Maximum usable frequency map. MUF = critical frequency/cosθ.

Maximum usable frequency map com Jul 15, 2020 · Abstract Since 1988 the Upper Atmosphere Physics unit of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) has provided maps of Maximum Usable Frequency (MUF) and skip distance over a European area extending in latitude from 34°N to 60°N and in longitude from 5°W to 40°E. If the frequency of the radio signal becomes high enough, it will penetrate the ionosphere and be lost to outer space as illustrated by the black 15 meter (21 MHz) trace in Figure 1. the recent high resolution map of maximum usable frequencies mufs for 3 000 kilometer radio signal paths this map is useful to determine maximum usable frequencies for any world wide path at the indicated utc zulu time . net/ is, say, 22 MHz, then 10m won't be propagating because… Since 1988 the Upper Atmosphere Physics unit of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) has provided maps of Maximum Usable Frequency (MUF) and skip distance over a European area extending in latitude from 34 N to 60 N and in longitude from 5 W to 40 E. This should not be confused with "Critical Frequency". > Excellent map for this. 3 days ago · Current vertical maximum usable frequency (MUF or foF2) Plots, HF Communications Warning, daily ionospheric summary and forecast and real time MUF report The maximum usable frequency (MUF) is important ionospheric parameter for radio users because of its role in radio frequency management and for providing a good communication link between two locations (Athieno et al. Image courtesy of the KC2G propaation pages Current Sun Images The images below are current views of the sun shown at different wavelengths of light as taken by SOHO and the Yohkoh soft-Xray telescope. The highest frequency . e. Oct 18, 2025 · 18 Maximum Usable Frequency A radio signal travels progressively higher into the ionosphere as its frequency increases and its wavelength becomes shorter, as illustrated in Figure 1. https://vhf. com An interactive map that shows real time, worldwide HF activity and propagation specific to the user's location on all amateur radio HF bands. ionospheric propagation maps muf and critical frequency. Maximum Usable Frequency (MUF) On-screen topographical and color heat-map profile of Maximum Usable Frequencies around the world, showing the highest frequency available using ionospheric skip propagation using predictive models from NOAA and the Lowell Global Ionospheric Radio Observatory. For an easy explanation on both watch the Youtube video below the MUF map. 4 days ago · The foF2 frequency is the highest frequency which will be reflected back to the Earth with a vertical incidence (straight up and down). Aug 17, 2022 · This MUF map is a useful real-time indicator for HF propagation conditions. Nov 9, 2025 · Australian Region conditions at: 1000 UT 09/11/25 Station Vertical Maximum Usable Frequencies (MUFs) - average over last 2 hours ===================================================================================== Brisbane : near normal Canberra : near normal Cocos Is : near normal Darwin : enhanced by 64% Hobart : near normal Learmonth : near MAPS,PREDICTIONCHARTSANDAIDS Agooddealofthematerialinthissectionhasbeentaken iirectlyfromNationalBureauofStandardsCircular465. Each region’s MUF is represented by a numbered, colored disc, indicating the highest frequency suitable for long-distance (3,000 km prop. > For paths that are more typical of "DX" (3000 km paths), there is also > this map: > http://www. The grey line position is also provided. Be able to explain how various environmental and engineering factors control the values of the plasma frequency, the critical frequency (fo), the maximum usable frequency (MUF), the lowest usable frequency (LUF) and The map linked to the right represents current VHF (2m maybe 6m) tropo propagation. ) digital ionospheric sounding data and predicted (pre. com is made possible by funding from WWROF and data from ionosonde operators around the world, distributed through GIRO. " The International Telecommunications Union ITU-R (Recommendation P. The top two panels show the latest global Total Electron Content (TEC) and Maximum Usable Frequency (MUF) as forecasted by the WAM-IPE. Maximum Usable Frequency (MUF) Report? Other than the Ham Radio QSL website, does anyone know of a website that gives the current Maximum Usable Frequency? Archived post. See Acknowledgments. These values can be used with the Skip Zone calculator below. During a solar flare, the LUF may rise swiftly, narrowing the usable HF skywave window. MUF, LUF, and FOT - The Basics of the Maximum Usable Frequency There are two definitions for the abbreviation, "MUF. 2 days ago · The Maximum Usable Frequency (MUF) is the highest frequency radio waves can use to bounce off the ionosphere for long-distance communication. This index is especially useful for shortwave transmissions. MUF (Maximum Usable Frequency) Estimator (coming soon) LUF (Lowest Usable Frequency) Estimator (coming soon) Gray Line Propagation Map Generator (interactive) (coming soon) Sunrise/Sunset and Greyline Calculator by Location (coming soon) 🧰 Transmission Line & Impedance Calculators Coax Loss Calculator (based on type, length, and frequency) The MUF map shows the Maximum Usable Frequency using colors and contour lines. The bottom two panels show the anomaly in TEC and MUF taking the difference between the latest values and a 10-day running average at the same universal time. FMUF: F region maximum usable frequency OWF: The optimum working frequency is usually 85% of the MUF. In this highly informative and engaging presentation, we delve into the topic of Ham Radio Propagation and explore the relationship between MUF (Maximum Usable Frequency) and critical frequency Maximum usable frequency (MUF) is dependent on the angle of incidence θ. ) to determine the recommended HF frequencies for contacts from your nearest BASE (New York, Boston, Atlanta, Orlando, Kansas City, Phoenix, San Francisco, and Seattle) to a desired location (local region, country, or continent). 2 days ago · The map is useful in determining the maximum frequency that can be used for NVIS communications, however, the D-Layer absorption frequency, which is not depicted on the map, must be considered in order to determine the minimum frequency that is usable for NVIS or long-hop communications. In radio transmission, maximum usable frequency (MUF) is the highest radio frequency that can be used for transmission between two points on Earth by reflection from the ionosphere (skywave or skip) at a specified time, independent of transmitter power. It is the highest frequency you can use to send radio signals successfully. Amateur Radio: Usable HF Frequencies (page refreshes every 20 minutes) Use the indicated color (red, yellow, green, blue, white, etc. The project "Understanding HF Propagation" explores HF skywave propagation, including LUF and MUF concepts. ^This circularisprobablyfamiliartomanyusersofthisreportand itwasfeltthatasithasstoodthetestofmanyyearsofser T vicethat,whereapplicable,theuseofthesametextwouldaid indeterminingF2-layerMUFsfromthematerialincludedherein. , 2015; Suparta et al. Tell distances, directions of antennas. For example, if a given area on the map is greenish and lies between the contours labeled "15" and "17", then the MUF is around 16MHz in that location. May 28, 2010 · Just enter the coordinates of the transmitter and receiver sites and VOACAP Online uses the Voice of America Coverage Analysis Program (VOACAP) to calculate the maximum usable frequency (MUF) of the HF path between the sites. Critical frequency is the maximum frequency at which During a strong Sudden Ionospheric Disturbances (SID), the LUF will increase to a frequency higher than the MUF, thus closing the usable frequency window, an event called a fadeout or blackout. Multiplying the foF2 critical frequency by 3 approximates the MUF. Sep 11, 2023 · The Maximum Usable Frequency (MUF) is the highest frequency that supports ionospheric propagation between two points. Operational MUF (or just MUF) is the highest frequency that would permit acceptable operation of a radio service between given terminals at a given The maximum usable frequency (MUF) is the highest frequency that can be reliably used for long-distance communication at any given time. Using this Map This is a highly informative map that can be used by amateur and professional radio communicators to determine maximum usable frequencies for any world-wide path at the indicated UTC (Zulu) time. It is affected by various factors, including ionospheric conditions, time of day, and location. See full list on prop. Real-time MUF (Maximum Usable Frequency) map for may help you understand HF propagation conditions. w5mmw. It is not dependent on the path as it is a straight up and down value that quantifies the state of the ionization above that location. Dec 5, 2024 · Enter the critical frequency and incidence angle into the calculator to determine the maximum usable frequency (MUF). World maps of F2 critical frequencies and maximum usable frequency factors: Published January 1, 1959 The 'critical frequency' is the highest frequency that gets reflected when it is aimed straight up at the ionosphere. MUF = critical frequency/cosθ. Apr 15, 2022 · That is why the operational frequency can’t be selected arbitrarily for HF radio systems. Because of the variability of the ionosphere this type of prediction can only be made for the current hour. Near real time global vertical MUF (maximum usable frequency) map, which can be used for an indication of near vertical incidence ionospheric frequencies of support For amateur radio uses (HamRadio), World globe and maps, with live/realtime MUF maximum usable frequency, foF2 and Aurora Borealis layer. A real-time Maximum Usable Frequency (MUF) map reveals HF propagation conditions in the last 15 minutes. Operating HF radio systems are usually guided by the Maximum Usable Frequency (MUF), Optimum Working Frequency (OWF), Height Probable Frequency (HPF), and Lowest Usable Frequency (LUF) (ITU, 2007, ITU, 2019). Solar Weather Region 6 Army MARS would like to thank the scientists and research teams at The University of Massachusetts Lowell Center for Atmospheric Research for providing this valuable resource allowing us to determine the critical frequency (foF2) and maximum usable frequency (MUF). html That's the 'other' map on that site. Oct 1, 2025 · This paper presents a procedure to simulate climatological maps of the F2-layer basic Maximum Usable Frequency (MUF) and corresponding skip distance p… Using High Frequency Propagation to Calculate Basic Maximum Usable Frequency Israa Abdualqassim Mohammed Ali* * University of Baghdad, College of Science, Baghdad, Iraq Received: XX 20XX / Accepted: XX 20XX / Published online: ABSTRACT A comparison between observed (obs. For longer hops, break your path down into 3,000 km segments, and choose the lowest frequency of the midway points. fc = The ionosphere’s Critical Frequency. These tools consider various factors such as time of day, solar activity, and geographic location to provide accurate and up-to-date information. ) using International Reference Ionosphere (IRI) model for critical Critical frequency can be computed by: where MUF is maximum usable frequency and is the angle of incidence [2] These HAP maps are "Hourly Area Predictions" of communication frequencies based on current observed conditions in the North America ionosphere. dxview. 4. The frequency at which communication just starts to fail is known as the Maximum Usable Frequency (MUF). The following color chart is adjusted to indicate the MUF. The MUF and its counterpart LUF (Lowest Usable Frequency) vary throughout the day and year because the ability of the ionosphere to reflect radio waves at a certain frequency depends on its exposure to solar radiation. This is a Maximum Usable Frequency Map in MHz. Dec 25, 2024 · The maximum usable frequency (MUF) is the highest frequency that, with a probability of 50% of the time, can be used for radio communication between two points at a specified distance (but not necessary in all directions) via refraction by the ionosphere. So it is a measure of the electron density above a particular location. Anyhow, these maps suffer the following restrictions: (1) they are provided with two months in advance and so they are not • Working at the Maximum Usable Frequency is literally “living on the edge”. Other Solar Weather Links of Interest GAMBIT - Global Assimilative Model of Bottomside Ionosphere Timeline Mar 23, 2021 · courtesy of K1EHT MUF c = sin E MUF = Maximum Usable Frequency E = Elevation angle of the signal radiating from your antenna. com/www/realtime. EMUF: E region maximum usable frequency LUF: The lowest usable frequency due to D-region absorption. MUF is typically quoted as the maximum frequency supported Use a real-time online MUF km 3000 Map to find the optimal frequencies and communication routes. The map shows MUF (Maximum Usable Frequency) levels across different regions, based on data from ionosondes. 7. Listed under the Propagation/MUF Indicators category that is about MUF Indicators. This is a first step in predicting MUF or MOF(the Maximum-Observed MUF Maximum Usable Frequency Make More Miles reported value (used with permission). , 2018). A simplified explanation of Maximum Usable Frequency (MUF) for HF Ham Radio #hamradio #HFpropagation #amateurradioLink to KC2G MUF Map: https://prop. Gray indicates No Sporadic E (ES) activity , blue indicates ES reported @ 6M, green indicates ES reported @ 4M, yellow indicates conditions support 2M ES, and red indicates reported @ 2M. Total visits since 17 August 2022. Provides the Maximum Usable Frequency in a colored bar. optimal working frequencies mhz for high frequency hf shortwave radio by region updated monthy . spacew. It is generally three to five times the critical frequency, dependent upon the layer being used and the angle of incidence. 6 days ago · Current HF NVIS Propagation foF2 Critical Frequency Map Where the above map indicates the foF2 NVIS Critical Frequency, the relationship between the foF2 frequency and the Maximum Usable Frequency (MUF) is approximately 1:3. Jul 15, 2020 · Abstract Since 1988 the Upper Atmosphere Physics unit of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) has provided maps of Maximum Usable Frequency (MUF) and skip distance over a European area extending in latitude from 34°N to 60°N and in longitude from 5°W to 40°E. :-) The problem always seems to me to be that it is 'DX' that many people concentrate on, when a lot of the paths most people actually use are high angle. Real-Time Propagation Maps and Charts display "Maximum Usable Frequency" (MUF) and other propagation parameters help visualize current conditions. Mar 1, 2024 · As the frequency of a radio signal increases, i. • Small changes in critical frequency and other ionospheric parameters cause the MUF to be in a continuous state of change. Jan 12, 2004 · HF Radiation - Choosing the Right Frequency Learning Objectives Be able to explain to radio operators and other technicians what controls HF propagation under normal conditions. The forecast is updated with the latest real-time and forecast solar and geomagnetic drivers at 0, 6 This map offers a quick visual snapshot of current DX conditions on 8 ham bands (60, 40, 30, 20, 17, 15, 12, 10 m) marked by iso-frequency contours. Do I understand this right? If the Maximum Usable Frequency shown at https://solar. MUF is "Maximum Usable Frequency". Updated every ½ hour. its wavelength becomes shorter It travels progressively higher into to the ionosphere Until at some point the signal penetrates the ionosphere and is lost to outer space The highest frequency signal that can be transmitted and return to Earth is the Maximum Usable Frequency (MUF) 4 days ago · MUF Indicators MUF Indicators Site Listings Calculation of the Maximum Usable Frequency This paper presents the method of calculating the maximum usable frequency MUF and field strength Be able to explain how various environmental and engineering factors control the values of the plasma frequency, the critical frequency (fo), the maximum usable frequency (MUF), the lowest usable frequency (LUF) and the frequency of optimum transmission (FOT) and why these parameters are important to HF. MUF map The following map shows Maximum Usable Frequencies (MUFs) for 3000 kilometer radio signal paths. kc2g. Any white "bubble" indicates no Dec 25, 2024 · On the other hand, oblique DX signals from Russia on 80 m remain unaffected as MUF 3000 km, the maximum usable frequency for 3000 km ionospheric hops, may still be as high as 7 MHz. New comments cannot be posted and votes cannot be cast. Generally it tells you the highest frequency you can use for hops of 3,000 km by looking at the midway point between you and your target. 373-7 10/1995, in force) recommends two definitions for MUF: 1. 1 day ago · Display up to 7 days foF2 maps and foF2 anomalies. org Below is the current MUF map for HF. 2 The Maximum Usable Frequency (MUF) ↗ (synonym: Highest Possible Frequency—HPF) is an index for forecasting propagation conditions. gwnn bxcfn qnlns wqzybt muzyp mkf poxzs svtip mpiqttx fvzj vxbz hev annxx oczx pclsewav