Abstract: A terrain-referenced navigation system for an aircraft comprises: a stored digital terrain map; a position calculation unit arranged to calculate aircraft position relative to the stored digital terrain map to determine a terrain-referenced aircraft position; a fall line calculation unit arranged to calculate a fall line for a projectile starting from the terrain-referenced aircraft position as a launch point; and an impact point calculation unit arranged to directly compare the fall line with the digital terrain map, by incrementally comparing a height of the projectile along the fall line with a height of the terrain according to the stored digital terrain map in order to find an expected impact point on the terrain.

Abstract: A terrain-referenced navigation system for an aircraft comprises: a stored digital terrain map; a position calculation unit arranged to calculate aircraft position relative to the stored digital terrain map to determine a terrain-referenced aircraft position; a fall line calculation unit arranged to calculate a fall line for a projectile starting from the terrain-referenced aircraft position as a launch point; and an impact point calculation unit arranged to directly compare the fall line with the digital terrain map, by incrementally comparing a height of the projectile along the fall line with a height of the terrain according to the stored digital terrain map in order to find an expected impact point on the terrain.

Abstract: A navigation system comprising: an inertial navigation system, INS, arranged to provide an INS position estimate and an INS attitude estimate; a terrain based navigation system arranged to provide a terrain based position estimate; a star tracker system arranged to provide a star tracker position and/or attitude estimate; a navigation filter arranged to receive the INS position estimate, the terrain based position estimate, the INS attitude estimate and the star tracker position and/or attitude estimate; the navigation filter arranged to determine an INS error state based at least on the INS position estimate, the terrain based position estimate, the INS attitude estimate and the star tracker position and/or attitude estimate; and the navigation system arranged to output a navigation solution comprising the INS position estimate corrected by the INS error state and the INS attitude estimate corrected by the INS error state.

Abstract: The present invention provides a pipeline pig (10) comprising an elongate body (12) and annular front and rear supports (26,30) projecting radially from the body (12). Each support (26,30) has an upstream side and a downstream side, with the front support (26) including at least one first fluid passage (18) permitting fluid flow from the upstream side to the downstream side. and the rear support (30) including at least one second fluid passage (22) permitting fluid flow from the upstream side to the downstream side. The pig further comprises a launch valve (50) adapted to move from an open position to a closed position to close the at least one first fluid passage (18), and a control means adapted to control the closing of the launch valve (50). A launch trap for launching pigs into a pipeline is also provided.

Abstract: The present invention provides a pipeline pig (10) comprising an elongate body (12) and annular front and rear supports (26,30) projecting radially from the body (12). Each support (26,30) has an upstream side and a downstream side, with the front support (26) including at least one first fluid passage (18) permitting fluid flow from the upstream side to the downstream side, and the rear support (30) including at least one second fluid passage (22) permitting fluid flow from the upstream side to the downstream side. The pig further comprises a launch valve (50) adapted to move from an open position to a closed position to close the at least one first fluid passage (18), and a control means adapted to control the closing of the launch valve (50). A launch trap for launching pigs into a pipeline is also provided.

Abstract: A terrain mapping apparatus (1) carried by an aircraft is arranged to receive height data from a terrain elevation data array memory (7), to determine the correlation between elements of the terrain elevation data array memory (7) and detected height data stored in elements of a laser obstacle detector co-ordinate frame memory (4). The height data of the laser obstacle detector co-ordinate frame memory being provided by a laser obstacle detector (3) monitoring terrain overflown by the aircraft. Updated height data, determined by a mapping processor 5 for each element of the terrain elevation data array memory (7) is provided from height data associated with a predetermined number, typically four, surrounding elements of the laser obstacle detector co-ordinate frame memory (4) and updated height data is then stored in a digital elevation array memory (8).

Abstract: This invention relates generally to a process for the production of butyraldehyde by the catalytic hydroformylation of:A. gaseous propylene;B. hydrogen;C. carbon monoxide, the hydrogen and carbon monoxide being present in a molar ratio within the range 1:15 and 2:1; andD. a catalytically effective quantity of a hydrido carbonyl complex of rhodium which includes two phosphorus-containing stabilizing donor ligands selected from the group consisting of triphenyl phosphine and triphenylphosphite.

Abstract: The invention described in the specification concerns a process for the homogeneous liquid phase hydrogenation of an olefinically or acetylenically unsaturated organic compound to produce a compound having a lower degree of unsaturation by contact of the said organic compound with molecular hydrogen in the presence of a catalyst solution containing a catalytically effective amount of a cation selected from the group consisting of:M.sup.n.sup.+.sub.2 ; M.sub.2 (OCOR).sup.n.sup.+.sub.4.sup.-n ; M.sub.2 (OCSR).sup.n.sup.+.sub.4.sup.-n and M.sub.2 (SCSR).sup.n.sup.+.sub.4.sup.-nThe said solution being prepared by the addition of strong acid to a solution of a compound selected from the group consisting of:M.sub.2 (OCOR).sub.4 ; M.sub.2 (OCOR).sub.4 L; M.sub.2 (OCOR).sub.4 L.sub.2 ; M.sub.2 (OCSR).sub.4 ; M.sub.2 (OCSR).sub.4 L;M.sub.2 (OCSR).sub.4 L.sub.2 ; M.sub.2 (SCSR).sub.4 ; M.sub.2 (SCSR).sub.4 LandM.sub.2 (SCSR).sub.4 L.sub.

Abstract: This invention relates to improvements in certain catalytic reactions, namely, hydrogenation, hydroformylation and carbonylation reactions.