rgread.me

雷达作用距离计算

	 

     Program RGCALC has been designed to provide a user-friendly 
data-entry interface similar to a spread sheet.  Multiple calculations 
can be made simply by changing only the desired parameters and 
executing the program by use of the <Esc> key.  At any data entry 
input, the program can be terminated by simultaneously pressing the 
<Ctrl> key and either the <Break> key or the <C> key.  Output can be 
directed to LPT1:, LPT2:, LPT3:, COM1:, COM2:, or to the display screen 
only.

     When the program is first executed, an RGCALC Logo is displayed on 
the screen and the line on the bottom indicates "Press any key to 
continue."  At this point ,if the <Ctrl-Break> or <Ctrl-C> keys are 
pressed, the program will be terminated, and pressing any other key 
will cause the program to continue.   

     Once a key is pressed, the screen is cleared and a hard copy 
set-up is displayed.  The set-up is simply selecting a number from one
to six which will direct the calculated results to a hard copy device 
connected to LPT1:, LPT2:, LPT3:, COM1:, COM2:, or to the display 
screen only.  Actually, abbreviated results are always displayed on the 
screen, so selecting the screen-only option merely suppresses any 
hard copy output.  If output to one of the two communication ports is 
selected, they must have been initialized by use of the DOS MODE 
command prior to running RGCALC.  If a nonexistant port is selected, 
the program will display an error when it attempts to write to the 
nonexistant device.  Also, if a valid port is selected but does not 
have a device connected, the program will time-out after some period of 
time.  This time is variable, and it can range from seconds to minutes. 
This set-up must be accomplished once each time the program is run, but 
multiple calculations can be made without repeating the set-up 
procedure.  Also, an option is present on the data entry screen to 
suppress hard copy output, even if there has been selection a hardcopy 
device. To change the set-up, the program must be terminated and 
executed again.

     Once the hard copy selection has been made, the screen is cleared 
and all input prompts as well as default values are written to the 
display screen.  Defaults are set to one of the examples contained in 
the associated documentation accompanying this program.  Without making 
any changes to the default values, the program can be executed and the 
results compared to those of this example.

     Initially, all the default values are displayed in a field of 
inverse video, which represents the width of the input data field.  The 
width of these fields is sufficient for any single precision data-entry 
value where applicable.  A line at the bottom of the display indicates 
that the keypad up and down arrows control the location of the cursor 
for changing data values, and, after all entries are made, pressing the 
"Esc" key will perform the calculations. Due to space limitations, only 
the arrow keys are indicated as having control over the cursor.  
Additionally, the "Home" and "Pg Up" keys will locate the cursor at the 
beginning of the Radar Name input field (top of screen).  The "End" and 
"Pg Dn" keys will locate the cursor at the beginning of the hard copy 
data field (bottom of screen).  The "UP" and "DN" arrows as well as the 
carriage return key will locate the cursor at the beginning of the next 
data input field. These keys will also wrap from the top to the bottom 
and vice versa. The backspace key will delete the character immediately 
to the left of the cursor. There is no insert or delete capability, 
except for the backspace key.

     The change of a value in a data field will cause the inverse video 
of the changed characters to be replaced by normal video, either at the 
time the key is struck, or when the cursor is moved to a different data 
field, depending on the particular computer used. Normal video makes it 
very easy to see exactly what has been changed, and all changed values 
are carried forward to be used as the default value for any subsequent 
runs if you do not exit the program.   When displayed on a subsequent 
screen, the values will initially appear again in inverse video.

Note: To ensure that all data entries are properly entered, the cursor 
must be moved from the changed data field. This can be view as pressing 
the <Enter> key before the entry takes effect.

     After all data entries have been made, pressing the "Esc" key will 
cause the program to continue to execute.  The results will be 
displayed on the screen as well as the specified printer.  At the 
bottom of the screen that is displaying the calculated results, a line 
indicates that pressing any key will allow additional calculations to 
be made, or pressing the "Esc" key will cause the program to terminate. 
Press any key except the "Esc" key to clear the screen and redisplay 
all the input prompts with the last entered data values, which are to 
be used as default values for the current run.

     In addition to the above, an option has been included to allow the 
calculation of detection range, based on up to two specified 
signal-to-noise ratios.  To use this option, select Swerling 
fluctuation case 6 or 7.  Selection of case 6 or 7 will cause the 
screen to change when the cursor is moved from the Swerling fluctuation 
case field.  The probability of detection and probability of false 
alarm exponent fields will be rewritten to reflect signal-to-noise 
ratio.  If case 6 were selected, then detection range will be 
calculated, based on the signal-to-noise ratio entered in the first of 
these two fields. If case 7 were selected, the detection range will be 
calculated, based on both data fields. On this screen, the field labled 
"Number of pulses integrated" is meaningless, so ignore it.  

     There is only minor error checking performed on the input data 
fields prior to calculating the results.  If an error is detected, the 
program will cause all of the data fields detected as being in error to 
be displayed in inverse blinking video.  The cursor will be located at 
the beginning of the first field in which there was detection of an 
error.

     Error checking is as follows:

     * transmitter power less than or equal to zero;
     * pulse duration less than or equal to zero;
     * transmitted RF less than 30 MHz or greater than 150 GHz;
     * number of pulses integrated less than one;
     * probability of detection less or equal to zero or greater than .99;
     * false alarm exponent less than or equal to zero; 
     * Swerling fluctuation case less than zero or greater than seven; 
     * galactic noise with absolute value greater than one.