Abstract: An improved scratch card instant lottery ticket includes micro-encapsulated chemical reactants which, when released, irreversibly form one of a visual color change or a fluorescence signature at a location of the card. Both the visual color change and fluorescence signature indicate that the location has been played. Scratch cards are also marked to indicate that they have been read. Cards are marked by either automatically activating chemical reactants to form a visual color and a fluorescence signature, heating a thermofluorescent material to alter a fluorescence signature, or applying a heat-responsive material to the scratch card in such that when the identification code is read, an altered material is detected. Also taught are a method and apparatus for evaluating the scratch card to determine which locations on the card have been played.

Abstract: A method is disclosed for operating a first satellite communications system of a type that operates co-frequency with at least one second transmission system, such as a second satellite communications system. The method includes steps, executed during the operation of the first satellite communications system, of measuring at a plurality of locations within a coverage area of the first system an amount of interference resulting at least in part from the at least one second transmission system, the amount of interference being measured over a band of frequencies allocated to the first system; (b) transmitting an indication of the measured interference from each location to a central site; and (c) in accordance with the transmitted indications, assigning at least one user terminal to a sub-band of frequencies within the band of frequencies so as to reduce an amount of interference experienced by the user terminal.