smi1m.tiff - Sidescan sonar image of San Miguel Island

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

Title: smi1m.tiff - Sidescan sonar image of San Miguel Island

Abstract:

The sidescan sonar image of the nearshore seafloor (0 to 100 m water depths) of the Big Sycamore reserve area was mosaicked from data collected in 1998. A Klein 2000 sidescan system was used for geophysical surveying. A Triton Elics Isis brand side-scan data recording system was used on the cruise. The 1998 survey was navigated with a Leica Differential Global Positioning System (DGPS) which provided a ship position with accuracy of 1-5 m in DGPS mode. At times during the cruise differential signal was interrupted. In non-differential mode, the receiver provided a position with 30-50 m accuracy. A KVH Industries Inc. azimuth digital gyro-compass provided ship headings with 0.5 degree accuracy. Navigation data were recorded using Yo-Nav version 1.19 (Gann, 1992). The sidescan fish was towed approximately 30 m above the seafloor. The distance of the fish behind the ship was not known during this survey and must be estimated when the data are processed in order to produce the sidescan image mosaics. The resolution of the processed data mosaics is 0.2 m. The data are presented here at a resolution of 1 m. This is one of a collection of digital files of a geographic information system of spatially referenced data related to the USGS Coastal and Marine Geology Program Nearshore Benthic Habitat Mapping Project. See <http://walrus.wr.usgs.gov/nearshorehab> for more information.

Supplemental_Information:

Additional information about the field activities from which this data set was derived are available online at <http://walrus.wr.usgs.gov/infobank/b/b198sc/html/b-1-98-sc.meta.html>

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology.

1. How should this data set be cited?

   Cochrane, Guy R. , and Gabel, Greg S. , 2002, smi1m.tiff - Sidescan sonar image of San Miguel Island: USGS Open-File Report USGS OFR 03-85, U.S. Geological Survey, Menlo Park, CA.

   Online Links:

   • <URL:http://geopubs.wr.usgs.gov/open-file/of03-85>

   This is part of the following larger work.

   Cochrane, Guy R. , Nasby, Nicole, Reid, Jane A. , Waltenberger, Ben, and Lee, Kristen, 2003, Nearshore Benthic Habitat GIS for the Channel Islands National Marine Santuary and Southern California State Fisheries Reserves, Volume 1.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -120.29167

   East_Bounding_Coordinate: -120.45833

   North_Bounding_Coordinate: 34.025

   South_Bounding_Coordinate: 33.96667

3. What does it look like?

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 1998

   Ending_Date: 2003

   Currentness_Reference: Ground Condition

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: map

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

      This is a Raster data set. It contains the following raster data types:

      • Dimensions 6865 x 15564, type Pixel

   2. What coordinate system is used to represent geographic features?

7. How does the data set describe geographic features?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Guy R. Cochrane
   • Greg S. Gabel

2. Who also contributed to the data set?

3. To whom should users address questions about the data?

   Guy R. Cochrane
   United States Geological Survey (USGS)
   Geophysicist
   USGS, MailStop 999, 345 Middlefield Road
   Menlo Park, CA 94025-3561
   USA
   

   (650) 329-5076 (voice)
   (650) 329-5190 (FAX)
   gcochrane@usgs.gov
   

These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information about the shallower areas of S. California coast.

1. From what previous works were the data drawn?

2. How were the data generated, processed, and modified?

   Date: 15-Nov-2000 (process 1 of 17)

   xtfin FILES> /work1/gregg/b1-99-sc/L3=/work1/gregg/b1-99-sc/Mig3.XTF PARAMS> LCHAN=2,RCHAN=1 PARAMS> RATE2

   Date: 05-Dec-2000 (process 2 of 17)

   navmerge FILES> /work1/gregg/b1-99-sc/L3,/work1/gregg/b1-99-sc/b199sc PARAMS> LATLON

   Date: 06-Dec-2000 (process 3 of 17)

   snrshade FILES> /work1/gregg/b1-99-sc/L3_snr=/work1/gregg/b1-99-sc/L3 PARAMS> MIN=1,MAX=254

   Date: 06-Dec-2000 (process 4 of 17)

   navflt FILES> /work1/gregg/b1-99-sc/L3_snr PARAMS> NR=9,ALTITUDE

   Date: 06-Dec-2000 (process 5 of 17)

   navflt FILES> /work1/gregg/b1-99-sc/L3_snr PARAMS> NR=101,HEADING

   Date: 06-Dec-2000 (process 6 of 17)

   slr2gr FILES> /work1/gregg/b1-99-sc/L3_snr_sg=/work1/gregg/b1-99-sc/L3_snr PARAMS> PIXRES=0.1,NANGLE=90,FANGLE=0.5,LOFFSET=0,ROFFSET=0

   Date: 06-Dec-2000 (process 7 of 17)

   shade FILES> /work1/gregg/b1-99-sc/L3_snr_sg_sh=/work1/gregg/b1-99-sc/L3_snr_sg PARAMS> MULT,MIN=1,MAX=254,SL=1,EL=8000

   Date: 06-Dec-2000 (process 8 of 17)

   destripe FILES> /work1/gregg/b1-99-sc/L3_snr_sg_sh_ds2=/work1/gregg/b1-99-sc/L3_snr_sg_sh PARAMS> LNL=501,LNS=501,LLOW=1,LHIGH=254,HNL=501,HNS=31,HLOW=1,HHIGH=254

   Date: 06-Dec-2000 (process 9 of 17)

   deltav FILES> /work1/gregg/b1-99-sc/L3_dv=/work1/gregg/b1-99-sc/L3_pr PARAMS> PIXRES=0.1

   Date: 11-Oct-20007 (process 10 of 17)

   snrgeom FILES> /work1/gregg/b1-99-sc/L3_gm=/work1/gregg/b1-99-sc/L3_dv PARAMS> UTM PARAMS> WGS84 PARAMS> ZONE=10,SCALE=0.9996 PARAMS> SLAT=33.96667,SLON=-120.45833,ELAT=34.025,ELON=-120.29167,ROTATION=0,PIX RES=0.2

   Date: 17-Jan-2001 (process 11 of 17)

   digmos FILES> /work1/gregg/b1-99-sc/L3_mos=/work1/gregg/b1-99-sc/L3_gm PARAMS> PROJECTION PARAMS> SLAT=33.96667,SLON=-120.45833,ELAT=34.025,ELON=-120.29167

   Date: 18-Jan-2001 (process 12 of 17)

   digmos FILES> /work1/gregg/b1-99-sc/L3_moz=/work1/gregg/b1-99-sc/L3_mos PARAMS> MANUAL PARAMS> ONL=34325,ONS=77818 PARAMS> ISL=1,ISS=1,IEL=34325,IES=77818,OSL=20,OSS=180

   Date: 18-Jan-2001 (process 13 of 17)

   maskim FILES> /work1/gregg/b1-99-sc/L3_msk=/work1/gregg/b1-99-sc/L3_moz,/work1/gregg/b1-99-sc/L3_ras PARAMS>

   Date: 18-Jan-2001 (process 14 of 17)

   digmos FILES> /work1/gregg/b1-99-sc/b1-99-sc_mos=/work1/gregg/b1-99-sc/L3_msk PARAMS> ISL=1,ISS=1,IEL=34325,IES=77818,OSL=1,OSS=1 PARAMS> INPUT

   Date: 18-Jan-2001 (process 15 of 17)

   digmos FILES> /work1/gregg/b1-99-sc/b1-99-sc_mos2=/work1/gregg/b1-99-sc/b1-99-sc_mos PARAMS> MANUAL PARAMS> ONL=34325,ONS=77818 PARAMS> ISL=15,ISS=100,IEL=34325,IES=77818,OSL=1,OSS=1

   Date: 18-Jan-2001 (process 16 of 17)

   filter FILES> /work1/gregg/b1-99-sc/b1-99-sc_mosf=/work1/gregg/b1-99-sc/b1-99-sc_mos2 PARAMS> LPFZ PARAMS> NL=3,NS=3,LOW=1,HIGH=255,PERCENT=0,MULT=1

   Date: 18-Jan-2001 (process 17 of 17)

   scale FILES> /work1/guy/mig/smi1m=/work1/guy/mig/smi_mos PARAMS> NL=6865,NS=15564

3. What similar or related data should the user be aware of?

1. How well have the observations been checked?

   Accuracy Unknown

2. How accurate are the geographic locations?

   On the order of 10 meters.

3. How accurate are the heights or depths?

4. Where are the gaps in the data? What is missing?

   Completeness unknown

5. How consistent are the relationships among the observations, including topology?

   Logical Consistency untested.

Are there legal restrictions on access or use of the data?

Access_Constraints: None

Use_Constraints:

Please recognize the U.S. Geological Survey (USGS) as the source of this information.

Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.

The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.

This information is not intended for navigational purposes. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

1. Who distributes the data set? (Distributor 1 of 1)

   United States Geological Survey (USGS)
   c/o Guy R. Cochrane
   Geophysicist
   USGS, MailStop 999, 345 Middlefield Road
   Menlo Park, CA 94025-3561
   USA
   

   (650) 329-5076 (voice)
   (650) 329-5190 (FAX)
   gcochrane@usgs.go
   

2. What's the catalog number I need to order this data set?

3. What legal disclaimers am I supposed to read?

   Please recognize the U.S. Geological Survey (USGS) as the source of this information.

   Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.

   The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.

4. How can I download or order the data?

Dates:

Last modified: 16-Jan-2003
Last Reviewed: 15-Aug-2003

Metadata author:

United States Geological Survey (USGS)
c/o Guy R. Cochrane
Geophysicist
USGS, MailStop 999, 345 Middlefield Road
Menlo Park, CA 94025-3561
USA

(650) 329-5076 (voice)
(650) 329-5190 (FAX)
gcochrane@usgs.gov

Metadata standard:

FGDC Content Standards for Digital Geospatial Metadata ("CSDGM version 2") (FGDC-STD-001-1998)