I.   IDENTIFICATION INFORMATION

          1.   Theme: Bathymetric surface, Yakutat Bay
               Data set name: yak_bath
          
          2.   Originator:  Interrain Pacific
          
          3.   Date: 2/15/97
          4.   Edition:
          
          5.   Description:  This layer contains an interpolated
               bathymetric surface for Yakutat Bay, Alaska.  This
               coverage interpolated from NOS bathymetric point
               data.  Interrain Pacific augmented the NOS data
               with information from NOAA nautical charts for
               some areas of the outer coast.


          6.   Data Set Status:

               ___In preparation, Anticipated Completion_____
               
               _X_Completed and operational
               
               ___On going; Update Frequency:____

               Data Set Status Comments:

          7.   Geographic Coverage Description:  This bathymetric
               layer covers Glacier Bay and Icy Strait from
               Excursion Inlet to Cape Spencer.


               Please check appropriate USGS 1:250,000 maps:

       ___Atlin            ___Juneau      _X_Mount Fairweather
       ___Port Alexander        ___Skagway     ___Sumdum
       _X_Yakutat
       
       

          8.   West Bounding Coordinate:  149 30 00 W
          
          9.   East Bounding Coordinate:  145 00 00 W
          
          10.  North Bounding Coordinate:  61 30 00 N
          
          11.  South Bounding Coordinate:  59 45 00 N
          
          12.  Theme keywords:
               _X_bathymetry
               _X_oceanography
               _X_shoreline


          13.  Access Restrictions:   Data transfer costs will be
               based on staff time and media costs.
          
          14.  Use Restrictions: Data may not be sold.
          
          15.  Processing Information:
               Software used to automate: ARC/INFO
               Software Version:  7.x
               Hardware Platform:  SUN
               Operating System used:  UNIX
               File Name: bath_ln
               File Size: 73 mb
               Feature Type:

               ___Point (data point) ___Line (Arc) ___Polygon
               _X_Grid ___Text ___Other

          16.  Raster File Form
          ___ADRG        ARC Digitized Raster Graphic (ARC/INFO
                         GRID format)
          ___ADRI        ARC Digitized Raster Imagery
          ___BIL         Imagery, band interleaved by line
          ___BIP         Imagery, band interleaved by pixel
          ___BSQ         Imagery, band sequential
          ___DEM         USGS Digital Elevation Model
          ___ERD74       ERDAS image files version 7.4
          ___ERD81       ERDAS IMAGINE image files, ver8.1
          ___GRAS3       GRASS (Geographic Resources Analysis
                         Support System)v3
          ___GRAS4       GRASS (Geographic Resources Analysis
                         Support System) v4
          ___IDL         Interactive Data Language image file
          ___MOSS        Multiple Overlay Statistical System
                         export file
          ___TIFF        Tagged Image File Format
          _X_Other       Arc/Info Grid


II.  DATA QUALITY INFORMATION

          1.   Attribute Accuracy Explanation:  General
               comparisons have been conducted between this
               coverage and NOAA nautical charts, and indicated
               reasonably good agreenment.  During the processing
               of data from the NOS Hydrographic CD, we several
               many points with spurious data.  Particular
               examples are points indicating a depth >0 where no
               land was present.  The slope (bath_slp) layer was
               particularly useful in identifying spurious data.
               For the purpose of the bathymetric surface, all
               points with a positive depth (i.e. land) were
               deleted.  This fixed most problems, but some may
               still exist.  In addition, in areas without NOS
               surveys, we extracted points based no digital
               nautical charts.  This helped complete the surface
               in a very general way, but are not as accurate as
               areas with formal NOS hydrographic data.

          2.   Attribute Accuracy:  __________%
               __X__Unknown_____
               _ _no accuracy assessment performed on dataset


          3.   Description of Data Completeness:.

          4.   Minimum Mapping Unit: _25m______________   _
               __Unknown ____n/a
          
          5.   Positional Accuracy Comments:  The NOS point data
               used to generate the gridded data includes data
               from many years.  Positional accuracy of the point
               data is variable depending on the technology used
               to geo-reference.  The depth and units of
               measurement for depth of the point data imply
               different levels of accuracy (i.e., 6 3/4 fathoms
               would likely have lower vertical accuracy than
               63.4 meters).  The number and position of points
               used to generate the gridded data is not known.
               The gridding process generalizes the point data.

          6.   Source Information:

               National Geophysical Data Center, National Oceanic
               and Atmospheric Administration, 325 Broadway,
               Boulder CO 80303-3328 (303)497-6141. Contact
               person: Lt. Todd Bergren

          7.   Date of Source Data: VARIES

          8.   Scale of Source Data: >80% of all NOS Hydrographic
               survey points were within 25m of their nearest
               neighbor.

          9.   Data Processing Description:  Point data was
               extracted from the NOS Hydrographic CD, and
               standardized into a consisten horizontal datum
               (NAD27).  Interrain Pacific hand-digitized holes
               in the NOS data from NOAA digital nautical charts,
               and used ARC/INFO TIN routines to develop a
               surface interpolation.  Subsequently, Interrain
               Pacific created a bathymetric grid based on the
               TIN representation of the combined bathymetric
               databases.


III. SPATIAL DATA ORGANIZATION INFORMATION

          1.   Data Structure:

               ___point (x,y)
               ___vector(line >1 x,y)
               _X_raster (grid cell)
               ___tin (3 dimensional x,y,z)
               ___Other__________

          2.   Raster File Row: 4278
          
          3.   Raster File Column: 4123
          
          4.   Raster File Vertical:
          
          5.   Raster File Number of Bytes per Pixel:
          
          6.   Raster file origin: X=373892.599, Y=6446838.998


IV.  SPATIAL REFERENCE INFORMATION


          1.   Map Projection Name
          Projection: UTM
          Zone:   8
          Datum:  NAD27
          Units:   METERS
          Spheroid:  Clarke1866


V.   ENTITY AND ATTRIBUTE INFORMATION

          1.   Attribute Labels:  VALUE indicated DEPTH in METERS

          2.   Attribute Definition Source:

               NOAA/NGDC E/GC3; 325 Broadway, Boulder CO 80303
               (303) 479-6376 (Contact person: LT. Lee M. Cohen)


VI.  DISTRIBUTION INFORMATION

          1.   Distributor:  Interrain Pacific

          2.   Distribution Liability:  This information should
               NOT be used for navigation.  Interrain Pacific
               makes no express or implied warranties with
               respect to the character, fitness, function,
               accuracy, or capabilities of the information
               presented or the appropriateness for any users
               purposes.  In no event will Interrain Pacific be
               liable for any incidental, indirect, special,
               consequential or other damages suffered by the
               user of this information or other person.
          
          3.   Standard Order Process:  Data will be provided on
               tape or CD-ROM based on a written request.
          
          4.   Hardware media type:  8mm tape, CD-ROM.
          
          5.   File Decompression Technique:  None.
          
          6.   Decompressed Data Transfer Size:


VII. METADATA REFERENCE INFORMATION
          
          1.   Metadata Date:  March 3, 1997
          
          2.   Metadata Contact:  Interrain Pacific


VIII.     CONTACT INFORMATION

          1.   Primary Contact Person:  Interrain Pacific
          
          2.   Contact Mailing Address:
          1200 NW Front Ave., Suite 470A
          Portland, OR  97209
          
          3.   Contact Voice Telephone:  (503) 226-8108
          
          4.   Contact Facsimile Telephone:  (503) 226-8110
          
          5.   Contact Electronic Mail Address:
               interrain@igc.apc.org