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YFO_LiDAR_bathymetry_2004_2005

Frequently-anticipated questions:

What does this data set describe?

How should this data set be cited?
What geographic area does the data set cover?
What does it look like?
Does the data set describe conditions during a particular time period?
What is the general form of this data set?
How does the data set represent geographic features?
How does the data set describe geographic features?
Who produced the data set?
Who are the originators of the data set?
Who also contributed to the data set?
To whom should users address questions about the data?
Why was the data set created?
How was the data set created?
From what previous works were the data drawn?
How were the data generated, processed, and modified?
What similar or related data should the user be aware of?
How reliable are the data; what problems remain in the data set?
How well have the observations been checked?
How accurate are the geographic locations?
How accurate are the heights or depths?
Where are the gaps in the data? What is missing?
How consistent are the relationships among the data, including topology?
How can someone get a copy of the data set?
Are there legal restrictions on access or use of the data?
Who distributes the data?
What's the catalog number I need to order this data set?
What legal disclaimers am I supposed to read?
How can I download or order the data?
Who wrote the metadata?
 
What does this data set describe?
Title: YFO_LiDAR_bathymetry_2004_2005
Abstract:
Bathymetric LiDAR collected on seven reaches (Easton, Upper Kittitas, Lower Kittitas, Naches, Sunnyside, Prosser, Chandler) of the Yakima River Basin in 2004 and 2005.
 
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How should this data set be cited?

UCAO; Bureau of Reclamation, 08/26/2008,
YFO_LiDAR_bathymetry_2004_2005.

Online Links:

  • \\140.218.41.238\gis\GIS_Database\UCAO_Topography_GIS_DB.gdb
 
What geographic area does the data set cover?
West_Bounding_Coordinate: -121.183644
East_Bounding_Coordinate: -119.503566
North_Bounding_Coordinate: 47.243214
South_Bounding_Coordinate: 46.187999

 

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What does it look like?
 
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Does the data set describe conditions during a particular time period?

Beginning_Date: Sep-2004
Beginning_Time: unknown
Ending_Date: May-2005
Ending_Time: unknown
Currentness_Reference: ground condition

 
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What is the general form of this data set?

Geospatial_Data_Presentation_Form: vector digital data

 
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How does the data set represent geographic features?
How are geographic features stored in the data set?
This is a Vector data set. It contains the following vector data types (SDTS terminology):
Entity point (3748897)
What coordinate system is used to represent geographic features?
The map projection used is Lambert Conformal Conic.

Projection parameters:

    Standard_Parallel: 45.833333
    Standard_Parallel: 47.333333
    Longitude_of_Central_Meridian: -120.500000
    Latitude_of_Projection_Origin: 45.333333
    False_Easting: 1640416.666667
    False_Northing: 0.000000

Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.000328
Ordinates (y-coordinates) are specified to the nearest 0.000328
Planar coordinates are specified in survey feet

The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.

Vertical_Coordinate_System_Definition:

    Altitude_System_Definition:
    Altitude_Datum_Name: North American Vertical Datum of 1988
    Altitude_Distance_Units: feet
 
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How does the data set describe geographic features?

YFO_LiDAR_bathymetry_2004_2005

OBJECTID

Internal feature number. (Source: ESRI)

Sequential unique whole numbers that are automatically generated.


Shape
Feature geometry. (Source: ESRI)
Coordinates defining the features.
elevation
z coordinate in the NAVD 88 vertical coordinate system

Range of values
Minimum: 466
Maximum: 2140
Units: feet

ELEVATION
Elevation_Uncorrected
uncorrected z coordinate in the NAVD 88 vertical coordinate system

LOCATION
name of the reach the data is located within

Value Definition
Chandler  
Easton  
Lower Kittitas  
Upper Kittitas  
Prosser  
Naches  
Sunnyside  
 


Formal codeset
Codeset Name: Easton


Formal codeset
Codeset Name: Easton

Entity_and_Attribute_Overview: Attributes consist of the x, y, z locational coordinates.

 
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Who produced the data set?
Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  • UCAO; Bureau of Reclamation
 
Who also contributed to the data set?
Reclamation's Technical Service Center
 
To whom should users address questions about the data?

Upper Columbia Area Office, USDI Bureau of Reclamation
c/o UCAO GIS Coordinator
GIS Specialist
US Bureau of Reclamation
Box 1749
1917 Marsh Road
Yakima, WA 98907-1794
USA

509-575-5848 (voice)
509-454-5611 (FAX)
spatialdata@pn.usbr.gov

Hours_of_Service: 0730-1600
Contact_Instructions:
Call or e-mail data requests to contacts provided. Additional contact information is available at <http://spatialdata.pn.usbr.gov>
 
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Why was the data set created?
To create an elevation model in support of the Yakima River Basin Water Storage Feasability Study (YRBWSFS) hydraulic modeling effort. The hydraulic modeling was conducted to help determine fish habitats at different flow levels.
 
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How was the data set created?
(source 1 of 1)
, empty.
Source_Contribution: All original mapping data.
  1. From what previous works were the data drawn?
    (source 1 of 1)
    , empty.

    Source_Contribution: All original mapping data.

How were the data generated, processed, and modified?
(process 1 of 3)
This bathymetry was collected and processed by Fugro Pelagos,Inc. using a SHOALS-1000T LASER (manufactured by Optech, Inc.) sensor capable of penetrating water using a blue-green LASER. Terrestrial measurements are also possible with this unit although none was acquired with this bathymetry. The data was processed with Optech software using what is being called the "Inland Water Algorithm". This algorithm was developed to process those returns from depths from less than approximately 4.9 feet (1.5 meters). The "Inland Water Algorithm" processes data acquired from depths to approximately 13 feet (4 m). The Sept. 2004 data was the first application of this algorithm and use of the SHOALS-1000T in shallow water riverine environments.
The published specification and accuracies for the SHOALS-100T are as follows: The SHOALS-1000T is capable of recording x-y-z data at a rate of 1000 Hz with a sounding density of 6.6x6.6, 9.8x9.8, 13.1x13.1 and 16.4x16.4 feet (2x2, 3x3, 4x4 or 5x5 m). The point data for the bathymetry meets Order 1 accuracy standards of the International Hydrographic Organization (IHO) with a horizontal accuracy of 8.2 feet (2.5 m) and a vertical accuracy of 0.8 feet (0.25 m, 1 sigma). For more information regarding instrument specifications visit <http://www.optech.on.ca>. This site also contains information on the history of the development of the SHOALS unit. For more information on hydrographic surveying accuracies and the IHO refer to chapter two of the U.S. Army Corps of Engineers Hydrographic Survey manual at <http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-2-1003/toc.htm>.
It is likely that water clarity is the single most limiting factor for collecting bathymetric data with LiDAR. The minimum required clarity is measured with a Secchi disc and is called the Secchi depth. A Secchi disc is available in various weights and diameters (approximately 8 - 20 inches, 20 - 50 cm) with the circle typically divided into four evenly divided pie-shaped wedges in alternating black and white. The Secchi depth is determined by lowering the disc into the water column and recording the depth at which the black and white portions of the disc can no longer be distinguished. The minimum visibility requirement for successful LiDAR penetration using the SHOALS-1000T is 2.5 times the Secchi depth up to a depth of 164 ft (50 m) (www.optech.on.ca).
The LASER is not capable of penetrating the water column where bubbles are present, such as white water conditions. The LASER is also incapable of penetrating vegetation, whether that vegetation is growing under the water surface or overhanging above the surface. These limitations are very similar to the limitations of SONAR when operated from a boat. Bubbles foul acoustic signals to the same extent as optic signals. Overhanging vegetation or tall vegetation near the channel banks often prohibits the reception of a sufficient number of satellites or signal from the base station when performing a SONAR survey with RTK GPS surveying equipment.
Ground truth data was collected with RTK GPS at a minimum of one location per reach flown. For the Lower Kittitas data set, there was additional survey data to use for comparison that was collected in August 2003 by SONAR and RTK GPS surveying equipment mounted on a raft. Using these data, a statistical analysis was performed for each data set to determine precision and accuracy. From these analyses conclusions were made regarding the bias and recommended adjustments to the data.
It was determined that the best method for adjusting the elevations provided by the LiDAR is to correct by an amount equal to the median value of the residuals obtained by subtracting the LiDAR elevations from the ground truth elevations. Reasons for the bias are currently unknown and will be investigated by personnel at Reclamation, Fugro Pelagos and Optech. For all but the Lower Kittitas Reach, the bias is approximately +0.5 feet (0.15 m). The Lower Kittitas reach has a bias of +1.5 feet (0.46 m). The advertised precision of the LiDAR is +/- 0.83 feet (0.25 m). Standard deviations from the statistical analysis range from 0.49 feet (0.15 m) to 0.85 feet (0.26 m).
The following is a statistical description of the data comparison (in meters): Chandler Reach: mean = 0.19; median = 0.23; standard deviation = 0.18; number of samples = 375; RMSE = 0.26 Easton Reach: mean = 0.15; median = 0.14; standard deviation = 0.22; number of samples = 163; RMSE = 0.27 Lower Kittitas Reach: mean = 0.24; median = 0.26; standard deviation = 0.35; number of samples = 56; RMSE = 0.42 Upper Kittitas Reach: mean = 0.19; median = 0.20; standard deviation = 0.12; number of samples = 374; RMSE = 0.23 Naches Reach: mean = 0.26; median = 0.27; standard deviation = 0.11; number of samples = 341; RMSE = 0.29 Prosser Reach: mean = 0.17; median = 0.16; standard deviation = 0.15; number of samples = 407; RMSE = 0.22 Sunnyside Reach: mean = 0.16; median = 0.14; standard deviation = 0.15; number of samples = 358; RMSE = 0.22
The data has already been corrected by the recommended amounts.
Person who carried out this activity:
Reclamation
c/o Hydrologic Engineer
Sixth and Kipling; Building 67; Room 152
Denver, CO 80225-0007
USA

303-445-2073 (voice)
303-445-6301 (FAX)

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(process 2 of 3)
Metadata imported.

Data sources used in this process:

  • C:\DOCUME~1\eyoung\LOCALS~1\Temp\xml967.tmp
(process 3 of 3)
Dataset copied.

Data sources used in this process:

  • \\IBR1EYOUNGD01\C$\Data_2_SDE_prep\UCAO_Topography_GIS_DB.gdb
 
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What similar or related data should the user be aware of?
 
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How reliable are the data; what problems remain in the data set?
 
How well have the observations been checked?
The only attributes refer to the z coordinates or reach locations. The attribute accuracies for the z coordinates are directly tied to the accuracy of the data set. These attributes were cross checked by TSC; Reclamation employees for correctness. The reach locations were added by UCAO; Reclamation employees and double checked.
 
How accurate are the geographic locations?
The horizontal accuracy value is based on the published accuracies for the equipment used. However, it is believed that the accuracy values are greater than those listed.
 
How accurate are the heights or depths?
The vertical accuracy value is based on the published accuracies for the equipment used. However, it is believed that the accuracy values are greater than those listed.
The following is a summary of the accuracies found by comparing the raw data to surveyed locations. For all but the Lower Kittitas Reach, the bias is approximately +0.5 feet (0.15 m). The Lower Kittitas reach has a bias of +1.5 feet (0.46 m). Standard deviations from the statistical analysis range from 0.49 feet (0.15 m) to 0.85 feet (0.26 m).
This data has been corrected to take into account the amount equal to the median value of the residuals of each reach obtained by subtracting the LiDAR elevations from the ground truth elevations. For more information, see the process section.
The elevational accuracy value could therefore be closer to 0.1.
 

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

Data set was created to cover portions of the Yakima and Naches River. The areas designated were completely covered.
 
How consistent are the relationships among the observations, including topology?

All data collection was conducted by the same source (Fugro Pelagos,Inc). The finished data was cross checked by TSC; Bureau of Reclamation staff for correctness. As part of the process, data was compared against field surveys conducts at the same time as the data collection flight. For further information, see the 'Process' description.

 
How can someone get a copy of the data set?
Are there legal restrictions on access or use of the data?
Access_Constraints:
The USDI Bureau of Reclamation (Reclamation) provides public domain spatial data without restrictions. Access to spatial data that are considered 1) works in-progress, 2) for internal use, or 3) confidential, sensitive, or private may be restricted. Access to such data may require a Freedom of Information Act (FOIA) request. For further information, contact the Geospatial Data Administrator (see Point of Contact info).
Use_Constraints:
The USDI Bureau of Reclamation (Reclamation) provides spatial data """"""""as-is"""""""" without warranty of any kind, expressed or implied, including but not limited to, any warranties of fitness for a particular purpose. The burden for determining fitness for use lies entirely with the user. In no event will the producers of Reclamation spatial data be liable for any damages arising from the use of, or the inability to use, these data. The user assumes all responsibility for spatial and attribute accuracy, completeness, validity, and appropriateness with regard to the suitability of these spatial data for any specific use or application, and such use or application is at the user?s own risk.
 
Who distributes the data set? (Distributor 1 of 1)
Upper Columbia Area Office
USDI Bureau of Reclamation
GIS Specialist

US Bureau of Reclamation
Box 1749
1917 Marsh Road
Yakima, WA 98907-1794
USA

509-575-5848 (voice)
509-454-5611 (FAX)
spatialdata@pn.usbr.gov

Hours_of_Service: 0730-1600
Contact_Instructions:
Call or e-mail data requests to contacts provided. Additional contact information is available at <http://spatialdata.pn.usbr.gov>
 
What's the catalog number I need to order this data set?
Downloadable Data
 
What legal disclaimers am I supposed to read?
The USDI Bureau of Reclamation (Reclamation) provides spatial data ""as-is"" without warranty of any kind, expressed or implied, including but not limited to, any warranties of fitness for a particular purpose. The burden for determining fitness for use lies entirely with the user. In no event will the producers of Reclamation spatial data be liable for any damages arising from the use of, or the inability to use, these data. Reclamation liability is limited to providing a replacement copy for requested data sets that are not readable upon receipt.
The user assumes all responsibility for spatial and attribute accuracy, completeness, validity and appropriateness with regard to the suitability of these spatial data for any specific use or application, and such use or application is at the user?s own risk.
Spatial data provided by the Reclamation are public domain, and the recipient may not assert any proprietary rights thereto nor represent data sets as other than government-produced data.
 
How can I download or order the data?
Cost to order the data:
No fees for electronic download. Processing, media, and shipping fees may apply for CD-ROM requests.
 

Special instructions:
Contact Geospatial Data Administrator or GIS Coordinator for custom data requests.

 
How long will it take to get the data?
Processing time and delivery will vary depending on the size and complexity of the request.
 
Availability in non-digital form:
Some data requests can be fulfilled through existing or custom prepared cartographic products. Color-plotted maps are the most common delivery product.
 
Cost to order the data:
Actual costs to produce cartographic products, including labor, plotting costs, and shipping.
 
Special instructions:
Contact the Geospatial Data Administrator or GIS Coordinator to request non-digital data products.
 
How long will it take to get the data?
Processing time will vary with the specific request.
 
Is there some other way to get the data?
Contact Geospatial Data Administrator or GIS Coordinator for custom data requests.
 
Who wrote the metadata?
Dates:
Last modified: 02-Oct-2008
Last Reviewed: 04-Mar-2003

Metadata author:
Upper Columbia Area Office, USDI Bureau of Reclamation
c/o REQUIRED: The person responsible for the metadata information.
GIS Specialist
US Bureau of Reclamation
Box 1749
1917 Marsh Road
Yakima, WA 98907-1794
USA

509-575-5848 (voice)
509-454-5611 (FAX)
spatialdata@pn.usbr.gov

Hours_of_Service: 0730-1600
Contact_Instructions:
Call or e-mail data requests to contacts provided. Additional contact information is available at <http://spatialdata.pn.usbr.gov>
 
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:
 
Generated by mp version 2.9.6 on Thu Oct 23 10:08:30 2008
 

Last Update: July 25, 2011 3:08 PM