Prospects for Euro-Indian space cooperation

This is the executive summary of a report prepared for the European Commission by LD consultants on the status of India's space industry and the prospects for European firms to invest in it. India has impressive launch capabilities, telecommunications and disaster warning satellites but commercialization of its activities is occurring only slowly. There are many opportunities for joint ventures with Europe (which must not let the USA consolidate its superior position in the broadcasting field) but issues of technology transfer and India's unhappiness with the MTRC must first be resolved. As well as selling products and services, Europeans should also be prepared to buy those Indian components that are available more competitively.     

Frequency stability in adaptive retrodirective arrays

The frequency stability of communications or remote sensing systems using phase conjugation as a means of retrodirective signaling is developed under the influence of constant rectilinear motion. The results indicate that for dynamic mobile platforms such as aircraft, helicopters, and ground vehicles the retrodirective properties of phase conjugating arrays are not guaranteed due to a possible instability of the frequency. It is shown that the frequency transmitted by each platform has a dependence on the open loop gains of the transceivers on each platform in the link. Fast and accurate reconstruction of the phase of the signal requires a high open loop gain, however, too high a gain will cause instability and eventual loss of lock. Design tradeoffs are discussed.