.. _bolometer_geometry_voxels: Calculating a Geometry Matrix using the Voxel Framework ======================================================= In this demonstration, we calculate the geometry matrix for a slightly more complicated bolometer system, consisting of 3 cameras each of which have 16 foils looking through a single aperture. For simplicity we discretise the measurement space into toroidally symmetric voxels of identical rectangular cross section, although it is possible to have an arbitrary cross section in the voxel framework. In addition to the geometry matrix, a regularisation operator is generated. This is needed for regularised tomographic inversions, as shown in the :ref:`Inversion with Voxels ` demo. We use a simple Laplacian operator as the regularisation operator, which corresponds to isotropic smoothing. .. literalinclude:: ../../../../demos/observers/bolometry/geometry_matrix_with_voxels.py .. figure:: bolometer_inversion_lines_of_sight.svg :align: center **Caption** The lines of sight of the 48 foils in 3 bolometer cameras, used to generate the sensitivity matrix. .. figure:: bolometer_voxel_sensitivities.png :align: center **Caption** The result of summing the sensitivty of all foils, for each voxel in the voxel collection.