.net barcode reader library Ionospheric variation and disturbances in Software

Maker Data Matrix in Software Ionospheric variation and disturbances

Ionospheric variation and disturbances
Data Matrix 2d Barcode Scanner In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Make Data Matrix In None
Using Barcode creation for Software Control to generate, create Data Matrix 2d barcode image in Software applications.
The ionosphere is an extremely dynamic region of the atmosphere, especially from a radio operator s point of view, because it significantly alters radio propagation The
Scanning ECC200 In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
Data Matrix ECC200 Printer In C#
Using Barcode printer for Visual Studio .NET Control to generate, create Data Matrix image in Visual Studio .NET applications.
46 Radio-wave propagation dynamics of the ionosphere are conveniently divided into two general classes: regular variation and disturbances This section covers both types of ionospheric change Ionospheric variation There are several different forms of variation seen on a regular basis in the ionosphere: diurnal, 27-day (monthly), seasonal, and 11-year cycles Diurnal (daily) variation The sun rises and falls on a 24-hour cycle, and because it is the principal source of iononization of the upper atmosphere, you can expect diurnal variation During daylight hours the E and D levels exist, but these disappear at night The height of the F2 layer increases until midday, and then it decreases until evening, when it disappears or merges with other layers As a result of higher absorption in the E and D layers, lower frequencies are not useful during daylight hours On the other hand, the F layers reflect higher frequencies during the day In the 1- to 30-MHz region, the higher frequencies (>11 MHz) are used during daylight hours, and the lower frequencies (<11 MHz) at night 27-day cycle Approximately monthly, this variation is caused by the rotational period of the sun Sunspots are localized on the surface of the sun, so they will face the earth only during a portion of the month As new sunspots are formed, they do not show up on the earthside face until their region of the sun rotates earthside Seasonal cycle The earth s tilt varies the exposure of the planet to the sun on a seasonal basis In addition, the earth s yearly orbit is not circular; it is elliptical As a result, the intensity of the sun s energy that ionizes the upper atmosphere varies with the seasons of the year In general, the E, D, and F layers are affected although the F2 layer is only minimally affected Ion density in the F2 layer tends to be highest in winter, and less in summer During the summer, the distinction between F1 and F2 layers is less obvious 11-year cycle The number of sunspots, statistically averaged, varies on an approximately 11-year cycle As a result, the ionospheric effects that affect radio propagation also vary on an 11-year cycle Radio propagation, in the shortwave bands, is best when the average number of sunspots is at its highest Disturbances Disturbances in the ionosphere can have a profound effect on radio communications and most of them (but not all) are bad This section will briefly examine some of the more common forms Sporadic E layer A reflective cloud of ionization sometimes appears in the E layer of the ionosphere; this layer is sometimes called the Es layer It is believed that the Es layer forms from the effects of wind shear between masses of air moving in opposite directions This action appears to redistribute ions into a thin layer that is radio-reflective Sporadic E propagation is normally thought of as a VHF phenomenon, with most activity between 30 and 100 MHz, and decreasing activity up to about 200 MHz However, about 25 to 50 percent of the time, sporadic E propagation is possible on frequencies down to 10 or 15 MHz Reception over paths of 1400 to 2600 mi are possible in the 50-MHz region when sporadic E is present In the northern hemisphere, the months of June and July are the most prevalent sporadic E months On most days when sporadic E is present, it lasts only a few hours Sudden ionospheric disturbances (SIDs) The SID, or Dellinger fade, mechanism occurs suddenly, and rarely gives any warning The SID can last from a few minutes to many hours It is known that SIDs often occur in correlation with solar
Printing Data Matrix ECC200 In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create Data Matrix image in ASP.NET applications.
Print Data Matrix In VS .NET
Using Barcode generator for Visual Studio .NET Control to generate, create ECC200 image in Visual Studio .NET applications.
EM wave propagation phenomena 47 flares, or bright solar eruptions, that produce an immense amount of ultraviolet radiation that impinges the upper atmosphere The SID causes a tremendous increase in D layer ionization, which accounts for the radio propagation effects The ionization is so intense that all receiver operators on the sunny side of the earth experience profound loss of signal strength above about 3 MHz It is not uncommon for receiver owners to think their receivers are malfunctioning when this occurs The sudden loss of signals on sunny side receivers is called Dellinger fade The SID is often accompanied by variations in terrestrial electrical currents and magnetism levels Ionospheric storms The ionospheric storm appears to be produced by an abnormally large rain of atomic particles in the upper atmosphere, and is often preceded by SIDs 18 to 24 hours earlier These storms tend to last from several hours, to a week or more, and are often preceded by two days or so by an abnormally large collection of sunspots crossing the solar disk They occur, most frequently, and with greatest severity, in the higher latitudes, decreasing toward the equator When the ionospheric storm commences, shortwave radio signals may begin to flutter rapidly and then drop out altogether The upper ionosphere becomes chaotic; turbulence increases and the normal stratification into layers, or zones, diminishes Radio propagation may come and go over the course of the storm, but it is mostly dead The ionospheric storm, unlike the SID, which affects the sunny side of the earth, is worldwide It is noted that the MUF and critical frequency tend to reduce rapidly as the storm commences An ionospheric disturbance observed in November 1960 was preceded by about 30 minutes of extremely good, but abnormal, propagation At 1500 hours EST, European stations were noted with S9+ signal strengths in the 7000- to 7300-kHz region of the spectrum, which is an extremely rare occurrence After about 30 minutes, the bottom dropped out and even AM broadcast band skip (later that evening) was nonexistent At the time, the National Bureau of Standards* radio station, WWV, was broadcasting a W2 propagation prediction at 19 and 49 minutes after each hour (which is terrible!) It was difficult to hear even the 5-MHz WWV frequency in the early hours of the disturbance, and it disappeared altogether for the next 48 hours This signal s fade-out occurred during the weekend of the annual ARRL Sweepstakes contest
ECC200 Drawer In VB.NET
Using Barcode printer for Visual Studio .NET Control to generate, create Data Matrix ECC200 image in .NET framework applications.
Drawing GS1 128 In None
Using Barcode drawer for Software Control to generate, create GS1-128 image in Software applications.
Printing Bar Code In None
Using Barcode generation for Software Control to generate, create bar code image in Software applications.
Creating USS Code 128 In None
Using Barcode creation for Software Control to generate, create Code 128 Code Set A image in Software applications.
GTIN - 12 Maker In None
Using Barcode creator for Software Control to generate, create UPC A image in Software applications.
Drawing Code 39 Extended In None
Using Barcode maker for Software Control to generate, create Code 39 Full ASCII image in Software applications.
British Royal Mail 4-State Customer Barcode Generator In None
Using Barcode maker for Software Control to generate, create British Royal Mail 4-State Customer Barcode image in Software applications.
Bar Code Decoder In C#
Using Barcode Control SDK for Visual Studio .NET Control to generate, create, read, scan barcode image in VS .NET applications.
Scanning Code 39 Full ASCII In Visual Basic .NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
Bar Code Recognizer In Java
Using Barcode Control SDK for Eclipse BIRT Control to generate, create, read, scan barcode image in Eclipse BIRT applications.
Making Barcode In Objective-C
Using Barcode drawer for iPhone Control to generate, create barcode image in iPhone applications.
Paint UPC-A In None
Using Barcode encoder for Online Control to generate, create UPCA image in Online applications.
ANSI/AIM Code 128 Generation In None
Using Barcode drawer for Microsoft Word Control to generate, create Code 128 Code Set A image in Word applications.
EAN / UCC - 13 Creation In VB.NET
Using Barcode generation for .NET Control to generate, create UCC-128 image in Visual Studio .NET applications.
Copyright © OnBarcode.com . All rights reserved.