/* "eph.c" star/planet celestial navigation program August 30, 1989 */
// This program is copyright (c) 2016, P. Lutus and is released
// under the GPL (http://www.gnu.org/licenses/gpl-3.0.en.html).
/* Most recent modification: 03.21.2016 fix segfaulting error */
#include <stdio.h>
#include <unistd.h>
#include <time.h>
#include <math.h>
#include <string.h>
#define char_bell 7
#define char_bs 8
#define char_fs 21
#define char_del 127
#define char_nl 10
#define char_cr 13
#define char_cz 26
#define cls() myputs("\033[H\033[J")
#define cleol() myputs("\033[K")
#define gotoxy(x,y) printf("%c[%d;%dH",27,y,x)
#define dsr() printf("\033[6n")
#define cpr(s,x,y) sscanfptr = sscanf(s,"\033[%d;%dR",y,x)
#define home() myputs("\033[H")
#define normal() myputs("\033[0m")
#define inverse() myputs("\033[7m")
#define toupper(c) ((c >= 'a') && (c <= 'z')?c-32:c)
#define tolower(c) ((c >= 'A') && (c <= 'Z')?c+32:c)
#define isnum(c) (((c >= '0') && (c <= '9')) || (c == '.'))
#define isalpha(c) (((c >= 'A') && (c <= 'Z')) || ((c >= 'a') && (c <= 'z')))
#define sgn(x) ((x > 0)?1:(x < 0)?-1:0)
#define PI 3.141592653589793
#define PI2 6.283185307179586
#define PI4 12.56637061435917
#define PD2 1.570796326794897
#define DTOR 1.74532925199433e-2
#define RTOD 5.729577951308232e1
#define ASTUNIT 9.2957130e7
const int buflen = 128;
char inbuf[buflen];
char temp[buflen];
char lastin[2][buflen];
char *starstrings[] = {
"acamar 3.1 315.6232 -0.00942 -40.3847 0.004",
"achernar 0.6 335.7575 -0.00917 -57.3374 0.005",
"acrux 1.1 173.6225 -0.0138 -62.9899 -0.0055",
"adhara 1.6 255.5374 -0.00983 -28.9463 -0.0014",
"aldebaran 1.1 291.3032 -0.01425 16.4688 0.002",
"alioth 1.7 166.7119 -0.0108 56.0672 -0.0053",
"alkaid 1.9 153.3111 -0.0097 49.4103 -0.005",
"alnair 2.2 28.2531 -0.0156 -47.0563 0.0048",
"alnilam 1.8 276.1968 -0.0126 -1.2157 0.0006",
"alphard 2.2 218.3453 -0.0122 -8.5739 -0.004",
"alphecca 2.3 126.5376 -0.0105 26.7818 -0.0033",
"alpheratz 2.2 358.1578 -0.0128 28.9814 0.0055",
"altair 0.9 62.5546 -0.01217 8.8171 0.00267",
"ankaa 2.4 353.6739 -0.0123 -42.4132 0.0053",
"antares 1.2 112.9507 -0.0153 -26.3876 -0.00217",
"arcturus 0.2 146.3103 -0.0113 19.2857 -0.00517",
"atria 1.9 108.3565 -0.026 -68.9915 -0.00175",
"avior 1.7 234.4704 -0.0051 -59.4471 -0.0032",
"bellatrix 1.7 278.9822 -0.0133 6.3307 0.0008",
"betelgeuse 0.6 271.4740 -0.0134 7.4026 0.0002",
"canopus -0.9 264.1210 -0.0056 -52.6869 -0.0006",
"capella 0.2 281.1924 -0.0183 45.9774 0.0009",
"deneb 1.3 49.8092 -0.0084 45.2110 0.0036",
"denebola 2.2 182.9871 -0.0127 14.6819 -0.0055",
"diphda 2.2 349.3257 -0.0125 -18.0951 0.0054",
"dubhe 2.0 194.3736 -0.0153 61.8572 -0.0054",
"elnath 1.8 278.7392 -0.0157 28.5900 0.0008",
"eltanin 2.4 90.9631 -0.0058 51.4931 -0.0001",
"enif 2.5 34.1954 -0.0122 9.7850 0.0045",
"fomalhaut 1.3 15.8601 -0.0138 -29.7264 0.0053",
"gacrux 1.6 172.4811 -0.0138 -57.0025 -0.0055",
"gienah 2.8 176.3022 -0.0128 -17.4326 -0.0055",
"hadar 0.9 149.3918 -0.0176 -60.2775 -0.0048",
"hamal 2.2 328.4849 -0.014 23.3688 0.0047",
"kausastralis 2.0 84.2844 -0.0164 -34.3935 -0.0006",
"kochab 2.2 137.3182 0.0007 74.2374 -0.0041",
"markab 2.6 14.0554 -0.0124 15.0996 0.0053",
"menkar 2.8 314.6885 -0.013 4.0117 0.0039",
"menkent 2.3 148.6199 -0.0146 -36.2728 -0.0048",
"miaplacidus 1.8 221.7482 -0.0028 -69.6374 -0.0041",
"mirfak 1.9 309.2719 -0.0178 49.7907 0.0035",
"nunki 2.1 76.4899 -0.0154 -26.3201 0.0013",
"peacock 2.1 53.9778 -0.0196 -56.7979 0.0033",
"pollux 1.2 243.9731 -0.0152 28.0732 -0.0024",
"procyon 0.5 245.4326 -0.013 5.2746 -0.0026",
"rasalhague 2.1 96.4954 -0.0115 12.5754 -0.0007",
"regulus 1.3 208.1699 -0.0133 12.0632 -0.00492",
"rigel 0.3 281.6028 -0.012 -8.2256 0.0011",
"rigilkentaurus 0.1 140.4333 -0.017 -60.7521 -0.004",
"sabik 2.6 102.6886 -0.0143 -15.6999 -0.0012",
"schedar 2.5 350.1526 -0.0142 56.4293 0.0054",
"shaula 1.7 96.9326 -0.0169 -37.0886 -0.0008",
"sirius -1.6 258.9308 -0.0109 -16.6907 -0.0014",
"spica 1.2 158.9617 -0.0131 -11.0578 -0.0051",
"suhail 2.2 223.1813 -0.009 -43.3539 -0.004",
"vega 0.1 80.9324 -0.0084 38.7667 0.001",
"zubenelgenubi 2.9 137.5535 -0.0138 -15.9592 -0.0041",
""
};
struct STARS {
char name[128];
double magn;
double semidiam;
double dist;
double sha;
double shacor;
double decl;
double declcor;
};
struct STARS startable[70];
struct COMPLX {
double rad;
double lat;
double lng;
double x;
double y;
double z;
};
struct COMPLX vals[8],loc1,loc2;
struct mytm {
double tm_sec;
double tm_min;
double tm_hour;
double tm_mday;
double tm_mon;
double tm_year;
double tm_wday;
double tm_yday;
double tm_isdst;
};
struct mytm tvals[8];
struct COMPLX here;
struct mytm datime;
double gmtdiff_s;
double gmtdiff_h;
double now;
double mag_dev;
double gha_a;
double horiz = 0.0;
double mag_lim = 2.0;
double eye_ht = 6;
double eye_ht_corr;
double speed;
double bearing;
double timtbl[4];
int ptrtbl[4];
char splitstr[12][128];
char *getsptr;
int sscanfptr;
int useloctm = 0;
int comline = 0;
char tzlbl[8];
int maxstars;
void myputs(char *s)
{
printf("%s",s);
/* char *p;
p = s-1;
while(*(++p));
write(1,s,p-s); */
}
double myacos(double x)
{
if(fabs(x) < 1.0)
x = acos(x);
return(x);
}
double myatan2(double a, double b)
{
if((a != 0.0) || (b != 0.0))
a = atan2(a,b);
return(a);
}
char *mygets(char *s,int len)
{
char *p = NULL;
if(!comline)
p = fgets(s,len,stdin);
return(p);
}
double mdy_sect(struct mytm p)
{
double r;
if(p.tm_year > 1900)
p.tm_year -= 1900;
p.tm_mon++;
if(p.tm_mon < 4)
{
p.tm_mon += 12;
p.tm_year -= 1;
}
r = p.tm_mday + floor(p.tm_mon * 30.6001) + (p.tm_year * 365.25) - 63;
r = floor(r);
r = (r * 24) + p.tm_hour;
r = (r * 60) + p.tm_min;
r = (r * 60) + p.tm_sec;
return(r);
}
struct mytm sect_mdy(double a)
{
struct mytm r;
r.tm_sec = fmod(a,60.0);
a = floor(a/60.0);
r.tm_min = fmod(a,60.0);
a = floor(a/60.0);
r.tm_hour = fmod(a,24.0);
a = floor(a/24.0);
a += 63;
r.tm_year = floor((a -122.1) / 365.25);
r.tm_mon = floor((a - floor(365.25 * r.tm_year)) / 30.6001);
r.tm_mday = a - floor(365.25 * r.tm_year);
r.tm_mday -= floor(30.6001 * r.tm_mon);
if(r.tm_mon < 14)
r.tm_mon -= 1;
else
r.tm_mon -= 13;
if (r.tm_mon <= 2)
r.tm_year += 1;
r.tm_wday = a / 7.0;
r.tm_wday = floor(7.0 * (r.tm_wday - floor(r.tm_wday)) + .5);
r.tm_year += 1970;
return(r);
}
double fpavals[] = { /* first point of aries, 1980 - 1999 */
98.8256,
99.5713,
99.3317,
99.0926,
98.8540,
99.6017,
99.3641,
99.1268,
98.8897,
99.6382,
99.4008,
99.1631,
98.9250,
99.6719,
99.4326,
99.1929,
98.9529,
99.6982,
99.4579,
99.2177
};
double meananom[] = { /* solar mean anomaly, 1980 - 1999 */
-3.7737,
-3.0452,
-3.3020,
-3.5583,
-3.8140,
-3.0836,
-3.3383,
-3.5927,
-3.8470,
-3.1157,
-3.3702,
-3.6251,
-3.8804,
-3.1507,
-3.4071,
-3.6640,
-3.9212,
-3.1930,
-3.4505,
-3.7078
};
double solperi[] = { /* sun's perihelion point, 1980 - 1999 */
77.4006,
77.3835,
77.3663,
77.3491,
77.3320,
77.3148,
77.2976,
77.2805,
77.2633,
77.2461,
77.2289,
77.2118,
77.1946,
77.1774,
77.1603,
77.1431,
77.1260,
77.1087,
77.0916,
77.0744
};
/* solar position in GHA form, so GHA is subtracted
before return to main program, where it is added again (sigh) */
struct COMPLX getsolpos(struct mytm datq,struct COMPLX r)
{
struct mytm rt;
double yd,dt,tm,m,ghaa;
dt = mdy_sect(datq);
rt = datq;
rt.tm_mon = 1;
rt.tm_mday = 1;
rt.tm_hour = 0;
rt.tm_min = 0;
rt.tm_sec = 0;
yd = mdy_sect(rt); /* get year day */
yd = dt - yd;
yd = floor(yd / 86400.0) + 1;
tm = datq.tm_hour + (datq.tm_min / 60.0) + (datq.tm_sec / 3600.0);
ghaa = fpavals[((int)datq.tm_year - 80)]
+ (.985647 * (yd + (tm / 24.0))) + (15 * tm);
ghaa *= DTOR;
ghaa = fmod(ghaa+PI4,PI2);
m = (.985647 * (yd + (tm / 24.0))) + meananom[((int)datq.tm_year - 80)];
r.lng = m + (1.9160 * sin(m * DTOR)) + (0.02 * sin(m * 2 * DTOR));
r.lng -= solperi[((int)datq.tm_year - 80)];
r.lng *= DTOR;
r.lng = fmod(r.lng+PI4,PI2);
r.lat = asin(0.3978 * sin(r.lng));
dt = atan(0.9175 * tan(r.lng));
if(dt < 0.0) dt += PI;
if(r.lng >= PI) dt += PI;
r.lng = (m + (tm * 15)) * DTOR;
r.lng -= dt;
r.lng -= ((solperi[((int)datq.tm_year - 80)] + 180.0) * DTOR);
r.lng -= ghaa;
r.lng = fmod(r.lng+PI4,PI2);
r.lng = PI2 - r.lng;
return(r);
}
/* import planet ephemeris */
struct HMS
{
unsigned hr,mn,sc;
};
double hms_radians(struct HMS hms)
{
double digit;
digit = hms.hr + (hms.mn / 60.0) + (hms.sc / 3600.0);
digit *= DTOR;
return(digit);
}
char *planet_name[] ={
"sun",
"mercury",
"venus",
"mars",
"jupiter",
"saturn",
"uranus",
"neptune",
"pluto"
};
double orbital_period[] = {
365.2596, /* Earth */
87.9693, /* Mercury */
224.7009, /* Venus */
686.9796, /* Mars */
4332.1248, /* Jupiter */
10825.863, /* Saturn */
30676.15, /* Uranus */
59911.13, /* Neptune */
90824.2 /* Pluto */
};
double eccentricity[] = {
.016755, /* Earth */
.205636, /* Mercury */
.006759, /* Venus */
.093348, /* Mars */
.048061, /* Jupiter */
.050822, /* Saturn */
.047552, /* Uranus */
.006608, /* Neptune */
.253364 /* Pluto */
};
struct HMS ascending_node[] = {
0, 0, 0, /* Earth */
48, 9, 4, /* Mercury */
76, 32, 42,/* Venus */
49, 26, 35, /* Mars */
100, 20, 20, /* Jupiter */
113, 32, 20, /* Saturn */
73, 59, 17, /* Uranus */
131, 37, 34, /* Neptune */
110, 12, 58 /* Pluto */
};
struct HMS perihelion[] = {
102, 42, 22, /* Earth */
77, 13, 19, /* Mercury */
131, 29, 24, /* Venus */
335, 43, 16, /* Mars */
15, 23, 56, /* Jupiter */
93, 29, 13, /* Saturn */
177, 7, 23, /* Uranus */
354, 40, 12, /* Neptune */
224, 15, 0 /* Pluto */
};
struct HMS inclination[] = {
0, 0, 0, /* Earth */
7, 0, 17, /* Mercury */
3, 23, 40, /* Venus */
1, 50, 59, /* Mars */
1, 18, 19, /* Jupiter */
2, 29, 8, /* Saturn */
0, 46, 27, /* Uranus */
1, 46, 15, /* Neptune */
17, 7, 56 /* Pluto */
};
struct HMS epoch_longitude[] = {
35, 32, 32, /* Earth */
242, 6, 54, /* Mercury */
298, 45, 24, /* Venus */
329, 44, 5, /* Mars */
293, 28, 58, /* Jupiter */
224, 21, 44, /* Saturn */
248, 5, 3, /* Uranus */
271, 32, 56, /* Neptune */
216, 55, 28 /* Pluto */
};
double distance[] = {
.999994, /* Earth */
.387098, /* Mercury */
.723330, /* Venus */
1.523712, /* Mars */
5.20270, /* Jupiter */
9.57542, /* Saturn */
19.2998, /* Uranus */
30.2813, /* Neptune */
39.7138 /* Pluto */
};
double albedo[] = {
.39, /* Earth */
.06, /* Mercury */
.72, /* Venus */
.16, /* Mars */
.70, /* Jupiter */
.75, /* Saturn */
.90, /* Uranus */
.82, /* Neptune */
.14 /* Pluto */
};
double radius[] = { /* miles */
432560.0, /* Sun */
1515.0, /* Mercury */
3760.0, /* Venus */
2108.4, /* Mars */
44362.0, /* Jupiter */
37280.0, /* Saturn */
15800.0, /* Uranus */
15100.0, /* Neptune */
930.0 /* Pluto */
};
double epoch = 30981; /* oct 27 1984 */
struct COMPLX pol_rect(struct COMPLX pol)
{
struct COMPLX r;
double cp2;
cp2 = cos(pol.lat);
r.x = pol.rad * cos(pol.lng) * cp2;
r.y = pol.rad * sin(pol.lng) * cp2;
r.z = pol.rad * sin(pol.lat);
return(r);
}
struct COMPLX rect_pol(struct COMPLX r)
{
struct COMPLX pol;
pol.lng = myatan2(r.y,r.x);
pol.rad = hypot(r.y,r.x);
if(pol.lng < 0) pol.lng = PI2 + pol.lng;
pol.lat = myatan2(r.z,pol.rad);
pol.rad = hypot(r.z,pol.rad);
return(pol);
}
struct COMPLX cd_position(double cd,int n)
{
double a,ec,e,oe,qe;
int i;
struct COMPLX pol;
struct COMPLX r;
a = (cd - epoch)/orbital_period[n];
a -= floor(a);
a *= PI2;
a += hms_radians(epoch_longitude[n]);
a -= hms_radians(perihelion[n]);
a = (a < 0)?PI2 + a:a;
ec = eccentricity[n];
e = a;
i = 0;
do
{
oe = e;
e = a + ec * sin(e); /* compute eccentric anomaly the normal way */
if (i > 20)
{
qe = a + ec * sin(e); /* probably oscillating now ... */
e = (e + qe) * .5; /* take average of 2 extremes */
}
}
while((fabs(oe - e) > .00001) && (i++ < 100)); /* eventually give up */
a = sqrt((1 + ec)/(1 - ec));
a = 2 * atan(a * tan(e * .5));
pol.rad = distance[n] * (1 - ec * cos(e));
a += hms_radians(perihelion[n]);
pol.lng = a;
e = a - hms_radians(ascending_node[n]);
ec = hms_radians(inclination[n]);
pol.lat = sin(e);
pol.lat *= ec;
r = pol_rect(pol);
return(r);
}
struct COMPLX right_ascension(struct COMPLX arg)
{
double r,ang;
r = hypot(arg.z,arg.y);
ang = myatan2(arg.z,arg.y);
ang += .40927970959;
arg.z = r * sin(ang);
arg.y = r * cos(ang);
return(arg);
}
void planet_table(double cd,int p,struct mytm datim)
{
int n,a,b;
double helio_dist,helio_angle,earth_dist,magnitude;
struct COMPLX cart,pol;
static struct COMPLX earth;
static double oldcd = 0.0;
cd /= 86400.0;
if(cd != oldcd)
{
earth = cd_position(cd,0);
earth.x = -earth.x;
earth.y = -earth.y;
earth.z = -earth.z;
cart = right_ascension(earth);
pol = rect_pol(cart);
earth_dist = pol.rad;
if((datim.tm_year >= 80) && (datim.tm_year <= 99))
pol = getsolpos(datim,pol);
startable[60].sha = PI2 - pol.lng;
startable[60].decl = pol.lat;
startable[60].magn = -26.8;
startable[60].dist = earth_dist * ASTUNIT;
startable[60].shacor = 0;
startable[60].declcor = 0;
startable[60].semidiam = asin(radius[0]/startable[60].dist);
oldcd = cd;
}
a = 1;
b = 8;
if(p >= 0)
{
a = p-60;
b = p-60;
}
for (n = a;n <= b;n++)
{
if(n)
{
cart = cd_position(cd,n);
pol = rect_pol(cart);
helio_dist = pol.rad;
helio_angle = pol.lng;
cart.x += earth.x;
cart.y += earth.y;
cart.z += earth.z;
cart = right_ascension(cart);
pol = rect_pol(cart);
earth_dist = pol.rad;
helio_angle -= pol.lng;
startable[n+60].sha = PI2 - pol.lng;
startable[n+60].decl = pol.lat;
startable[n+60].dist = earth_dist * ASTUNIT;
startable[n+60].shacor = 0;
startable[n+60].declcor = 0;
startable[n+60].semidiam = asin(radius[n]/startable[n+60].dist);
magnitude = 2.8048e-1; /* relative sun brightness */
magnitude *= (radius[n] * radius[n]);
magnitude /= (helio_dist * helio_dist);
magnitude *= albedo[n];
magnitude /= (earth_dist * earth_dist);
magnitude *= 1.7e-5;
magnitude *= ((1.0 + cos(helio_angle)) / 2.0);
magnitude = -2.5 * (log10(magnitude));
startable[n+60].magn = magnitude;
}
} /* for */
}
/* end planet epehemeris import */
void localt(int n)
{
if(n)
useloctm ^= 1;
if(useloctm)
strcpy(tzlbl,*tzname);
else
strcpy(tzlbl,"GMT");
}
void locase(char *s)
{
while(*s = tolower(*s))
s++;
}
/* #ifndef MSDOS
double fmod(a,b)
double a,b;
{
a /= b;
a -= floor(a);
a *= b;
return(a);
}
#endif */
struct COMPLX rect_to_pol(struct COMPLX p)
{
p.lng = myatan2(p.x,p.z);
p.rad = hypot(p.x,p.z);
p.lat = myatan2(p.y,p.rad);
return(p);
}
struct COMPLX comp_pr(struct COMPLX b,struct COMPLX a)
{
double dlo,cdlo,sal,cal;
dlo = a.lng - b.lng;
cdlo = cos(dlo);
sal = sin(a.lat);
cal = cos(a.lat);
a.rad = myacos((sal * sin(b.lat)) + (cal * cos(b.lat) * cdlo));
a.rad *= RTOD * 60;
a.lat = myatan2(sin(dlo),(cal * tan(b.lat) - sal * cdlo));
if (a.lat < 0) a.lat = PI2 + a.lat;
return(a);
}
struct COMPLX comp_pa(struct COMPLX b,struct COMPLX a)
{
a = comp_pr(b,a);
a.rad = 90.0 - (a.rad / 60.0);
return(a);
}
struct COMPLX comp_rp(struct COMPLX b,struct COMPLX a)
{
struct COMPLX c;
double r,sr,ang;
r = b.rad / (RTOD * 60.0);
sr = sin(r);
c.x = -sin(b.lat) * sr; /* create rect. of dist. & hdg. */
c.y = cos(b.lat) * sr;
c.z = cos(r);
r = hypot(c.z,c.y);
ang = myatan2(c.y,c.z) + a.lat; /* rotate y,z to orig. lat. */
c.z = r * cos(ang);
c.y = r * sin(ang);
c = rect_to_pol(c);
c.lng += a.lng; /* add long. */
return(c);
}
void ztest(double *x)
{
if(*x == 0.0)
*x = 1.0e-15;
}
void conv_circles(double lat,double lon,double zen,double *a, double *b,double *c,double *d, double *k)
{
*a = cos(lon) * cos(lat);
*b = -sin(lon) * cos(lat);
*c = sin(lat);
*d = cos(zen);
*k = *d * (*a * *a + *b * *b + *c * *c);
}
double rad_dist(double a,double b,double c,double d)
{
return(((a-b)*(a-b)) + ((c-d)*(c-d)));
}
struct COMPLX do_circles(struct COMPLX aa,struct COMPLX bb)
{
struct COMPLX rr;
double a1,b1,c1,d1,k1;
double a2,b2,c2,d2,k2;
double r,s,t,l,m,n,p,u,v,w,f,g,h,x,y,z,dd,ee;
aa.rad = PD2 - aa.rad;
bb.rad = PD2 - bb.rad;
if(aa.lat == bb.lat)
aa.lat += 1e-10;
conv_circles(aa.lat,aa.lng,aa.rad,&a1,&b1,&c1,&d1,&k1);
conv_circles(bb.lat,bb.lng,bb.rad,&a2,&b2,&c2,&d2,&k2);
ztest(&b1);
ztest(&b2);
ztest(&c1);
ztest(&c2);
r = a1*c2/c1-a2;
s = b1*c2/c1-b2;
t = k1*c2/c1-k2;
m = t/r;
n = -t/s;
p = (b1*t/s-a1*t/r)/c1;
l = sqrt(m*m + n*n + p*p);
ztest(&l);
m /= l;
n /= l;
p /= l;
u = a2*p/c2-m;
v = b2*p/c2-n;
w = k2*p/c2;
ztest(&r);
ztest(&v);
f = (t*v/s-w)/(r*v/s-u);
g = (t-r*f)/s;
h = (k1-a1*f-b1*g)/c1;
dd = sqrt(f*f + g*g + h*h);
if((dd*dd) <= 1.0) /* if circles intersect */
{
rr.z = 0;
ee = sqrt(1.0-dd*dd);
/* first result */
x = f + ee*m;
y = g + ee*n;
z = h + ee*p;
rr.lat = asin(z);
rr.lng = myatan2(-y,x);
/* second result */
x = f - ee*m;
y = g - ee*n;
z = h - ee*p;
rr.x = asin(z);
rr.y = myatan2(-y,x);
}
else
rr.z = -1;
return(rr);
}
void disp_deg_min(double v,int f)
{
int q_d,q_m,vs;
double q_m2;
vs = (v < 0)?-1:1;
v *= RTOD;
v = fabs(v) + .00008;
q_d = (int) v;
q_m = (int) ((v - q_d) * 6000.0);
q_m2 = q_m * 1e-2;
if(f)
q_d *= vs;
printf("%3d deg %5.02lf min",q_d,q_m2);
}
void disp_hms(double v)
{
int q_d,q_m,q_s;
if(useloctm)
{
v -= gmtdiff_h;
if (v < 0)
v += 24;
if(v > 24)
v -= 24;
}
v = fabs(v) + .000138;
q_d = (int) v;
v = (v - q_d) * 60.0;
q_m = (int) v;
v = (v - q_m) * 60.0;
q_s = (int) v;
printf("%02d:%02d:%02d %s",q_d,q_m,q_s,tzlbl);
}
void disp_lat_lng(struct COMPLX q)
{
int lat_s,lng_s;
int lat_d,lng_d;
int lat_m,lng_m;
double lat_m2,lng_m2;
q.lat *= RTOD;
q.lng *= RTOD;
if(q.lng > 180.0)
q.lng -= 360.0;
lat_s = (q.lat >= 0);
lng_s = (q.lng >= 0);
q.lat = fabs(q.lat) + .000008;
q.lng = fabs(q.lng) + .000008;
lat_d = (int) q.lat;
lat_m = (int) ((q.lat - lat_d) * 6000.0);
lat_m2 = lat_m * 1e-2;
lng_d = (int) q.lng;
lng_m = (int) ((q.lng - lng_d) * 6000.0);
lng_m2 = lng_m * 1e-2;
printf("lat %3d deg %5.02lf min %c lng %3d deg %5.02lf min %c"
,lat_d,lat_m2,(lat_s)?'N':'S',lng_d,lng_m2,(lng_s)?'W':'E');
}
void print_datime(struct mytm t)
{
double dt;
if(useloctm)
{
dt = mdy_sect(t);
t = sect_mdy(dt-gmtdiff_s);
}
printf("%02.0lf:%02.0lf:%02.0lf %s %02.0lf/%02.0lf/%04.0lf"
,t.tm_hour,t.tm_min,t.tm_sec,tzlbl
,t.tm_mon,t.tm_mday,t.tm_year);
}
void split(char *s)
{
int i;
for(i = 0; i < 12;i++)
splitstr[i][0] = 0;
sscanfptr = sscanf(s,
"%s %s %s %s %s %s %s %s %s %s %s %s"
,splitstr[0],splitstr[1],splitstr[2],splitstr[3]
,splitstr[4],splitstr[5],splitstr[6],splitstr[7]
,splitstr[8],splitstr[9],splitstr[10],splitstr[11]);
}
int isdelim(char *s,int c)
{
int result = 0;
do
result = (*s == c);
while((*(++s)) && (!result));
return(result);
}
int llscan(int i,double *q)
{
double x;
int c;
*q *= RTOD;
if(*(splitstr+i)[0])
{
sscanf(*(splitstr+i),"%lf",q);
i++;
}
if(*(splitstr+i)[0])
{
sscanf(*(splitstr+i),"%lf",&x);
*q += (x/60.0);
i++;
}
if(*(splitstr+i)[0])
{
c = toupper(*(splitstr+i)[0]);
if ((c == 'S') || (c == 'N') || (c == 'E') || (c == 'W'))
{
if ((c == 'S') || (c == 'E'))
*q = -*q;
i++;
}
}
*q *= DTOR;
return(i);
}
int limbscan(int i,int *q)
{
int c;
c = toupper(*(splitstr+i)[0]);
if((c == 'L') || (c == 'U'))
{
*q = (c == 'U');
i++;
}
else *q = 0;
return(i);
}
int getdate(int i,struct mytm *t)
{
struct mytm q;
q = *t;
if(isdelim(splitstr[i],'/'))
{
sscanfptr = sscanf(splitstr[i],"%lf/%lf/%lf"
,&q.tm_mon,&q.tm_mday,&q.tm_year);
i++;
}
*t = q;
return(i);
}
int gettime(int i,struct mytm *t)
{
struct mytm q;
q = *t;
if(isdelim(splitstr[i],':'))
{
sscanfptr = sscanf(splitstr[i],"%lf:%lf:%lf"
,&q.tm_hour,&q.tm_min,&q.tm_sec);
i++;
}
*t = q;
return(i);
}
struct mytm getdatime(struct mytm *t)
{
int i = 0;
unsigned long tm;
double dtm;
if(!comline)
printf("Enter %s Time & date as [hh:mm:ss] [mm/dd/yy] (N=now):",tzlbl);
getsptr = mygets(inbuf,buflen);
if(inbuf[0])
{
if(toupper(inbuf[0]) == 'N')
{
tm = time(NULL);
dtm = tm;
*t = sect_mdy(dtm);
}
else
{
if(useloctm)
{
dtm = mdy_sect(*t);
*t = sect_mdy(dtm-gmtdiff_s);
}
split(inbuf);
i = gettime(i,t);
i = getdate(i,t);
if(useloctm)
{
dtm = mdy_sect(*t);
*t = sect_mdy(dtm+gmtdiff_s);
}
}
}
}
struct COMPLX getlatlng(struct COMPLX *x,int prompt)
{
int i = 0;
double a;
if(prompt)
{
if(!comline)
myputs(
"Enter estimated position as (lat) dd mm.mm [N/S] (lng) ddd mm.mm [E/W]\n:");
}
getsptr = mygets(inbuf,buflen);
split(inbuf);
a = x->lat;
i = llscan(i,&a);
x->lat = a;
a = x->lng;
i = llscan(i,&a);
x->lng = a;
}
double getghaa(struct mytm datq)
{
struct mytm r;
double cf = 99.2124; /* an average aries GHA in case no year value */
double gha,th,yd,dt;
dt = mdy_sect(datq);
r = datq;
r.tm_mon = 1;
r.tm_mday = 1;
r.tm_hour = 0;
r.tm_min = 0;
r.tm_sec = 0;
yd = mdy_sect(r); /* get year day */
yd = dt - yd;
yd = floor(yd / 86400.0) + 1;
if ((datq.tm_year >= 80) && (datq.tm_year <= 99))
cf = fpavals[((int)datq.tm_year - 80)];
th = datq.tm_hour + (datq.tm_min / 60.0) + (datq.tm_sec / 3600.0);
gha = cf + (.985647 * (yd + (th/24.0))) + (15 * th);
gha = fmod(gha,360.0);
gha *= DTOR;
return(gha);
}
double sight_corr(double x,int i,int uprlimb) /* eye height, parallax, limb, refraction */
{
double a,r;
r = -eye_ht_corr; /* sextant eye height correction */
if(startable[i].dist)
{
a = cos(x) * 3963; /* small angles mean large parallax */
a = asin(a/startable[i].dist); /* parallax angle */
r += a;
}
if(uprlimb)
r -= startable[i].semidiam; /* for upper limb */
else
r += startable[i].semidiam; /* for lower limb */
a = x + 5.23598775598e-2; /* perform standard refraction corr. */
a = atan(a * 12.0 * RTOD);
r += (2.821615624e-4 * tan(x - a));
return(r);
}
void liststars(int f,int p)
{
int i,j = 0,ds;
double cv,gha,dec,ghaa;
if(!comline)
{
cls();
printf(
"Objects brighter than selected magnitude limit (now %.01lf):\n\n"
,mag_lim);
}
cv = (now / 86400.0) - 29220.0;
cv /= 365.25;
ghaa = (f)?0.0:gha_a;
i = (p)?60:0;
while(startable[i].name[0])
{
if(p)
planet_table(now,i,datime);
if(startable[i].magn <= mag_lim)
{
gha = ghaa + (startable[i].sha + (startable[i].shacor * cv));
gha = fmod(gha,PI2);
dec = startable[i].decl + (startable[i].declcor * cv);
printf("%-16.16s mag %+5.01lf dec "
,startable[i].name,startable[i].magn);
ds = (dec < 0);
dec = fabs(dec);
disp_deg_min(dec,0);
printf(" %c",(ds)?'S':'N');
printf(" %s ",(f)?"sha":"gha");
disp_deg_min(gha,0);
myputs("\n");
if((!comline) && (j) && (!(j % 18)))
{
myputs("(press return):");
getsptr = mygets(inbuf,buflen);
}
j++;
}
i++;
}
if(!comline)
myputs("(press return):");
getsptr = mygets(inbuf,buflen);
}
void findstars(int p)
{
int i,j = 0;
struct COMPLX x;
double cv;
if(!comline)
{
cls();
printf(
"Objects brighter than selected magnitude limit (now %.01lf)\n"
,mag_lim);
printf(
"and above selected horizon limit angle (now %.01lf deg):\n\n"
,horiz * RTOD);
}
cv = (now / 86400.0) - 29220.0; /* data are epoch 1980 */
cv /= 365.25;
i = (p)?60:0;
while(startable[i].name[0])
{
if(p)
planet_table(now,i,datime);
x.lng = gha_a + (startable[i].sha + (startable[i].shacor * cv));
x.lng = fmod(x.lng,PI2);
x.lat = startable[i].decl + (startable[i].declcor * cv);
x = comp_pa(x,here);
x.lat += mag_dev;
x.rad *= DTOR;
x.rad -= sight_corr(x.rad,i,0); /* in reverse, assume lower limb */
if((x.rad >= horiz) && (startable[i].magn < mag_lim))
{
printf("%-16.16s mag %+5.01lf alt "
,startable[i].name,startable[i].magn);
disp_deg_min(x.rad,1);
myputs(" az ");
disp_deg_min(x.lat,0);
myputs("\n");
if((!comline) && (j) && (!(j % 18)))
{
myputs("(press return):");
getsptr = mygets(inbuf,buflen);
}
j++;
}
i++;
}
if(!comline)
myputs("(press return):");
getsptr = mygets(inbuf,buflen);
}
int srchname(char *str)
{
char *a,*b;
int i = 0,found = -1,p = 0;
while((found < 0) && ((startable[i].name[0]) || (!p)))
{
if(startable[i].name[0])
{
a = str;
b = startable[i].name;
while((*a) && (*b) && (*a == *b))
{
a++;
b++;
}
if(*a == 0) found = i;
i++;
}
else if(!p)
{
p++;
i = 60;
}
}
return(found);
}
void disp_fix(struct COMPLX c,int f)
{
if(f)
myputs("best result --> ");
else
myputs(" ");
disp_lat_lng(c);
myputs("\n");
}
void starfix()
{
int i = 0,j,k,uprlimb;
double dd,cv,ghaa,datemp;
struct COMPLX c,r;
r.lat = 0.0;
if(!comline)
{
cls();
myputs("Compute position by two sextant sightings.\n\n");
myputs(
"1. Greatest accuracy is achieved when two sightings take place at the same"
);
putc(char_nl,stdout);
myputs(
"time (within minutes), or the vessel is not in motion. If this is not the"
);
putc(char_nl,stdout);
myputs(
"case, accurate results require the entry of a good position estimate,"
);
putc(char_nl,stdout);
myputs(
"magnetic deviation, vessel speed and bearing (main menu options B - E)."
);
myputs("\n\n");
myputs(
"2. Greatest accuracy is obtained when the sun or stars are used for sights,"
);
putc(char_nl,stdout);
myputs(
"their positions are calculated with greater precision than the planets.\n\n"
);
}
while(i < 2)
{
if(!comline)
{
printf(
"Enter name of object %d, sextant altitude,\n",i+1);
printf(
"lower or upper limb (for sun or planets), time %s, date\n",tzlbl);
myputs("as name (alt) dd mm.mm [L/U] (time) hh:mm:ss (date) mm/dd/yy\n(type \"=\" to use last entry):");
}
getsptr = mygets(inbuf,buflen);
if(inbuf[0])
{
tvals[i] = datime;
if(useloctm)
{
datemp = mdy_sect(tvals[i]);
tvals[i] = sect_mdy(datemp-gmtdiff_s);
}
if((inbuf[0] == '=') && (inbuf[1] == 0) && (lastin[i][0]))
strcpy(inbuf,lastin[i]);
strcpy(lastin[i],inbuf);
split(inbuf);
getsptr = strcpy(temp,splitstr[0]);
j = 1;
j = llscan(j,&vals[i].rad);
j = limbscan(j,&uprlimb);
j = gettime(j,&tvals[i]);
j = getdate(j,&tvals[i]);
if(useloctm)
{
datemp = mdy_sect(tvals[i]);
tvals[i] = sect_mdy(datemp+gmtdiff_s);
}
locase(temp);
datemp = mdy_sect(tvals[i]);
timtbl[i] = datemp;
if((j = srchname(temp)) < 0) /* not found */
{
j = 58+i;
getsptr = strcpy(startable[j].name,temp);
startable[j].semidiam = 0;
if(!comline)
{
printf(
"\n\"%s\" not found in internal almanac table. Please enter\n",temp);
myputs(
"this object's declination and GHA for the time entered above\n");
myputs(
"as (decl) ddd mm.mm N/S (GHA) ddd mm.mm:");
}
vals[i].lat = 0;
vals[i].lng = 0;
getlatlng(&vals[i],0);
}
else
{
ghaa = getghaa(tvals[i]);
if(j >= 60)
planet_table(datemp,j,tvals[i]);
cv = (datemp / 86400.0) - 29220.0; /* data are epoch 1980 */
cv /= 365.25;
vals[i].lng = ghaa + (startable[j].sha + (startable[j].shacor * cv));
vals[i].lng = fmod(vals[i].lng,PI2);
vals[i].lat = startable[j].decl + (startable[j].declcor * cv);
}
ptrtbl[i] = j;
vals[i].rad += sight_corr(vals[i].rad,j,uprlimb);
i++;
}
else i = 8; /* quit */
}
if(i == 2)
{
if(!comline)
cls();
myputs("\nSelected objects, positions, and sextant altitudes:\n");
for(j = 0;j < i;j++)
{
k = ptrtbl[j];
printf("%d: %-16.16s "
,j+1,startable[k].name);
disp_lat_lng(vals[j]);
myputs("\nCorr. Sext. Alt. ");
disp_deg_min(vals[j].rad,0);
myputs(" at ");
print_datime(tvals[j]);
myputs("\n");
}
if(speed != 0.0)
{
if(now != timtbl[0])
{
dd = (timtbl[0] - now) / 3600.0; /* hours between pos and sight 1 */
c.rad = speed * dd; /* shift position of object along course */
c.lat = bearing - mag_dev;
loc1 = comp_rp(c,here);
}
else loc1 = here;
if(now != timtbl[1])
{
dd = (timtbl[1] - now) / 3600.0; /* hours between pos and sight 2 */
c.rad = speed * dd; /* shift position of object along course */
c.lat = bearing - mag_dev;
loc2 = comp_rp(c,here);
}
else loc2 = here;
c = comp_pr(loc1,vals[0]); /* radius for orig. pos. */
dd = c.rad;
c = comp_pr(loc2,vals[0]); /* estimated radius for new pos. */
if(dd != 0)
{
dd = c.rad / dd; /* ratio of old and new radii */
vals[0].rad = PD2 - ((PD2 - vals[0].rad) * dd);
}
}
else loc2 = here;
c = do_circles(vals[1],vals[0]);
if(c.z == 0)
{
if(rad_dist(c.lat,here.lat,c.lng,here.lng) < rad_dist(c.x,here.lat,c.y,here.lng))
{
r = c;
j = 0;
}
else
{
r.lat = c.x;
r.lng = c.y;
j = 1;
}
myputs(
"\nPossible positions at time of sighting 2:\n\n");
disp_fix(c,j == 0);
c.lat = c.x;
c.lng = c.y;
disp_fix(c,j == 1);
}
else
myputs(
"\nError: position circles do not intersect.\n");
if(!comline)
{
if(r.lat)
{
myputs("\nWant to replace estimated position with this result (Y/N):");
getsptr = mygets(inbuf,buflen);
if(toupper(inbuf[0]) == 'Y')
here = r;
}
else
{
myputs("\n(return):");
getsptr = mygets(inbuf,buflen);
}
}
}
}
double rshour(double l,double d,double subh)
{
double r;
r = sin(subh) - (sin(l) * sin(d));
r /= cos(l) * cos(d);
if(fabs(r) < 1.0)
r = (acos(r) * RTOD) / 15.0; /* expressed as delta hours */
else r *= 1000.0; /* +- error value */
return(r);
}
void rise_set(int p)
{
struct COMPLX q;
struct mytm t,u;
int i,j = 0;
double cv,ghaa,datemp,datempb,tval,setpt,rsa;
if(!comline)
{
cls();
printf(
"Objects brighter than selected magnitude limit (now %.01lf):\n\n"
,mag_lim);
}
i = (p)?60:0;
t = datime;
t.tm_hour = 0;
t.tm_min = 0;
t.tm_sec = 0;
u = t;
ghaa = getghaa(t);
datemp = mdy_sect(t);
cv = (datemp / 86400.0) - 29220.0; /* data are epoch 1980 */
cv /= 365.25;
while(startable[i].name[0])
{
if(p)
planet_table(datemp,i,t);
if(startable[i].magn <= mag_lim)
{
setpt = (i == 60)?-.8333:-.55; /* 50 min below for sun, 33 min others */
setpt *= DTOR;
q.lng = ghaa + (startable[i].sha + (startable[i].shacor * cv));
q.lng = fmod(q.lng,PI2);
q.lat = startable[i].decl + (startable[i].declcor * cv);
tval = ((here.lng - q.lng) / PI2) * 24.0;
if (tval < 0) tval += 24.0;
if(p)
{
u.tm_hour = tval;
datempb = mdy_sect(u);
planet_table(datempb,i,u);
q.lng = ghaa + startable[i].sha;
q.lng = fmod(q.lng,PI2);
q.lat = startable[i].decl;
tval = ((here.lng - q.lng) / PI2) * 24.0;
if (tval < 0) tval += 24.0;
}
tval *= .997269567;
tval = fmod(tval,24.0);
printf("%-16.16s mer. pass. ",startable[i].name);
disp_hms(tval);
rsa = rshour(here.lat,q.lat,setpt);
if(rsa >= 1000.0)
myputs(", always below horizon this date & loc.");
else if(rsa <= -1000.0)
myputs(", always above horizon this date & loc.");
else
{
myputs(", rise ");
cv = tval - rsa;
if(cv < 0.0)
cv += 24.0;
disp_hms(cv);
myputs(", set ");
cv = tval + rsa;
if(cv >= 24.0)
cv -= 24.0;
disp_hms(cv);
}
myputs("\n");
if((!comline) && (j) && (!(j % 18)))
{
myputs("(press return):");
getsptr = mygets(inbuf,buflen);
}
j++;
}
i++;
}
if(!comline)
myputs("(press return):");
getsptr = mygets(inbuf,buflen);
}
void noonsight()
{
struct COMPLX sp,ss;
struct mytm st;
double qt,ghaa,ssign,ssdeg;
int j = 0,uprlimb;
st = datime;
ss.rad = 0;
if(!comline)
{
cls();
myputs(
"Compute position by noon sun sight.\n\n");
myputs(
"Enter sextant altitude at meridian passage, whether sun was north or\n");
printf(
"south of vessel, whether upper or lower limb, %s time and date\n",tzlbl);
myputs(
"of meridian passage as\n");
myputs(
"(alt) dd mm.mm [N/S] (limb) [L/U] (time) hh:mm:ss (date) mm/dd/yy\n\n:");
}
getsptr = mygets(inbuf,buflen);
split(inbuf);
j = llscan(j,&ss.rad);
j = limbscan(j,&uprlimb);
if(useloctm)
{
qt = mdy_sect(st);
st = sect_mdy(qt-gmtdiff_s);
}
j = gettime(j,&st);
j = getdate(j,&st);
if(useloctm)
{
qt = mdy_sect(st);
st = sect_mdy(qt+gmtdiff_s);
}
qt = mdy_sect(st);
ghaa = getghaa(st);
planet_table(qt,60,st);
sp.lng = startable[60].sha + ghaa;
sp.lng = fmod(sp.lng,PI2);
sp.lat = startable[60].decl;
ssign = sgn(ss.rad);
ss.rad = fabs(ss.rad);
ss.rad += sight_corr(ss.rad,60,uprlimb);
ssdeg = ss.rad;
ss.rad *= RTOD;
ss.rad = (90.0 - ss.rad) * 60.0;
ss.rad *= ssign;
ss.lat = PI; /* south, .rad has -sign for north */
sp = comp_rp(ss,sp);
myputs("Corr. sext. alt. ");
disp_deg_min(ssdeg,0);
printf("\nsun %s of vessel, %s limb"
,(sgn(ss.rad) > 0)?"north":"south"
,(uprlimb)?"upper":"lower");
myputs(" at ");
print_datime(st);
myputs("\n");
myputs("vessel location: ");
disp_lat_lng(sp);
if(!comline)
{
myputs("\n\nWant to replace estimated position with this result (Y/N):");
getsptr = mygets(inbuf,buflen);
if(toupper(inbuf[0]) == 'Y')
here = sp;
}
}
void putdat()
{
FILE *fp;
fp = fopen("eph.dat","w");
if(fp != NULL)
{
fprintf(fp,"%lf %lf\n",here.lat * RTOD,here.lng * RTOD);
fprintf(fp,"%lf\n",mag_dev * RTOD);
fprintf(fp,"%lf\n",speed);
fprintf(fp,"%lf\n",bearing * RTOD);
fprintf(fp,"%lf\n",eye_ht);
fprintf(fp,"%lf\n",mag_lim);
fprintf(fp,"%lf\n",horiz * RTOD);
fprintf(fp,"%d\n",useloctm);
fclose(fp);
}
else myputs("unable to save program data.\n");
}
void getdat()
{
FILE *fp;
fp = fopen("eph.dat","r");
if(fp != NULL)
{
fgets(inbuf,120,fp);
sscanf(inbuf,"%lf %lf",&here.lat,&here.lng);
here.lat *= DTOR;
here.lng *= DTOR;
fgets(inbuf,120,fp);
sscanf(inbuf,"%lf", &mag_dev);
mag_dev *= DTOR;
fgets(inbuf,120,fp);
sscanf(inbuf,"%lf", &speed);
fgets(inbuf,120,fp);
sscanf(inbuf,"%lf", &bearing);
bearing *= DTOR;
fgets(inbuf,120,fp);
sscanf(inbuf,"%lf", &eye_ht);
fgets(inbuf,120,fp);
sscanf(inbuf,"%lf", &mag_lim);
fgets(inbuf,120,fp);
sscanf(inbuf,"%lf", &horiz);
horiz *= DTOR;
fgets(inbuf,120,fp);
sscanf(inbuf,"%d",&useloctm);
fclose(fp);
}
localt(0);
}
int menu()
{
int c;
cls();
myputs("Celestial Navigation Program (c) P. Lutus 1989-2005\n\n");
myputs("A. Enter time & date (now ");
print_datime(datime);
myputs(")\n");
myputs("B. Enter est. position (now ");
disp_lat_lng(here);
myputs(")\n");
printf("C. Enter local magnetic deviation (now %.01lf deg)\n"
,mag_dev * RTOD);
printf("D. Enter vessel speed (now %.01lf knots)\n",speed);
myputs("E. Enter vessel magnetic bearing (now ");
disp_deg_min(bearing,0);
myputs(")\n");
printf("F. Enter sextant eye height (now %.01lf feet)\n",eye_ht);
printf("G. Enter star/planet list magnitude limit (now %.01lf)\n"
,mag_lim);
myputs("H. List navigation stars' current SHA\n");
myputs("I. List navigation planets' current SHA\n");
myputs("J. List navigation stars' current GHA\n");
myputs("K. List navigation planets' current GHA\n");
myputs("L. List navigation stars' meridian, rise, set times\n");
myputs("M. List navigation planets' meridian, rise, set times\n");
printf("N. Enter object-locator horizon limit angle (now %.01lf deg)\n"
,horiz * RTOD);
myputs("O. Locate navigation stars at current location and time\n");
myputs("P. Locate navigation planets at current location and time\n");
myputs("Q. Compute position by two celestial sightings\n");
myputs("R. Compute position by noon sun sight\n");
printf("S. Set display and entry time zone (now %s)\n",tzlbl);
myputs("T. Exit program\n");
myputs("\nEnter a letter :");
mygets(inbuf,buflen);
c = inbuf[0];
c = toupper(c);
return(c);
}
void docom(int c)
{
int i;
if(!comline)
{
gotoxy(1,24);
cleol();
}
switch (c) {
case 'A':
getdatime(&datime);
now = mdy_sect(datime);
gha_a = getghaa(datime);
break;
case 'B':
getlatlng(&here,1);
break;
case 'C':
if(!comline)
{
cls();
myputs(
" Magnetic deviation is listed on most navigation charts. Enter magnetic\n");
myputs(
" deviation at estimated position as dd.dd (- for easterly):");
}
getsptr = mygets(inbuf,buflen);
mag_dev *= RTOD;
sscanfptr = sscanf(inbuf,"%lf",&mag_dev);
mag_dev *= DTOR;
break;
case 'D':
if(!comline)
myputs("Enter vessel speed (knots):");
getsptr = mygets(inbuf,buflen);
sscanfptr = sscanf(inbuf,"%lf",&speed);
break;
case 'E':
if(!comline)
myputs("Enter vessel magnetic bearing as ddd [mm.mm]:");
getsptr = mygets(inbuf,buflen);
split(inbuf);
i = llscan(0,&bearing);
break;
case 'F':
if(!comline)
myputs("Enter sextant eye height (ft):");
getsptr = mygets(inbuf,buflen);
sscanfptr = sscanf(inbuf,"%lf",&eye_ht);
eye_ht_corr = 2.821615624e-4 * sqrt(eye_ht); /* sextant eye height corr */
break;
case 'G':
if(!comline)
myputs("Enter navigation list magnitude limit:");
getsptr = mygets(inbuf,buflen);
sscanfptr = sscanf(inbuf,"%lf",&mag_lim);
break;
case 'H':
liststars(1,0);
break;
case 'I':
liststars(1,1);
break;
case 'J':
liststars(0,0);
break;
case 'K':
liststars(0,1);
break;
case 'L':
rise_set(0);
break;
case 'M':
rise_set(1);
break;
case 'N':
if(!comline)
myputs("Enter object-locator horizon limit angle:");
getsptr = mygets(inbuf,buflen);
horiz *= RTOD;
sscanfptr = sscanf(inbuf,"%lf",&horiz);
horiz *= DTOR;
break;
case 'O':
findstars(0);
break;
case 'P':
findstars(1);
break;
case 'Q':
starfix();
break;
case 'R':
noonsight();
break;
case 'S':
localt(1);
break;
default:
break;
}
}
int init()
{
int i = 0;
unsigned long qt;
getdat();
while(*(starstrings+i)[0])
{
sscanfptr = sscanf(*(starstrings+i),"%s %lf %lf %lf %lf %lf"
,startable[i].name,&startable[i].magn,&startable[i].sha
,&startable[i].shacor,&startable[i].decl,&startable[i].declcor);
startable[i].semidiam = 0.0;
startable[i].dist = 0.0;
startable[i].sha *= DTOR;
startable[i].shacor *= DTOR;
startable[i].decl *= DTOR;
startable[i].declcor *= DTOR;
i++;
}
for(i = 0;i < 9;i++)
getsptr = strcpy(startable[i+60].name,*(planet_name+i));
startable[69].name[0] = 0;
qt = time(NULL);
now = qt;
datime = sect_mdy(now);
gha_a = getghaa(datime);
eye_ht_corr = 2.821615624e-4 * sqrt(eye_ht); /* sextant eye height corr */
return(i);
}
int ctest(char **c)
{
return((c[0][0] == '-') && (isalpha(c[0][1])));
}
void proc_coml(int argc,char **argv)
{
int com;
comline++;
while(--argc > 0)
{
argv++;
if(ctest(argv))
{
com = toupper(argv[0][1]);
if(argc > 1)
{
inbuf[0] = 0;
do
{
argv++;
argc--;
if(!ctest(argv))
{
strcat(inbuf,*argv);
strcat(inbuf," ");
}
}
while((argc > 0) && (!ctest(argv)));
if(ctest(argv))
{
argv--;
argc++;
}
}
}
docom(com);
}
}
int main(int argc,char **argv)
{
int c = 0;
tzset();
maxstars = init();
gmtdiff_s = (double)timezone;
gmtdiff_h = gmtdiff_s / 3600.0;
lastin[0][0] = 0;
lastin[1][0] = 0;
if(argc > 1)
proc_coml(argc,argv);
else
{
while(c != 'T') /* as in "nearly forever" */
{
c = menu();
docom(c);
}
}
putdat();
return 0;
}