Abstract: Apparatus and method for determining a modulation transfer function of a plurality of radiation detectors (12). The method includes a step of simultaneously illuminating, with a slit illumination source embodied within a phased slit reticle (16b′), a plurality of detector elements that are disposed within a localized area comprised-of rows and columns of a radiation detector array (10). The phased slit reticle has a two dimensional phase characteristic that is a function of a distance between adjacent detector elements. The method includes a further step of determining, from an electrical signal generated by the illuminated detector elements, a line spread function; and a step of determining, by taking a Fourier Transform of the determined line spread function, the modulation transfer function of the detector elements within the localized area.

Abstract: Methods and apparatus that are used in an alkylation reactor system for adding low purity isopentane to alkylation reactor feed to block formation of isopentane, resulting in high incremental isopentane conversion and minimal octane and C5+ yield loss, and low acid consumption from C6+ isoparaffins with superior yields.

Abstract: A process for cooling unreacted hydrocarbon substrate that is recycled to an alkylation reactor and for minimizing the concentration of lower boiling hydrocarbons in such recycle.

Abstract: A system for receiving electromagnetic energy with reduced signal aliasing in the cross-scan direction. The system is adapted to be mounted on a spacecraft or an aircraft for movement over a surface in the cross-scan direction and has a sensor for receiving electromagnetic energy. The invention (10) includes an arrangement for directing energy to the sensor which has an astigmatic blur in the cross-scan direction which is effective to reduce aliasing of a signal transmitted or received by the system in the cross-scan direction of movement. In the illustrative embodiment, the invention (10) includes an array (20) of radiometric detectors. A reflective optical arrangement directs energy from a surface to the detector array. The optical arrangement includes at least one mirror (16) which has a small controlled cylindrical surface perturbation which introduces an astigmatic blur into the received image which reduces aliasing of the signal in the cross-scan direction.