text: /*  Space oblique for LANDSAT */
  #ifndef lint
  static const char SCCSID[]="@(#)PJ_lsat.c	4.4	93/06/12	GIE	REL";
  #endif
  /* based upon Snyder and Linck, USGS-NMD */
  #define PROJ_PARMS__ \
      double a2, a4, b, c1, c3; \
      double q, t, u, w, p22, sa, ca, xj, rlm, rlm2;
  #define PJ_LIB__
  #include	<projects.h>
  #define TOL 1e-7
  #define PI_HALFPI 4.71238898038468985766
  #define TWOPI_HALFPI 7.85398163397448309610
  	static void
  seraz0(double lam, double mult, PJ *P) {
      double sdsq, h, s, fc, sd, sq, d__1;
  
      lam *= DEG_TO_RAD;
      sd = sin(lam);
      sdsq = sd * sd;
      s = P->p22 * P->sa * cos(lam) * sqrt((1. + P->t * sdsq) / ((
  	    1. + P->w * sdsq) * (1. + P->q * sdsq)));
      d__1 = 1. + P->q * sdsq;
      h = sqrt((1. + P->q * sdsq) / (1. + P->w * sdsq)) * ((1. + 
  	    P->w * sdsq) / (d__1 * d__1) - P->p22 * P->ca);
      sq = sqrt(P->xj * P->xj + s * s);
      P->b += fc = mult * (h * P->xj - s * s) / sq;
      P->a2 += fc * cos(lam + lam);
      P->a4 += fc * cos(lam * 4.);
      fc = mult * s * (h + P->xj) / sq;
      P->c1 += fc * cos(lam);
      P->c3 += fc * cos(lam * 3.);
  }
  FORWARD(e_forward); /* ellipsoid */
      int l, nn;
      double lamt, xlam, sdsq, c, d, s, lamdp, phidp, lampp, tanph,
  		lamtp, cl, sd, sp, fac, sav, tanphi;
  
  	if (lp.phi > HALFPI)
  	    lp.phi = HALFPI;
  	else if (lp.phi < -HALFPI)
  	    lp.phi = -HALFPI;
  	lampp = lp.phi >= 0. ? HALFPI : PI_HALFPI;
  	tanphi = tan(lp.phi);
  	for (nn = 0;;) {
  		sav = lampp;
  		lamtp = lp.lam + P->p22 * lampp;
  		cl = cos(lamtp);
  		if (fabs(cl) < TOL)
  		    lamtp -= TOL;
  		fac = lampp - sin(lampp) * (cl < 0. ? -HALFPI : HALFPI);
  		for (l = 50; l; --l) {
  			lamt = lp.lam + P->p22 * sav;
  			if (fabs(c = cos(lamt)) < TOL)
  			    lamt -= TOL;
  			xlam = (P->one_es * tanphi * P->sa + sin(lamt) * P->ca) / c;
  			lamdp = atan(xlam) + fac;
  			if (fabs(fabs(sav) - fabs(lamdp)) < TOL)
  			    break;
  			sav = lamdp;
  		}
  		if (!l || ++nn >= 3 || (lamdp > P->rlm && lamdp < P->rlm2))
  			break;
  		if (lamdp <= P->rlm)
  		    lampp = TWOPI_HALFPI;
  		else if (lamdp >= P->rlm2)
  		    lampp = HALFPI;
  	}
  	if (l) {
  		sp = sin(lp.phi);
  		phidp = aasin((P->one_es * P->ca * sp - P->sa * cos(lp.phi) * 
  			sin(lamt)) / sqrt(1. - P->es * sp * sp));
  		tanph = log(tan(FORTPI + .5 * phidp));
  		sd = sin(lamdp);
  		sdsq = sd * sd;
  		s = P->p22 * P->sa * cos(lamdp) * sqrt((1. + P->t * sdsq)
  			 / ((1. + P->w * sdsq) * (1. + P->q * sdsq)));
  		d = sqrt(P->xj * P->xj + s * s);
  		xy.x = P->b * lamdp + P->a2 * sin(2. * lamdp) + P->a4 *
  			sin(lamdp * 4.) - tanph * s / d;
  		xy.y = P->c1 * sd + P->c3 * sin(lamdp * 3.) + tanph * P->xj / d;
  	} else
  		xy.x = xy.y = HUGE_VAL;
  	return xy;
  }
  INVERSE(e_inverse); /* ellipsoid */
      int nn;
      double lamt, sdsq, s, lamdp, phidp, sppsq, dd, sd, sl, fac, scl, sav, spp;
  
  	lamdp = xy.x / P->b;
  	nn = 50;
  	do {
  		sav = lamdp;
  		sd = sin(lamdp);
  		sdsq = sd * sd;
  		s = P->p22 * P->sa * cos(lamdp) * sqrt((1. + P->t * sdsq)
  			 / ((1. + P->w * sdsq) * (1. + P->q * sdsq)));
  		lamdp = xy.x + xy.y * s / P->xj - P->a2 * sin(
  			2. * lamdp) - P->a4 * sin(lamdp * 4.) - s / P->xj * (
  			P->c1 * sin(lamdp) + P->c3 * sin(lamdp * 3.));
  		lamdp /= P->b;
  	} while (fabs(lamdp - sav) >= TOL && --nn);
  	sl = sin(lamdp);
  	fac = exp(sqrt(1. + s * s / P->xj / P->xj) * (xy.y - 
  		P->c1 * sl - P->c3 * sin(lamdp * 3.)));
  	phidp = 2. * (atan(fac) - FORTPI);
  	dd = sl * sl;
  	if (fabs(cos(lamdp)) < TOL)
  	    lamdp -= TOL;
  	spp = sin(phidp);
  	sppsq = spp * spp;
  	lamt = atan(((1. - sppsq * P->rone_es) * tan(lamdp) * 
  		P->ca - spp * P->sa * sqrt((1. + P->q * dd) * (
  		1. - sppsq) - sppsq * P->u) / cos(lamdp)) / (1. - sppsq 
  		* (1. + P->u)));
  	sl = lamt >= 0. ? 1. : -1.;
  	scl = cos(lamdp) >= 0. ? 1. : -1;
  	lamt -= HALFPI * (1. - scl) * sl;
  	lp.lam = lamt - P->p22 * lamdp;
  	if (fabs(P->sa) < TOL)
  	    lp.phi = aasin(spp / sqrt(P->one_es * P->one_es + P->es * sppsq));
  	else
  		lp.phi = atan((tan(lamdp) * cos(lamt) - P->ca * sin(lamt)) /
  			(P->one_es * P->sa));
  	return lp;
  }
  FREEUP; if (P) pj_dalloc(P); }
  ENTRY0(pj_lsat)
      int land, path;
      double lam, alf, esc, ess;
  
  	land = pj_param(P->params, "ilsat").i;
  	if (land <= 0 || land > 5) E_ERROR(-28);
  	path = pj_param(P->params, "ipath").i;
  	if (path <= 0 || path > (land <= 3 ? 251 : 233)) E_ERROR(-29);
  	if (land <= 3) {
  		P->lam0 = DEG_TO_RAD * 128.87 - TWOPI / 251. * path;
  	    P->p22 = 103.2669323;
  	    alf = DEG_TO_RAD * 99.092;
  	} else {
  		P->lam0 = DEG_TO_RAD * 129.3 - TWOPI / 233. * path;
  	    P->p22 = 98.8841202;
  	    alf = DEG_TO_RAD * 98.2;
  	}
  	P->p22 /= 1440.;
  	P->sa = sin(alf);
  	P->ca = cos(alf);
  	if (fabs(P->ca) < 1e-9)
  	    P->ca = 1e-9;
  	esc = P->es * P->ca * P->ca;
  	ess = P->es * P->sa * P->sa;
  	P->w = (1. - esc) * P->rone_es;
  	P->w = P->w * P->w - 1.;
  	P->q = ess * P->rone_es;
  	P->t = ess * (2. - P->es) * P->rone_es * P->rone_es;
  	P->u = esc * P->rone_es;
  	P->xj = P->one_es * P->one_es * P->one_es;
  	P->rlm = PI * (1. / 248. + .5161290322580645);
  	P->rlm2 = P->rlm + TWOPI;
      P->a2 = P->a4 = P->b = P->c1 = P->c3 = 0.;
  	seraz0(0., 1., P);
  	for (lam = 9.; lam <= 81.0001; lam += 18.)
  	    seraz0(lam, 4., P);
  	for (lam = 18; lam <= 72.0001; lam += 18.)
  	    seraz0(lam, 2., P);
  	seraz0(90., 1., P);
  	P->a2 /= 30.;
  	P->a4 /= 60.;
  	P->b /= 30.;
  	P->c1 /= 15.;
  	P->c3 /= 45.;
  	P->inv = e_inverse; P->fwd = e_forward;
  ENDENTRY(P)
  