Comparison of M(3000)F2 Variation between Measured Data by Ionosonde and IRI-2016 Model Data over Chiang Mai, Thailand

Comparison of Prediction Programs for Short Wave Circuit Link from Iraq to Test points on Both Earth Hemispheres during Solar Minimum

“…To make a radio contact successfully on HF between two points, if a frequency is greater than the Maximum Usable Frequency ( MUF), the signal will penetrate the ionosphere and escape to space and never come back to earth again ,so the working frequency must be less than the MUF and is called the Frequency of Transmission (FOT) [4]. The job of the prediction programs is to predict the FOT and MUF for any circuit link between two points at any time [5]. Most of the prediction program results are approximately convergent with points of one hop distance while they diverge (with acceptable error) in points with multiple hop distances, especially in points located near the geomagnetic equator line [5][6][7].…”

“…The job of the prediction programs is to predict the FOT and MUF for any circuit link between two points at any time [5]. Most of the prediction program results are approximately convergent with points of one hop distance while they diverge (with acceptable error) in points with multiple hop distances, especially in points located near the geomagnetic equator line [5][6][7]. Most of these programs use input variables such as the Sun Spot Number (SSN) , date, geographical location, and the antenna type for prediction [6], and do not use important variables like K and A [8] even though the K parameter represents the status of solar winds.…”

“…The A parameter is a linear variable that represents the magnetic field of the earth. The previous papers [1][2][3][4][5][6][7][8][9][10] focused on the comparison of prediction programs at different geomagnetic circuits and different solar activity without mention to the Iraqi HF circuit link, while [11,12] studied the ionospheric parameters for Iraq's zone only when solar winds were at their maximum. The novelty of this work is studying and comparing the propagation prediction for the HF circuit link from Iraq to the world at the solar wind's minimum using the Voice of America Coverage Analysis Program (VOACAP), ITU Recommendation RS 533 (REC533), and real radio contact during August 2018; and also to find which modulation is preferred digital mode like FT8 [13] or analogue.…”