# Applications of Computer Technology in the distance calculation train radio

D is now to calculate the distance of train radio meter wave band is used the method described in the book «Mobile Communications in rail transport» Vavanova Yu et al.

In order to facilitate and accelerate the process of calculations by this method and to relieve the designer from having to use multiple nomograms, we offer a program computing programmable calculator-type BZ34 and its analogues. The program is designed for the general conditions of the design. Here and below we use the notation adopted in the book: U2min- minimum allowable voltage at the input station locomotive; Gi — stationary antenna gain; hi. h2-installation height and stationary locomotive antennas; 1sch-length stationary antenna feeder; Ke — coefficient of field screening body of the locomotive; P — the probability of exceeding a predetermined signal level.

The result of the calculation is the value of g-range radio communication confident. Furthermore, in the register RG4 is recorded in dB relative to 1 mV / m intensity values ​​E2 (0 field at the point of reception.

Used as a test to check the functionality of the program after its introduction is possible to offer an example of the type of route calculation 0 electrified section at U2min — 6 dB; Gi = 2 dB; hi = 18 m; h2 = 6,3 m; 1kh = 30 m; Ke = 2 dB; P = 95%, for which the result of calculations obtain E2 (0 5) -35.4 mV / m; z = 10.2 km.

It should be noted that the input program shown in the Table. 1 takes approximately 2.5 minutes, the initial input data for the calculation of one embodiment — not more than 1 m, calculating the variant produced within 32 seconds.

Note that the data entered in the registers RG8 and RG9, are the values ​​of the coefficients a and w = Ke1pR approximation Ki; data input registers RGA and RGB values ​​are coefficients of approximation a and b = Km (Ki Km — coefficients which particular values ​​for P = 90% are shown in Table. 7.4). Data entered into the registers RGC and RGD, are end values ​​of the coefficients of approximation.

By changes in the way data input can be lifted restrictions set forth in the beginning of this article. For example, in contrast to the transmitter power of 8 watts quantity correction coefficient in elevation from Fig. 7.12 can be accounted for by the entry in the register RG0 irrelevant U2min, and the values ​​U2min1BM. Similarly to proceed in the case of dB (RG0 is stored in the register without Uzmin, a Usmin-1 +

The procedure for calculation of the following. Press the button «F», introduced the program, press the «P» and «AUTO», introduced the initial data for the calculation of the first embodiment according to the table. 2 (a record number in the registers RG0 … RG9, RGA, RGB, RGC and RGD by dialing the number on the keyboard of the calculator and then pressing the «P» and one of the keys «0» … «9», «A» , «B», «C» and «D»), press the button / v and / n. After reading the calculation results (values ​​in g km), if appropriate reading values ​​E2 (0 5) in dB press «SP» and «4». In the transition to the calculations of the next version of the program is not administered and recorded in the memory registers only the raw data, the values ​​of which differ from the corresponding initial data for calculating the previous version.

In conclusion, we present a program to compute the values ​​of E2 5) and Mr. algorithmic language FORTRAN, which can be used without any noted earlier in this article limits for a large number of calculation options. The program includes the following notation T — type of tracks; Y-factor, the values ​​of which determine the nature of the site (Y == 1 — non-electrified section, Y ^ l-electrified section); U2 = iU2min; HI = hi, H2 = h2; Gl = Gi, G2 = g2; P — probability signal exceeding a predetermined level; LKl = lt; i, LK2-ak2; KE — coefficient taking into account the impact of the body of the locomotive; Ll = li; L2 = 12.