propagation calculations and forecasts prepared by Alonso Mostazo Plano (EA3EPH) using his "Sondeo" software. The bulletins are commonly issued during disaster-mitigation operations in which amateur radio operators may participate. EA3EPH has provided this bulletin service since 2010.
HF Link Calculation: W6ELProp Manual in Spanish
W6ELProp, developed by Sheldon C. Shallon (W6EL), calculates the maximum usable frequency (MUF) and optimum working frequencies for HF radio links between stations located anywhere in the world and for any time of day. A comprehensive Spanish-language manual with practical examples is provided.
HF Link Calculation: PropView Manual in Spanish
Spanish-language user manual for PropView, which provides simplified HF radio-link calculations based on the IONCAP model.
Space Weather
Risks derived from the Space Weather (ESP)
Report presented in November 2010 to the Spanish General Directorate of Civil Protection and Emergencies (DGPCE), on the occasion of the Technical Congress on Space Weather. The article provides a description of the Space Weather phenomena and an analysis of the risks for people and several technological systems, among them the HF radio communication systems. The article also provides a description of the observation and early warning systems currently available in several countries.
Impact of the severe Space Weather events on the terrestrial radio communication systems (ESP)
Lecture on the impact of the severe Space Weather events on the terrestrial radio communication systems, presented in the Spanish National Civil Protection School (General Directorate of Civil Protection and Emergencies, Ministry of Interior) during the "Conference on Space Weather", 23-24 March 2011. Available in Spanish only.
Direction Finding
Adcock/Watson-Watt Radio Direction Finding
Technical description of Adcock/Watson-Watt radio direction-finding systems, based on four monopoles with an additional sense antenna to resolve ambiguities. These systems are commonly used in military (SIGINT), radionavigation and emergency radiolocation applications in the MF, HF, VHF and UHF bands. The theoretical treatment is supported by radiation-pattern simulations made with 4Nec2 and by analysis of demodulated signals using function-plotting software.
Reference
HF Radio Communications Glossary
A collection of definitions of terms related to radio communications in the HF band. The glossary currently contains 207 terms.
Emergency Communications
Emergency Telecommunications Glossary
A collection of definitions of terms relating to emergency telecommunications, amateur radio, civil protection and communications systems.
Radiograms
A practical guide to using radiograms for reliable message handling through Amateur Radio and REMER emergency communications networks.