Merge branch 'improve_model' into 'jeroen'

Improve model

See merge request !14

common/utils/dt_model.c

@@ -63,16 +63,16 @@ struct dt_model_params *params = &dt_model_default;
 double dt_model_azimuth_delta(double az, double el)
 {
 	double delta_az;
-	double c1_div_cos_el = params->c1 / cos(el);
-	
+	double c1_div_cos_el = params->c1 / cos(2*M_PI*el/360.);
+
 	if (isnan(c1_div_cos_el))
 		c1_div_cos_el = 0.0;
 	
 	delta_az = 
 	    params->a0 
-	    + params->c1 / cos(el) 
-	    - params->c2 * tan(el) 
-	    - params->za * sin(az - params->aa) * tan(el);
+	    + params->c1 / cos(2*M_PI*el/360.)
+	    - params->c2 * tan(2*M_PI*el/360.)
+	    - params->za * sin(az - params->aa) * tan(2*M_PI*el/360.);
 
 	return delta_az;
 }
@@ -80,7 +80,8 @@ double dt_model_azimuth_delta(double az, double el)
 double dt_model_azimuth_delta_rev(double az, double el)
 {
 	/* No reverse model available, (ab)use the forward model */
-	return -dt_model_azimuth_delta(az, el);
+	return -dt_model_azimuth_delta(az - params->a0 - params->c1/cos(2*M_PI*(el-params->e0)/360.),
+                                       el - params->e0);
 }
 
 double dt_model_elevation_delta(double az, double el)
@@ -89,16 +90,17 @@ double dt_model_elevation_delta(double az, double el)
 
 	delta_el =
 	     params->e0 
-	     + params->b * cos(el) 
-	     - params->za * cos(az - params->aa);
-	
+	     + params->b * cos(2*M_PI*el/360.)
+	     - params->za * cos(2*M_PI*(az - params->aa)/360.);
+
 	return delta_el;
 }
 
 double dt_model_elevation_delta_rev(double az, double el)
 {
 	/* No reverse model available, (ab)use the forward model */
-	return -dt_model_elevation_delta(az, el);
+	return -dt_model_elevation_delta(az - params->a0 - params->c1/cos(2*M_PI*(el-params->e0)/360.),
+                                         el - params->e0);
 }
 
 int dt_model_init(void)