Fix ERA GST constant mixup, add more tests

README-headless.md

@@ -248,7 +248,7 @@ adjustment to convert from J2000 to ICRS coordinates.
  transform_cat(CHANGE_EPOCH, NOVAS_B1950, &source, NOVAS_J2000, "FK5", &source);
   
  // Then convert J2000 coordinates to ICRS (also in place). Here the dates don't matter...
- transform_cat(CHANGE_J2000_TO_ICRS, 0.0, &source, 0.0, "ICR", &source);
+ transform_cat(CHANGE_J2000_TO_ICRS, 0.0, &source, 0.0, "ICRS", &source);
 ```
 
 (Naturally, you can skip the transformation steps above if you have defined your source in ICRS coordinates from the 
@@ -326,15 +326,15 @@ at the specified observing location (without refraction correction):
  double zd, az;
 
  // Convert CIRS to horizontal using the pole offsets.
- cirs_to_hor(jd_tt - ut1_to_tt, ut1_to_tt, NOVAS_FULL_ACCURACY, dx, dy, &obs.on_surf, pos.ra, pos.dec, 
-             &zd, &az);
+ cirs_to_hor(jd_tt - ut1_to_tt, ut1_to_tt, NOVAS_FULL_ACCURACY, dx, dy, &obs.on_surf, 
+             pos.ra, pos.dec, &zd, &az);
 ``` 
 
 In the example above we first calculated the apparent coordinates in the Celestial Intermediate Reference System 
 (CIRS). Then we used `cirs_to_hor()` function then convert first it to the Earth-fixed International Terrestrial 
 Reference system (ITRS) using the small (arcsec-level) measured variation of the pole (dx, dy) provided explicitly 
 since `cirs_to_hor()` does not use the values previously set via `cel_pole()`. Finally, `cirs_to_hor()` converts the 
-ITRScoordinates to the horizontal system at the observer location.
+ITRS coordinates to the horizontal system at the observer location.
 
 You can additionally apply an optical refraction correction for the astrometric (unrefracted) zenith angle, if you 
 want, e.g.:
@@ -462,7 +462,7 @@ on how they are appropriate for the old and new methodologies respectively.
    invalid (unless the NOVAS C API already defined a different return value for specific cases. If so, the NOVAS C
    error code is returned for compatibility).
 
- - Many SuperNOVAS functions allow NULL arguments, both for optional input values as well as outputs that are not 
+ - Many SuperNOVAS functions allow `NULL` arguments, both for optional input values as well as outputs that are not 
    required. See the [API Documentation](https://smithsonian.github.io/SuperNOVAS.home/apidoc/html/) for specifics).
    This eliminates the need to declare dummy variables in your application code.
 
@@ -475,10 +475,9 @@ on how they are appropriate for the old and new methodologies respectively.
    data content being pointed at. This supports better programming practices that generally aim to avoid unintended 
    data modifications.
 
- - New `cirs_to_hor()` function similar to the existing `equ2hor()`. Whereas the latter converts from TOD to
-   to local horizontal (old methodology), the new function does the same from CIRS (new IAU standard methodology).
-   As such it can be used after `place()` is called with `NOVAS_CIRS` as the coordinate system. 
-
+ - Source names and catalog names can both be up to 64 bytes (including termination), up from 51 and 4 respectively
+   NOVAS C, while keeping `struct` layouts the same thanks to alignment.
+
  - Runtime configurability:
 
    * The planet position calculator function used by `ephemeris` can be set at runtime via `set_planet_calc()`, and
@@ -495,7 +494,20 @@ on how they are appropriate for the old and new methodologies respectively.
      approximation via `nutation_set_lp_calc()`. For example, the user may want to use the `iau2000b()` model instead 
      or some custom algorithm instead.
 
- - Added several new convenience functions to wrap `place()` for simpler specific use: `place_star()`, `place_icrs()`, 
+ - New intutitive XYZ coordinate coversion functions:
+   * for GCRS - CIRS - ITRS (IAU 2000 standard): `gcrs_to_cirs()`, `cirs_to_itrs()`, and `itrs_to_cirs()`, 
+     `cirs_to_gcrs()`.
+   * for J2000 - TOD - ITRS (old methodology): `j2000_to_tod()`, `tod_to_itrs()`, and `itrs_to_tod()`, 
+     `tod_to_j2000()`.
+
+ - New `cirs_to_hor()` function similar to the existing `equ2hor()`. Whereas the latter converts from TOD to
+   to local horizontal (old methodology), the new function does the same from CIRS (new IAU standard methodology).
+   As such it can be used after `place()` is called with `NOVAS_CIRS` as the coordinate system. 
+
+ - New `refract_astro()` function that complements the existing `refract()` but takes an unrefracted zenith angle
+   as its argument.
+
+ - New convenience functions to wrap `place()` for simpler specific use: `place_star()`, `place_icrs()`, 
    `place_gcrs()`, `place_cirs()`, `place_tod()`.
 
  - New time conversion utilities `tt2tdb()` and `get_ut1_to_tt()` make it simpler to convert between UT1, TT, and TDB

README.md

@@ -260,7 +260,7 @@ adjustment to convert from J2000 to ICRS coordinates.
  transform_cat(CHANGE_EPOCH, NOVAS_B1950, &source, NOVAS_J2000, "FK5", &source);
   
  // Then convert J2000 coordinates to ICRS (also in place). Here the dates don't matter...
- transform_cat(CHANGE_J2000_TO_ICRS, 0.0, &source, 0.0, "ICR", &source);
+ transform_cat(CHANGE_J2000_TO_ICRS, 0.0, &source, 0.0, "ICRS", &source);
 ```
 
 (Naturally, you can skip the transformation steps above if you have defined your source in ICRS coordinates from the 
@@ -338,15 +338,15 @@ at the specified observing location (without refraction correction):
  double zd, az;
 
  // Convert CIRS to horizontal using the pole offsets.
- cirs_to_hor(jd_tt - ut1_to_tt, ut1_to_tt, NOVAS_FULL_ACCURACY, dx, dy, &obs.on_surf, pos.ra, pos.dec, 
-             &zd, &az);
+ cirs_to_hor(jd_tt - ut1_to_tt, ut1_to_tt, NOVAS_FULL_ACCURACY, dx, dy, &obs.on_surf, 
+             pos.ra, pos.dec, &zd, &az);
 ``` 
 
 In the example above we first calculated the apparent coordinates in the Celestial Intermediate Reference System 
 (CIRS). Then we used `cirs_to_hor()` function then convert first it to the Earth-fixed International Terrestrial 
 Reference system (ITRS) using the small (arcsec-level) measured variation of the pole (dx, dy) provided explicitly 
 since `cirs_to_hor()` does not use the values previously set via `cel_pole()`. Finally, `cirs_to_hor()` converts the 
-ITRScoordinates to the horizontal system at the observer location.
+ITRS coordinates to the horizontal system at the observer location.
 
 You can additionally apply an optical refraction correction for the astrometric (unrefracted) zenith angle, if you 
 want, e.g.:
@@ -474,7 +474,7 @@ on how they are appropriate for the old and new methodologies respectively.
    invalid (unless the NOVAS C API already defined a different return value for specific cases. If so, the NOVAS C
    error code is returned for compatibility).
 
- - Many SuperNOVAS functions allow NULL arguments, both for optional input values as well as outputs that are not 
+ - Many SuperNOVAS functions allow `NULL` arguments, both for optional input values as well as outputs that are not 
    required. See the [API Documentation](https://smithsonian.github.io/SuperNOVAS.home/apidoc/html/) for specifics).
    This eliminates the need to declare dummy variables in your application code.
 
@@ -487,10 +487,9 @@ on how they are appropriate for the old and new methodologies respectively.
    data content being pointed at. This supports better programming practices that generally aim to avoid unintended 
    data modifications.
 
- - New `cirs_to_hor()` function similar to the existing `equ2hor()`. Whereas the latter converts from TOD to
-   to local horizontal (old methodology), the new function does the same from CIRS (new IAU standard methodology).
-   As such it can be used after `place()` is called with `NOVAS_CIRS` as the coordinate system. 
-
+ - Source names and catalog names can both be up to 64 bytes (including termination), up from 51 and 4 respectively
+   NOVAS C, while keeping `struct` layouts the same thanks to alignment.
+
  - Runtime configurability:
 
    * The planet position calculator function used by `ephemeris` can be set at runtime via `set_planet_calc()`, and
@@ -507,7 +506,20 @@ on how they are appropriate for the old and new methodologies respectively.
      approximation via `nutation_set_lp_calc()`. For example, the user may want to use the `iau2000b()` model instead 
      or some custom algorithm instead.
 
- - Added several new convenience functions to wrap `place()` for simpler specific use: `place_star()`, `place_icrs()`, 
+ - New intutitive XYZ coordinate coversion functions:
+   * for GCRS - CIRS - ITRS (IAU 2000 standard): `gcrs_to_cirs()`, `cirs_to_itrs()`, and `itrs_to_cirs()`, 
+     `cirs_to_gcrs()`.
+   * for J2000 - TOD - ITRS (old methodology): `j2000_to_tod()`, `tod_to_itrs()`, and `itrs_to_tod()`, 
+     `tod_to_j2000()`.
+
+ - New `cirs_to_hor()` function similar to the existing `equ2hor()`. Whereas the latter converts from TOD to
+   to local horizontal (old methodology), the new function does the same from CIRS (new IAU standard methodology).
+   As such it can be used after `place()` is called with `NOVAS_CIRS` as the coordinate system. 
+
+ - New `refract_astro()` function that complements the existing `refract()` but takes an unrefracted zenith angle
+   as its argument.
+
+ - New convenience functions to wrap `place()` for simpler specific use: `place_star()`, `place_icrs()`, 
    `place_gcrs()`, `place_cirs()`, `place_tod()`.
 
  - New time conversion utilities `tt2tdb()` and `get_ut1_to_tt()` make it simpler to convert between UT1, TT, and TDB

include/novas.h

@@ -258,16 +258,24 @@ enum novas_accuracy {
  */
 enum novas_refraction_model {
   NOVAS_NO_ATMOSPHERE = 0,            ///< Do not apply atmospheric refraction correction
-  NOVAS_STANDARD_ATMOSPHERE, ///< Uses a standard atmospheric model, ignoring all weather values defined for the specific observing location
+  NOVAS_STANDARD_ATMOSPHERE,          ///< Uses a standard atmospheric model, ignoring all weather values defined for the specific observing location
   NOVAS_WEATHER_AT_LOCATION           ///< Uses the weather parameters that are specified together with the observing location.
 };
 
 /**
  * Constants that determine the type of rotation measure to use.
  */
 enum novas_earth_rotation_measure {
-  EROT_GST = 0,                   ///< Use GST as the rotation measure, relative to the true equinox (before IAU 20006 standard)
-  EROT_ERA                        ///< Use Earth Rotation Angle (ERA) as the rotation measure, relative to the CIO (new IAU 2006 standard)
+  EROT_ERA = 0,              ///< Use Earth Rotation Angle (ERA) as the rotation measure, relative to the CIO (new IAU 2006 standard)
+  EROT_GST                   ///< Use GST as the rotation measure, relative to the true equinox (before IAU 20006 standard)
+};
+
+/**
+ * Constants for ter2cel() and cel2ter()
+ */
+enum novas_celestial_class {
+  CELESTIAL_GCRS = 0,        ///< Celestial coordinates are in GCRS
+  CELESTIAL_APPARENT         ///< Celestial coordinates are apparent values (CIRS or TOD)
 };
 
 /**
@@ -604,10 +612,10 @@ short sidereal_time(double jd_high, double jd_low, double ut1_to_tt, enum novas_
 double era(double jd_high, double jd_low);
 
 short ter2cel(double jd_ut1_high, double jd_ut1_low, double ut1_to_tt, enum novas_earth_rotation_measure method, enum novas_accuracy accuracy,
-        enum novas_reference_system option, double xp, double yp, const double *vec1, double *vec2);
+        enum novas_celestial_class class, double xp, double yp, const double *vec1, double *vec2);
 
 short cel2ter(double jd_ut1_high, double jd_ut1_low, double ut1_to_tt, enum novas_earth_rotation_measure method, enum novas_accuracy accuracy,
-        enum novas_reference_system option, double xp, double yp, const double *vec1, double *vec2);
+        enum novas_celestial_class class, double xp, double yp, const double *vec1, double *vec2);
 
 int spin(double angle, const double *pos1, double *pos2);
 
@@ -733,9 +741,6 @@ int place_cirs(double jd_tt, const object *source, enum novas_accuracy accuracy,
 
 double refract_astro(const on_surface *location, enum novas_refraction_model ref_option, double zd_calc);
 
-int cirs_to_hor(double jd_ut1, double ut1_to_tt, enum novas_accuracy accuracy, double xp, double yp, const on_surface *location, double ra,
-        double dec, double *zd, double *az);
-
 int light_time2(double jd_tdb, const object *ss_object, const double *pos_obs, double tlight0, enum novas_accuracy accuracy, double *pos,
         double *vel, double *tlight);
 
@@ -769,6 +774,9 @@ int itrs_to_tod(double jd_ut1_high, double jd_ut1_low, double ut1_to_tt, enum no
 int tod_to_j2000(double jd_tt, enum novas_accuracy accuracy, const double *in, double *out);
 
 
+int cirs_to_hor(double jd_ut1, double ut1_to_tt, enum novas_accuracy accuracy, double xp, double yp, const on_surface *location, double ra,
+        double dec, double *zd, double *az);
+
 #include "solarsystem.h"
 
 #endif /* _NOVAS_ */