diff --git a/docs/ionosphere.md b/docs/ionosphere.md index 3343e63..07f4b0d 100644 --- a/docs/ionosphere.md +++ b/docs/ionosphere.md @@ -8,7 +8,7 @@ model ionosphere is currently hard coded to zero inside TTCal. The index of refraction of a cold, collisionless, and unmagnetized plasma is \[ - n = \sqrt{1 - \frac{\omega_p}{\omega}}, + n = \sqrt{1 - \frac{\omega_p^2}{\omega^2}}, \] where $\omega_p$ is the diff --git a/docs/sourcemodel.md b/docs/sourcemodel.md index 32a60ce..94763e8 100644 --- a/docs/sourcemodel.md +++ b/docs/sourcemodel.md @@ -70,15 +70,61 @@ the values contained in `index`. ## Gaussian Sources -Support for Gaussian sources is coming! +Gaussians sources can be added to the sky model by defining `major-fwhm`, `minor-fwhm`, +and `position-angle`. + +* `major-fwhm` is the full width at half maximum (FWHM) of the major axis in arcseconds +* `minor-fwhm` is the FWHM of the minor axis in arcseconds +* `position-angle` is the angle the major axis makes with J2000 north where a positive angle is east of north + +Note that the Stokes parameters `I`, `Q`, `U`, and `V` now give the integrated flux +over the entire source. An example Gaussian source is given below: + +``` + ... + { + "ref": "Michael's imagination", + "name": "A Gaussian source", + "ra": "12h34m56.78s", + "dec": "+12d34m56.78s", + "I": 123.45, + "freq": 70e6, + "index": [-0.770], + "major-fwhm": 200, + "minor-fwhm": 100, + "position-angle": -70 + } + ... +``` + +## Multi-Component Sources + +When peeling sources with TTCal each source receives its own peeling solution. This is not +always the desired behavior. For example if you are trying to peel Cyg A you might want to +use two sources to describe the two radio lobes, but both sources should be peeled with +the same solution. Multi-component sources allow you to define sources that are composed +of any number of the other source types. For example: + +``` + ... + { + "name": "Cyg A", + "components": [ + { + "name": "east lobe", + ... + }, + { + "name": "west lobe", + ... + } + ] + } + ... +``` ## Near-Field Sources Experimental support for near-field sources is currently available in the latest version of TTCal. Because this is an experimental feature it is not yet very easy to use. -## Diffuse Emission - -Diffuse emission is currently not supported within TTCal. Eventual support is on the -horizon. -