U.S. Geological Survey, Branch Of Acquisition and Federal Assistance, Box 25046, Denver Federal Center, Denver, CO 80225-0046

T -- HELICOPTER GEOPHYSICAL SURVEY DUE 091597 POC Robert Valdez (303) 236-5900 EXT 424 Concerns having the ability to furnish the following helicopter electromagnetic survey, as described herein are requested to give written notification (including the telephone number for a point of contact) to the procuring office above within forty-five (45) calendar days from the date of this synopsis. Area to be Flown: 730 traverse miles (1175 km) of West Boulder Creek area, Jefferson and Powell counties, Montana. Helicopter electromagnetic and magnetic survey to be flown NW-SE at 0.124 mile (200 m) line spacing and 200-300 ft. (60-90 m) above the terrain and water. Three evenly spaced control lines are to be flown NE-SW at 200-300 ft (60-90 m) above the terrain and water. Differential GPS navigation is required. This is an extension of an area flown in 1996. May include collection of VLF data and standard processing of VLF data. Optional deliverables are flight path; magnetic field contour map; radar altimeter map; multiparameter profiles; EM contour maps (apparent resistivity); EM anomaly picks (raw table); magnetic processing of EM data. In order for a valid comparison to be made between the previously acquired data and the new data set, it is critical that the measurements be made with equipment that can closely duplicate the 1996 survey. An electromagnetic (EM) system with at least five frequencies and a multi-coil (coaxial and coplanar) geometry shall be used. The equipment shall measure inphase (I) and quadrature (Q) response channels. EM coil orientations and frequencies are specified in order to provide compatible data with the HEM survey flown in 1996. Coil separation shall be eight (8) meters for all but the 56000 pair which shall be 6.3 meters. The actual frequencies in the new survey shall be within plus or minus five (5) percent of the old survey values. Based on information available at this time, and in accordance with 41 U.S.C. 253(c)(1), implemented by FAR 6.302-1, the Government considers the item specified as a sole source from Dighem Surveys, Mississauga, Ontario and proposes to negotiate a contract with that firm on that basis. However, should additional sources be identified, they will be considered. Firms who feel that they can furnish the required item or its functional equivalent (based upon the criteria specified herein) are invited to submit in writing an affirmative response to this announcement. An affirmative response would include literature, brochures and such other materials which correspond to the required items stated herein. This information will be evaluated and used to determine if competitive opportunities exist. Since no solicitation document exists, requests for such documentation without accompanying information will be considered non- responsive to this request without further consideration. This notice may represent the Government's only official notice of this procurement. See Notes 22.***** -- (0211)

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