The k index is measured on a scale of 0 to 9, where 0 is the quietest and 9 is the most disturbed. Any white bubble indicates no suitable frequency or high absorption. Schwarz has prepared a handy pdf guide to interpreting the. The basic concepts behind hf propagation using the ionosphere are easy to understand, and a study of it is not only fascinating, but also very useful for anyone involved in hf radio communications in any way. Ionospheric propagation is the main mode of radio propagation used in the mf and hf portions of the radio spectrum. Transmitting power antennas transmission mode noise. Hf propagation prediction programs and how to use them. This presentation examines hf propagation hf region spans 3 to 30 mhz. Introduction to hf radio propagation pdf big guns guide to low.
Radiowave propagation in the earths crust nvlpubsnistgov. The k index is computed once every three hours eight times a day and the values can range from 0 to 9, with 0 being. We all know the sun goes through a solar cycle about every 11 years. Review of propagation prediction programs voacapbased. The main category is propagation tools that is about propagation prediction software for ham radio. And theyre using the propagation of radio waves from both space and the ground to. Radio and tv signals arent always limited to traveling line of sight distances. Aann iinnttrroodduuccttiioonn ttoo hhff pprrooppaaggaattiioonn by sean d. Instead of speaking of propagation in terms of ionospheric layers, that nobody can really materialize, amateurs and listeners are used to speak in terms of frequencies or bands. This concept occurred to tbe writer recently during discllssions with. Usable hf frequencies page refreshed every 20 minutes use the indicated color red, yellow, green, blue, white, etc. Generally, the greater the number of electrons, the higher the frequencies that can be used. Irregular terrain model itm longleyrice 20 mhz 20 ghz if77. Time of day time of year band in use solar flux em radiation geomagnetic conditions solar particulate output the path itself over land.
Overview of hf propagation characteristics of hf radio propagation propagation is possible over thousands of miles. It has daily and seasonal variation, as well as a much longer 11 year cycle. The dlayer absorbs hf radio waves, especially up to 10 mhz. The surface wave propagation depends on currents which flow in the ground. K index is a measure of the state of the geomagnetic field. Aspects of hf radio propagation article pdf available in annals of geophysics annali di geofisica 5234. While listening or planning to work a dx station, the radio amateur would like to know what are the current propagation conditions, know if the propagation is open toward a specific location at a specific time, or at what time the band will be open for a specific.
After answering questions at the 2009 and 2010 newark hamfests it dawned on me that these features could be bundled together into a single pdf, so giving the reader a good grounding in lf and hf propagation. Regardless of what type of antenna you are using, the radio waves emanating. However, a virtual height of a region may be obtained by. Propfire is a web browser extension that allows users to view hf propagation conditions on their web browser status bar. Acehf system simulation and visualization software, v2. Oneway propagation revisited carl luetzelschwab k9la. The main category is the beginners guides to radio wave propagation that is about guide to radio wave propagation, studies, guides and documentation. Ntia does not make any warranty of any kind, express, implied or statutory, including, without limitation, the. Issn 02841703 we discuss various topics concerning the propagation, generation, and detection of highfrequency hf radio waves in the earths ionosphere. Groundwave propagation occurs, for example, when you contact another station across town on an hf band. During solar maxima, the whole hf range up to 30 mhz can be used and f2 propagation up to 50 mhz are observed frequently depending upon daily solar flux values.
A comprehensive propagation resource compiled by tomas hood, editor of the propagation columns of cq, cq vhf, popular communications, and monitoring times magazines. Cd now available 792009 signaltonoise predictions using voacap written by george lane under contract from rockwell collins george lane was instrumental in the development of ioncap while working 17 years for the us army, and steered the development of voacap while working years for the voice of america. On frequencies higher than this, while solar activity plays a role, earth based weather. Unless otherwise stated, all originally authored software on this site is licensed under the terms of gnu gpl version 3. An introduction to hf propagation steve foy n4foy paul white n4wgl upper pinellas amateur radio club tech program series. Interfacing with a notebook computer is performed by a parallel printer. High frequency radio propagation latest smoothed sunspot.
Propfire ham radio propagation in firefox hf propagation info on your web browser status bar for ham radioshortwave. The sun, being the largest engine in our solar system, has a great effect on propagation as its exhaust interacts with our earths magnetic field. It is the ions that give their name to the ionosphere, but it is the much lighter and more freely moving electrons which are important in terms of high frequency hf. Institute for telecommunication sciences resources radio propagation software high frequency windows 32bit hf propagation models. Pdf a wide variety of unique systems and components inhabits the hf, vhf, and uhf bands. Each of the satellites continuously broadcasts a reference signal. This site is dedicated to voacap voice of america coverage analysis program for hf propagation prediction and ionospheric communications analysis, an improved and corrected version of ioncap, retaining all of the theory as put forth by john lloyd, george haydon, donald lucas and larry teters in the 19751985 timeframe with modifications which were suggestedapproved by george.
X and o mode propagationfrom eric nichols, kl7aj the fact of the matter is that a good deal of the weirdness of h. From the point of view working group 2 of the cost 296 action, interest lies with effects associated with propagation via the ionosphere of signals within the hf band. Australian government introduction to hf radio propagation. Thus, an hf system might seem to have been the best solution in this case.
The global positioning system gps consists of a network of satellite transmitters in orbit around the earth. Richard and sue buckner teamed with joe ahlgren author of geoclock and steve biro to create a dynamic system simulation and visualization software package which uses the voacap propagation prediction engine to create animated maps and charts to help all users of hf radio choose the best times and frequencies for communications. Hf propagation has bandspecific features frequency hf propagation has a geographical direction. All predictions are performed using the itus iturhfprop application. First, we depend on ionization of the upper atmosphere. Gilbert mipre, g4ucj this article is designed to be an introduction to the terms and basic mechanics of propagation methods that are to be found on the hf and vhf bands. The descriptions of the terms quite basic in order to keep them understandable, so. Hf propagation prediction programs and how to use them steve nichols g0kya. Institute for telecommunication sciences resources radio propagation software radio propagation software. High frequency hf is the itu designation for the range of radio frequency electromagnetic. But, true to form, most hams generally just ignore the whole topic and chalk up weird propagation to black magic. Solar weather, sunspot activity, geomagnetic, aurora, ionospheric reports via.
The only mf amateur band, 160m, will not be discussed, nor will bands above 10 meters. Using custom sdr software and a special downconverter tapped into the. An introduction to hf propagation resource detail the. Using custom sdr software and a special downconverter tapped into the ifstage of a shortwave receiver or ham transceiver, the rfseismograph monitors changes in. The downloads made available through links on this page contain software developed by ntia. The drivermust supply a significant negative voltage to produce. On hf this is commonly caused by refraction bending of the signal at the upper layers of the atmosphere known as the ionosphere. At that time worldradio was a printed magazine, which then turned into an online magazine and then was absorbed into cq plus. Band propagation robert brown, nm7m sk selected propagation topics by carl luetzelschwab, k9la. Let me put out a few remarks that might help your understanding of propagation.
The home of the online hf propagation prediction tool, proppy, providing ondemand pointtopoint and area predictions using the itus iturhfprop application in accordance with itur p. Solar weather, geomagnetic, aurora, ionospheric reports via ealerts and webpage. Hf propagation prediction the tools provided by this web application enable users to predict available frequencies, signal levels and corresponding reliabilities for high frequency hf circuits. The only mf amateur band, 160m, will not be discussed, nor. Berkeley introduction i i have to agree there is a lot of information out there on the internet. Lf propagation a topic he is very well placed to explain. Higher sunspot numbers indicate increased ionizing radiation from the sun which enhances the ionospheres ability to refract hf signals, the sunspot number can vary from zero to over 200 during the peak of the 11year solar cycle. High frequency and vhf radio propagation data, solar and geomagnetic realtime and historic data, sunspot activity reports, as well as forecasts.
However hf bands seem to open miraculously during contests, only to appear to close again afterwards, as everyone who would normally be on hf tries their hand at gardening or similar. Hf shortwave radio propagation information a index and k. Amateur com munications of up to 50 miles are typically possible via ground wave. Advanced users of high frequency hf radio communications have long used systems known as chirpsounders1 to obtain realtime information about the ionospheric propagation conditions of different communication channels between a transmitter and a receiver. About an introduction to hf propagation the resource is currently listed in in a single category.
Hf radio waves may travel by any of the following modes. Space weather impacts radio communication in a number of ways. A rudimentary knowledge of sunspots, solar flares and mass ejections will help the amateur take advantage of these effects to enhance his pleasure, or understand his plight. Ham radio operators and other shortwave radio enthusiasts will be able to monitor propagation conditions using this firefox extension. Pdf hf, vhf, and uhf systems and technology researchgate. G0kyas hf shortwave propagation predictions from the uk for all bandsall hours. Hf propagation app for windows resource detail the. Pdf advanced users of high frequency hf radio communications have. Linux and printed on an hp laserjet 5000gn printer.
Hf shortwave radio propagation information a index and k index a index and k index the earths magnetic field is continuously monitored by a network of magnetometers. It harbours the so called elayer, f1layer and f2layer. The first hf propagation models were manual methods developetd in the mid. Hf band 330 mhz, it is possible to transmit signals for very great distances with very modest equipment and antennasa fact well known to radio amateurs. The ionosphere is very important when it comes to propagation of hf radio waves. Understanding radio wave propagation can mean the difference between making and missing a contact to a particular part of the world. These readings are converted into the a and k index values. February 2015 one of my early columns was titled oneway propagation, and it was in the august 1998 issue of worldradio. About hf propagation app for windows the resource is currently listed in in a single category. Paper presented at conference on tbe propagation of elf radio waves. This includes the 80, 40, 30, 20, 17, 15, 12, and 10 meter bands. High frequecy and vhf radio propagation data, solar and geomagnetic realtime and historic data, as well as forecasts.
During solar minima, propagation of higher frequencies is generally worse. This link is listed in our web site directory since monday apr 8 20, and till today hf propagation app for windows has been followed for a total of 1550 times. This free software is a product of institute for telecommunication sciences. The software lies within system utilities, more precisely general.
Current sunspot cycle activity, space weather, solar storm. Interactions among ionosphere propagation, hf modems, and data protocols. At frequencies in the 1 to 30 mega hertz range known as high frequency or hf radio, the changes in ionospheric density and structure modify the transmission path and even block transmission of hf radio signals completely. Applications of radiowave propagation university of illinois at. This link is listed in our web site directory since thursday sep 23 2010, and till today an introduction to hf propagation has been.
There are, however, several drawbacks to this solution. Gang, for those of you who seem hopelessly lost with all this solar and propagation stuff, i will attempt a quick primer that will hopefully help. Vhf and uhf propagation is an entirely different subject. Pv hamiltonian formulation of radio wave propagation in a cold, stratified magnetoplasma.
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