ported slalib.sla_refro, some refactoring

README.md

@@ -41,7 +41,7 @@ disp = dispersion(lat, h)
 disp.setReducedHeight(P, rho)
 
 # Calculation of the atmopheric dipsersion
-atm_dispersion = disp.cassini(n1, z0) * 3.6e6
+atm_dispersion = disp.cassini(n1, n2, z0) * 3.6e6
 print ('The dispersion is %.03f milli arc seconds' %(atm_dispersion))
 ```
 
@@ -60,7 +60,7 @@ The package contains the following files:
 - `/data/1976USSA.txt` 			: Data file of the 1976 US Standard Atmosphere.
 - `ciddorModel.py` 				: Contains the `Observatory()` class to calculate the refractive index of atmospheric air, using the Ciddor (1996) model.
 - `dispersionModels.py` 		: Contains various atmospheric models that can be used to calculate the atmospheric dispersion
-- `examples.py` 				: Contains several quick functions, e.g. to quickly calculate the refractive index.
+- `misc.py` 				: Contains several miscellaneous functions, e.g. to quickly calculate the refractive index.
 - `refractionModels.py`		 		: Contains various atmospheric models that can be used to calculate the atmospheric refraction
 - `refractivityModels.py` 		: Contains various functions from literature to calculate the refractive index. Some examples of works included are Ciddor (1996), Barrell & Sears (1939), SLALIB, Owens (1967) and Edlen (1966).
 
@@ -85,7 +85,7 @@ Basic functionality of other refractivity models is included as well and is disc
 
 ## The atmospheric refraction and atmospheric dispersion models
 
-If the atmospheric refraction is denoted as R(n), then atmospheric dispersion is defined as R(n1) - R(n2). Thus they are very similar in function and also in use.
+If the atmospheric refraction is denoted as R(n), then atmospheric dispersion is defined as R(n1) - R(n2). Thus they are very similar in function and use.
 
 
 The available models in this package:
@@ -96,6 +96,7 @@ The available models in this package:
 - `tan5()` - Oriani's theorem expanded ( Atan(z) + Btan^3(z) + Ctan^5(z)  )
 - `corbard()` - Error function refraction model
 - `matharExponential()` - Barometric exponential model by R. Mathar.
+The package also includes a python native port of the `SLA_REFRO()` FORTRAN routine, ported from pyslalib. See below for more information.
 
 
 Input parameters for the spherical atmosphere models (all but the first):
@@ -190,7 +191,8 @@ Included are
 | Bonsch & Potulski (1998) | `BonschPotulski()` | Function does not include humidity |
 | Birch & Downs (1994) | `BirchDowns()` | Only at standard atmosphere. Function requires wavelength only. |
 | Peck & Reeder (1972) | `PeckReeder()` | Only at standard atmosphere. Function requires wavelength only. |
-| Hohenkerk & Sinclair (1985) | `slalib()` | Only at standard atmosphere. Function requires wavelength only. |
+| Hohenkerk & Sinclair (1985) | `HohenkerkAndSinclair()` | Based on Barrell & Sears equation. Generally, gives slightly larger values.|
+| Hohenkerk & Sinclair (1985) | `slalib()` | Uses pySLALIB to retrieve the refractive index at standard atmospheric conditions.|
 
 The last function extracts the refractive index from the `pyslalib.sla_refro()` function and thus requires [pyslalib](https://pypi.org/project/pySLALIB/). This is an optional dependency for the setup of AstroAtmosphere.
 
@@ -210,3 +212,7 @@ rq = quick_refraction(l1, zenith_obs, conditions='STANDARD')
 # Quick dispersion
 dq = quick_dispersion(l1, l2, zenith_obs, conditions='STANDARD')
 ```
+
+## Other
+
+This package also contains a python native port of the `SLA_REFRO()` routine of the pyslalib package, which was originally written in FORTRAN by P.T. Wallace. It can be called directly using `sla_refro()`. When using the same units as the other refraction functions, you might prefer using `slalib_refraction()` or `slalib_dispersion()`.