predict.c

一个预测卫星方位俯仰的软件

	}
}

/* PREDICT functions follow... */

void Banner()
{
	curs_set(0);
	bkgdset(COLOR_PAIR(3));
	clear();
	refresh();

	attrset(COLOR_PAIR(6)|A_BOLD);
	mvprintw(3,18,"                                           ");
	mvprintw(4,18,"         --== PREDICT v%sd ==--         ",version);
	mvprintw(5,18,"           By John A. Magliacane           ");
	mvprintw(6,18,"   KD2BD Software -- Copyright 1991-2002   ");
	mvprintw(7,18,"                                           ");
}

void AnyKey()
{
	mvprintw(23,24,"<< Press Any Key To Continue >>");
	refresh();
	getch();
}

void bailout(string)
char *string;
{
	/* This function quits ncurses, resets and "beeps"
	   the terminal, and displays an error message (string)
	   when we need to bail out of the program in a hurry. */

	beep();	
	curs_set(1);
	bkgdset(COLOR_PAIR(1));
	clear();
	refresh();
	endwin();
	fprintf(stderr,"*** predict: %s!\n",string);
}

void TrackDataOut(antfd, elevation, azimuth)
int antfd;
double elevation, azimuth;
{
	/* This function sends Azimuth and Elevation data
	   to an antenna tracker connected to the serial port */

	int n, port;
	char message[30]="\n";

	port=antfd;

	sprintf(message, "AZ%3.1f EL%3.1f \x0D\x0A", azimuth,elevation);
	n=write(port,message,30);

	if (n<0)
	{
		bailout("Error Writing To Antenna Port");
		exit(-1);
	}
}

double FixAngle(x)
double x;
{
	/* This function reduces angles greater than
	   two pi by subtracting two pi from the angle */

	while (x>twopi)
		x-=twopi;

	return x;
}

char *SubString(string,start,end)
unsigned char *string, start, end;
{
	/* This function returns a substring based on the starting
	   and ending positions provided.  It is used heavily in the
	   AutoUpdate function when parsing 2-line element data. */

	unsigned x, y;

	if (end>=start)
	{
		for (x=start, y=0; x<=end && string[x]!=0; x++)
			if (string[x]!=' ')
			{
				temp[y]=string[x];
				y++;
			}

		temp[y]=0;
		return temp;
	}
	else
		return NULL;
}

void CopyString(source, destination, start, end)
unsigned char *source, *destination, start, end;
{
	/* This function copies elements of the string "source"
	   bounded by "start" and "end" into the string "destination". */

	unsigned j, k=0;

	for (j=start; j<=end; j++)
		if (source[k]!=0)
		{
			destination[j]=source[k];
			k++;
		}
}

char *Abbreviate(string,n)
unsigned char *string, n;
{
	/* This function returns an abbreviated substring of the original,
	   including a '~' character if a non-blank character is chopped
	   out of the generated substring.  n is the length of the desired
	   substring.  It is used for abbreviating satellite names. */

	strncpy(temp,string,79);

	if (temp[n]!=0 && temp[n]!=32)
	{
		temp[n-2]='~';
		temp[n-1]=temp[strlen(temp)-1];
	}

	temp[n]=0;

	return temp;
}

char KepCheck(line1,line2)
char *line1, *line2;
{
	/* This function scans line 1 and line 2 of a NASA 2-Line element
	   set and returns a 1 if the element set appears to be valid or
	   a 0 if it does not.  If the data survives this torture test,
	   it's a pretty safe bet we're looking at a valid 2-line
	   element set and not just some random text that might pass
	   as orbital data based on a simple checksum calculation alone. */

	int x;
	unsigned sum1, sum2;

	/* Compute checksum for each line */

	for (x=0, sum1=0, sum2=0; x<=67; sum1+=val[(int)line1[x]], sum2+=val[(int)line2[x]], x++);

	/* Perform a "torture test" on the data */

	x=(val[(int)line1[68]]^(sum1%10)) | (val[(int)line2[68]]^(sum2%10)) |
	  (line1[0]^'1')  | (line1[1]^' ')  | (line1[7]^'U')  |
	  (line1[8]^' ')  | (line1[17]^' ') | (line1[23]^'.') |
	  (line1[32]^' ') | (line1[34]^'.') | (line1[43]^' ') |
	  (line1[52]^' ') | (line1[61]^' ') | (line1[62]^'0') |
	  (line1[63]^' ') | (line2[0]^'2')  | (line2[1]^' ')  |
	  (line2[7]^' ')  | (line2[11]^'.') | (line2[16]^' ') |
	  (line2[20]^'.') | (line2[25]^' ') | (line2[33]^' ') |
	  (line2[37]^'.') | (line2[42]^' ') | (line2[46]^'.') |
	  (line2[51]^' ') | (line2[54]^'.') | (line1[2]^line2[2]) |
	  (line1[3]^line2[3]) | (line1[4]^line2[4]) |
	  (line1[5]^line2[5]) | (line1[6]^line2[6]) |
	  (isdigit(line1[68]) ? 0 : 1) | (isdigit(line2[68]) ? 0 : 1) |
	  (isdigit(line1[18]) ? 0 : 1) | (isdigit(line1[19]) ? 0 : 1) |
	  (isdigit(line2[31]) ? 0 : 1) | (isdigit(line2[32]) ? 0 : 1);

	return (x ? 0 : 1);
}

void InternalUpdate(x)
int x;
{
	/* Updates data in TLE structure based on
	   line1 and line2 stored in structure. */

	double tempnum;

	strncpy(sat[x].designator,SubString(sat[x].line1,9,16),8);
	sat[x].designator[9]=0;
	sat[x].catnum=atol(SubString(sat[x].line1,2,6));
	sat[x].year=atoi(SubString(sat[x].line1,18,19));
	sat[x].refepoch=atof(SubString(sat[x].line1,20,31));
	tempnum=1.0e-5*atof(SubString(sat[x].line1,44,49));
	sat[x].nddot6=tempnum/pow(10.0,(sat[x].line1[51]-'0'));
	tempnum=1.0e-5*atof(SubString(sat[x].line1,53,58));
	sat[x].bstar=tempnum/pow(10.0,(sat[x].line1[60]-'0'));
	sat[x].setnum=atol(SubString(sat[x].line1,64,67));
	sat[x].incl=atof(SubString(sat[x].line2,8,15));
	sat[x].raan=atof(SubString(sat[x].line2,17,24));
	sat[x].eccn=1.0e-07*atof(SubString(sat[x].line2,26,32));
	sat[x].argper=atof(SubString(sat[x].line2,34,41));
	sat[x].meanan=atof(SubString(sat[x].line2,43,50));
	sat[x].meanmo=atof(SubString(sat[x].line2,52,62));
	sat[x].drag=atof(SubString(sat[x].line1,33,42));
	sat[x].orbitnum=atof(SubString(sat[x].line2,63,67));
}

char *noradEvalue(value)
double value;
{
	/* Converts numeric values to E notation used in NORAD TLEs */

	char string[15];

	sprintf(string,"%11.4e",value*10.0);

	output[0]=string[0];
	output[1]=string[1];
	output[2]=string[3];
	output[3]=string[4];
	output[4]=string[5];
	output[5]=string[6];
	output[6]='-';
	output[7]=string[10];
	output[8]=0;

	return output;
}

void Data2TLE(x)
int x;
{
	/* This function converts orbital data held in the numeric
	   portion of the sat tle structure to ASCII TLE format,
	   and places the result in ASCII portion of the structure. */
 
	int i;
	char string[15], line1[70], line2[70];
	unsigned sum;

	/* Fill lines with blanks */

	for (i=0; i<70; line1[i]=32, line2[i]=32, i++);

	line1[69]=0;
	line2[69]=0;

	/* Insert static characters */

	line1[0]='1';
	line1[7]='U'; /* Unclassified */
	line2[0]='2';

	line1[62]='0'; /* For publically released TLEs */

	/* Insert orbital data */

	sprintf(string,"%05ld",sat[x].catnum);
	CopyString(string,line1,2,6);
	CopyString(string,line2,2,6);

	CopyString(sat[x].designator,line1,9,16);

	sprintf(string,"%02d",sat[x].year);
	CopyString(string,line1,18,19);

	sprintf(string,"%12.8f",sat[x].refepoch);
	CopyString(string,line1,20,32);

	sprintf(string,"%.9f",fabs(sat[x].drag));

	CopyString(string,line1,33,42);

	if (sat[x].drag<0.0)
		line1[33]='-';
	else
		line1[33]=32;

	CopyString(noradEvalue(sat[x].nddot6),line1,44,51);
	CopyString(noradEvalue(sat[x].bstar),line1,53,60);

	sprintf(string,"%4lu",sat[x].setnum);
	CopyString(string,line1,64,67);

	sprintf(string,"%9.4f",sat[x].incl);
	CopyString(string,line2,7,15);
				
	sprintf(string,"%9.4f",sat[x].raan);
	CopyString(string,line2,16,24);

	sprintf(string,"%13.12f",sat[x].eccn);
	
	/* Erase eccentricity's decimal point */

	for (i=2; i<=9; string[i-2]=string[i], i++);

	CopyString(string,line2,26,32);

	sprintf(string,"%9.4f",sat[x].argper);
	CopyString(string,line2,33,41);

	sprintf(string,"%9.5f",sat[x].meanan);
	CopyString(string,line2,43,50);

	sprintf(string,"%12.9f",sat[x].meanmo);
	CopyString(string,line2,52,62);

	sprintf(string,"%5lu",sat[x].orbitnum);
	CopyString(string,line2,63,67);

	/* Compute and insert checksum for line 1 and line 2 */

	for (i=0, sum=0; i<=67; sum+=val[(int)line1[i]], i++);

	line1[68]=(sum%10)+'0';

	for (i=0, sum=0; i<=67; sum+=val[(int)line2[i]], i++);

	line2[68]=(sum%10)+'0';

	line1[69]=0;
	line2[69]=0;

	strcpy(sat[x].line1,line1);
	strcpy(sat[x].line2,line2);
}

char ReadDataFiles()
{
	/* This function reads "predict.qth", "predict.tle", and
	   (optional) "predict.db" files into memory.  Return
	   values are as follows:

	   0 : No files were loaded
	   1 : Only the qth file was loaded
	   2 : Only the tle file was loaded
	   3 : Both files were loaded successfully */

	FILE *fd;
	long catnum;
	unsigned char dayofweek;
	int x=0, y, entry=0, max_entries=10, transponders=0;
	char flag=0, match, name[80], line1[80], line2[80];

	fd=fopen(qthfile,"r");
	
	if (fd!=NULL)
	{
		fgets(qth.callsign,16,fd);
		qth.callsign[strlen(qth.callsign)-1]=0;
		fscanf(fd,"%lf", &qth.stnlat);
		fscanf(fd,"%lf", &qth.stnlong);
		fscanf(fd,"%d", &qth.stnalt);
		fscanf(fd,"%f",&qth.utc_offset);
		fclose(fd);

		obs_geodetic.lat=qth.stnlat*deg2rad;
		obs_geodetic.lon=-qth.stnlong*deg2rad;
		obs_geodetic.alt=((double)qth.stnalt)/1000.0;
		obs_geodetic.theta=0.0;

		flag=1;
	}

	fd=fopen(tlefile,"r");

	if (fd!=NULL)
	{
		while (x<24 && feof(fd)==0)
		{
			/* Initialize variables */

			name[0]=0;
			line1[0]=0;
			line2[0]=0;

			/* Read element set */

			fgets(name,75,fd);
			fgets(line1,75,fd);
			fgets(line2,75,fd);

			if (KepCheck(line1,line2) && (feof(fd)==0))
			{
				/* We found a valid TLE! */

				/* Some TLE sources left justify the sat
				   name in a 24-byte field that is padded
				   with blanks.  The following lines cut
				   out the blanks as well as the line feed
				   character read by the fgets() function. */
 
				y=strlen(name);

				while (name[y]==32 || name[y]==0 || name[y]==10 || name[y]==13 || y==0)
				{
					name[y]=0;
					y--;
				}
				
				/* Copy TLE data into the sat data structure */

				strncpy(sat[x].name,name,24);
				strncpy(sat[x].line1,line1,69);
				strncpy(sat[x].line2,line2,69);

				/* Update individual parameters */

				InternalUpdate(x);

				x++;
			}
		}

		fclose(fd);
		flag+=2;
		resave=0;

		/* Load satellite database file */

		fd=fopen(dbfile,"r");

		if (fd!=NULL)
		{
			database=1;

			fgets(line1,40,fd);

			while (strncmp(line1,"end",3)!=0 && line1[0]!='\n' && feof(fd)==0)
			{
				/* The first line is the satellite
				   name which is ignored here. */

				fgets(line1,40,fd);
				sscanf(line1,"%ld",&catnum);

				/* Search for match */

				for (y=0, match=0; y<24 && match==0; y++)
				{
					if (catnum==sat[y].catnum)
						match=1;
				}

				if (match)
				{
					transponders=0;
					entry=0;
					y--;
				}

				fgets(line1,40,fd);

				if (match)
				{
					if (strncmp(line1,"No",2)!=0)
					{
						sscanf(line1,"%lf, %lf",&sat_db[y].alat, &sat_db[y].alon);
						sat_db[y].squintflag=1;
					}

					else
						sat_db[y].squintflag=0;
				}

				fgets(line1,80,fd);

				while (strncmp(line1,"end",3)!=0 && line1[0]!='\n' && feof(fd)==0)
				{
					if (entry<max_entries)
					{
						if (match)
						{
							if (strncmp(line1,"No",2)!=0)
							{
								line1[strlen(line1)-1]=0;
								strcpy(sat_db[y].transponder_name[entry],line1);
							}
							else
								sat_db[y].transpond