These help pages were designed at the

Clarendon Laboratory, Department of Physics, Oxford University, U.K.

by A. Tennant and D. McMorrow.

The rescal option on the "Rescal: Parameters" window menu bar executes the calculation of the resolution ellipsoid. A figure is generated which has: 

a pull-down print menu as well as output showing method used spectrometer parameters lattice parameters Bragg widths: Qx-radial width, Qy-transverese width, Qz-vertical width, V-vanadium width, and DEE-energy width all expressed as FWHM and units of Ang-1 or meV. resolution volumes: R0-total volume, Vi-volume before sample, Vf-after-sample volume. dispersion surface and scan parameters phonon width: full width half maximum of a scan DQ through the dispersion surface GQ in units of Ang-1, meV or a mixture of both. three projections of the resolution ellipsoid onto the Qx-Qy, Qx-Energy, and Qy-Energy planes where Qx is the radial direction i.e. along the direction of momentum transfer Q and Qy is the transverse direction i.e. perpendicular to Q in the scattering plane. 

A screen shot of the output figure is given below.