| 主权项 |
1. A towed system for underwater electromagnetic prospecting for use with a seaward vessel, the towed system comprising:
a first portion located on the vessel, the first portion including a controller, a common system clock and a power supply system, the common system clock being configured to maintain and periodically transmit a master clock signal following deployment; a second towed portion for submersion in the water, the second towed portion for transmitting an electromagnetic signal and receiving a corresponding electromagnetic signal, wherein the second towed portion further comprises: a towed instrument container connected to a tow cable, the towed instrument container for transmitting the electromagnetic signal; and a plurality of receiver assemblies, connected to the towed instrument container with a main cable, the plurality of receiver assemblies for receiving the corresponding electromagnetic signal, and the plurality of receiver assemblies is arranged in a logarithmically spaced array oriented substantially parallel to a surface upon which the towed system is being towed or is in close proximity to, each receiver assembly including at least (i) a precision clock synchronized periodically with the master clock following deployment, and (ii) digital circuitry configured for stacking a plurality of received electromagnetic signals such that random noise can be reduced during processing of the plurality of received electromagnetic signals; and the tow cable connecting the first portion with the second portion, the tow cable including at least one pair of suitable conductors for delivering to the second portion power generated by the first portion and at least one optical fiber for carrying data communications between the first portion and the second portion; wherein each receiver assembly of the plurality of receiver assemblies is configured as a module separate from the other receiver assemblies and is removably coupled with another receiver assembly of the plurality of receiver assemblies. |
