NIRISSForwardRowGrismDispersion
- class stdatamodels.jwst.transforms.NIRISSForwardRowGrismDispersion(orders, lmodels=None, xmodels=None, ymodels=None, theta=0.0, sampling=10)
Bases:
_WFSSForwardGrismDispersionCalculate the wavelengths of vertically dispersed NIRISS grism data.
The dispersion polynomial is relative to the input x,y pixels in the direct image for a given wavelength.
Initialize the model.
- Parameters:
- orderslist[int]
List of spectral orders corresponding to the dispersion models given by the lmodels, xmodels, and ymodels parameters.
- lmodelslist[
astropy.modeling.core.Model] The forward dispersion polynomial models, one per order, such that wavelength = lmodel(t) computes the trace parameter from the wavelength.
- xmodelslist[list[
astropy.modeling.polynomial.Polynomial2D]] The models encoding the x-position of the spectral trace. Because the shape of the trace depends on the direct-image x0, y0 position, this takes the form dx = C0(x0, y0) + C1(x0, y0) * t + C2(x0, y0) * t^2. The inner list corresponds to the 2-D polynomials (C0, C1, C2). The outer list corresponds to the different spectral orders.
- ymodelslist[list[
astropy.modeling.polynomial.Polynomial2D]] The models encoding the y-position of the spectral trace. Because the shape of the trace depends on the direct-image x0, y0 position, this takes the form dy = C0(x0, y0) + C1(x0, y0) * t + C2(x0, y0) * t^2. The inner list corresponds to the 2-D polynomials (C0, C1, C2). The outer list corresponds to the different spectral orders.
- thetafloat
Angle [deg] - defines the NIRISS filter wheel position
- samplingint, optional
Number of sampling points in t to use; these will be linearly interpolated.