Metadata for Flathead Basin 2009 2-Foot Contours

- Identification Information
- Data Quality Information
- Spatial Data Organization Information
- Spatial Reference Information
- Entity and Attribute Information
- Distribution Information
- Metadata Reference Information

Identification Information:

Citation:
  Originator: Watershed Sciences
  Publication date: 11/2010
  Title: Flathead Basin 2009 2-Foot Contours
  Publication place: Helena, MT
  Publisher: Montana State Library
  Online linkage: http://nris.mt.gov/flathead/contour.asp
Abstract:
  2-foot topographic contours of the Flathead Basin, including the Flathead Valley north of Flathead Lake and the immediate areas around Whitefish Lake, Flathead Lake, Swan Lake, and Polson. These contours were derived by automated methods from LiDAR point cloud data collected between September 22 and September 29, 2009.
Purpose:
  Elevation data to be used for floodplain delineation and other landscape analyses.
Time period of content:
  Beginning date: 09/22/2009
  Ending date: 09/29/2009
  Currentness reference: ground condition
Status:
  Progress: Complete
  Maintenance and update frequency: None planned
Access constraints: none.
Use constraints: none.
Point of contact:
  Stephen Story
  Montana DNRC Water Resources Division
  1424 9th Avenue
  Helena, Montana 59620-1601
  Telephone: 406-444-6664
  E-Mail: sestory@mt.gov

Back to Top

Data Quality Information:

Quantitative horizontal positional accuracy assessment:
Vertical positional accuracy report:
  The vertical accuracy of the LiDAR data is described as the mean and standard deviation (sigma ~ ) of divergence of LiDAR point coordinates from 4229 ground survey point coordinates. The root mean square error (RMSE) for vertical accuracy of these control points is provided.
Quantitative vertical positional accuracy assessment:
  Vertical positional accuracy value: 3 centimeters
Lineage:
  Source information:
    Beginning date: 09/22/2009
    Ending date: 09/29/2009
  Process step:
    The LiDAR survey used a Leica ALS50 Phase II laser system. For the Flathead Basin survey site, the sensor scan angle was ±15o from nadir with a pulse rate designed to yield an average native density (number of pulses emitted by the laser system) of 4 points per square meter over terrestrial surfaces.
    A terrain model was produced for the study area. The digital elevation modelswas created from a triangulated irregular network (TIN) of ground classified LiDAR points, however the elevation model has hydrographic feature breaklines enforced.
    3Di West (GeoTerra Mapping Group) collected breaklines for the Flathead basin study area using photogrammetric techniques. The photogrammetric breaklines were used to supplement the LiDAR data in creation of a hydrologically enforced ground model. Hard breaklines were draped to the elevation of the LiDAR derived ground model to co-register the elevation of the photogrammetric breakline with the LiDAR ground class. The stream breaklines were implemented as soft breaklines, and used to detect culverts. Points previously classified as ground above culverts in the LiDAR data were re-classed as non-ground, enabling stream channels to continue flow. Other breaklines, such as top of bank, were used to aid ground classification, and in areas where the LiDAR did not collect a ground point, ground points were added along the breakline.
    The LiDAR DEM was hydrologically enhanced using the photogrammetrically derived breaklines. The breaklines were implemented in the LiDAR data model differently depending on the feature represented. The implementation for each feature is designed to provide the most accurate and hydrologically correct ground model.
    Contour key points were classed out of the ground model every 10 feet to provide more manageable dataset to work with (provided no significant change in Z). Contours were produced through TerraModeler with a Z tolerance of .33 feet. The same breakline rules and resulting ground class for the hydrologically enforced ground model were used as the basis for contour creation. Contour lines (2 ft.) were derived from ground-classified LiDAR point data using Terrasolid LiDAR processing tools in Microstation v.8.01.
  Process step: Dataset copied.
  Process date: 10/23/2010

Back to Top

Spatial Data Organization Information:

Point and vector object information:
  ESRI feature type: Polyline
    ESRI feature count: 2387627

Back to Top

Spatial Reference Information:

Horizontal coordinate system definition:
  Projected coordinate system name: Montana State Plane Coordinates, Feet
  Map projection:
    Map projection name: Lambert Conformal Conic
    Lambert conformal conic:
    Lambert Conformal Conic
    Standard parallel: 45.000000
    Standard parallel: 49.000000
    Longitude of central meridian: -109.500000
    Latitude of projection origin: 44.250000
    False easting: 1968500.000000
    False northing: 0.000000
  Planar distance units: US survey feet
  Geodetic model:
    Horizontal datum name: D_North_American_1983_HARN
    Ellipsoid name: Geodetic Reference System 80
    Semi-major axis: 6378137.000000
    Denominator of flattening ratio: 298.257222
Altitude system definition:
  Altitude datum name: NAVD 88 Geoid03
  Altitude resolution: 0.000100
  Altitude distance units: Feet
  Altitude encoding method:
    Explicit elevation coordinate included with horizontal coordinates

Back to Top

Entity and Attribute Information:

Entity type label: Contour
Entity count: 0
  Attribute label: elevation
    Attribute definition: Elevation of line in meters
  Attribute label: Shape_Length
    Attribute definition: Length of feature in internal units.
    Attribute domain: Positive real numbers that are automatically generated.

Back to Top

Distribution Information:

Distributor:
  Montana State Library
  PO Box 201800
  Helena, MT 59620-1800
  Telephone: 406-444-5355
  E-Mail: nris@mt.gov
Resource description: Downloadable Data
Standard order process:
  Digital form:
    Format name: ESRI File Geodatabase
    Online option:
    http://nris.mt.gov/flathead/contour.asp

Back to Top

Metadata Reference Information:

Metadata date: 05/11/2010
Metadata contact:
  Watershed Sciences
  257B SW Madison Ave.
  Corvallis, Oregon 97330
  Telephone: (541) 752-1204

Back to Top