U.S. Geological Survey, MS 205A, 12201 Sunrise Valley Drive, Reston, VA 20192

20 -- SIDESCAN SONAR AND BATHYMETRY SURVEYING SYSTEM SOL 00HQSS0027 DUE 071900 POC Pansy R. Yeatts, (703) 648-7382 E-MAIL: Click here to contact the contracting officer via, pyeatts@usgs.gov. This is amendment 3 to Request for Quotation 00HQSS0027, which was announced in the CBD June 29, 2000. This amendment adds the following specifications to the RFQ and extends the due date response time: 1. The resolution/feature detection rather than the absolute accuracy for the Side Scan Sonar must resolve all targets that exceed 1.0m or 5.0% of the water depth vertically and at least 2m or 10% of the water depth horizontally for the entire swath. 2. The Bathymetry -- Detection of "natural geomorphological" features that exceeds 2m or 10% of the water depth vertically that have horizontal wavelengths of a minimum of 4m or 20% of water depth for the entire swath. 3. The system requirement for side scan depth/range for the side scan must meet or exceed ~10xWD up to 150m slant range per side. The bathymetry depth/range must meet or exceed ~ 8xWD to 30m water depth and then holding at a 200m swath width down to 100m water depth. 4. Ping rates should accommodate no more than 50% wait time after arrival of the last slant range solution, requiring at least 6.7 Hz at 75m slant range, for example. Absolute maximum of 15 Hz. 5. The vessel speed during the surveying will be 5-10 knots. 6. Based on the 20% water depth feature detection requirement, the maximum allowable beam spacing/spreading across the swath is 10% of water depth. 7. The Sonar must be capable of providing wide swath (8-10xWD) reconnaissance bathymetry in support of very-near shore, shallow water surveying for the purpose of geological interpretation of coastal geomorphology (magnitude and orientation of sand ridges, etc.) Hydrographic surveys are not intended. 8. The format (data logged) must be a fully integrated (orientation, heave and refraction corrected) format with an open description. The formats however, must store the data in a ping- indexed manner, so that both geographic position AND along-across coordinates are present (or simply derivable). Must also include travel time and beam depression angle for every beam. Orientation (roll, pitch, heave, gyro) at least once per shot must be retained in this format. Original, navigation solutions must be provided at their original sampling interval with all qualifiers retained. The USGS processing software that will be used to read the data format is SwathEd. A full description of this software can be accessed at http://www.omg.unb.ca/`jhc/SwathEd.html. 9. Empirical refraction adjustment tools will be used to compensate for inadequate knowledge of the water column and any other refraction errors, particularly at the far range. 10. The motion sensor must be co-located to the Sonar to provide for a mobile package that can be aligned on vessels of opportunity and to isolate the system package from any twisting of the hull and pole coupling, or any other side/bow mount movements and vibrations, on the various types of vessels the system will be aligned on. Responses must be received by the revised due date of 19 July 2000, no later than 2:00 PM Eastern Time. Responses shall be in writing, marked with the solicitation number and addressed to Pansy R.Yeatts at US Geological Survey, Acquisition and Federal Assistance, Mail Stop 205A, 12201 Sunrise Valley Drive, Reston, Virginia, 20192. Electronic mail and facsimile transmittal will be accepted, however, telephone confirmation of receipt is suggested. All other terms and conditions remain the same. Posted 07/12/00 (W-SN473708). (0194)

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