T-1746; Sheet No 2, Topography of Rosario Strait, W T, Ship Harbor and Padilla Bay, 1886

Metadata:

Identification_Information
Data_Quality_Information
Spatial_Reference_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Puget Sound River History Project

Originator: Department of Earth & Space Sciences, University of Washington, Box 351310

Originator: Seattle, WA 98195

Publication_Date: 10/01/03

Title: T-1746; Sheet No 2, Topography of Rosario Strait, W T, Ship Harbor and Padilla Bay, 1886

Geospatial_Data_Presentation_Form: map

Abstract:

Georeferenced United States Coast & Geodetic Survey Topographic Sheet T-1746; Sheet No 2, Topography of Rosario Strait, W T, Ship Harbor and Padilla Bay, 1886; Scale: 1:10,000; Surveyor: J. J. Gilbert

Supplemental_Information: For a comprehensive historical and technical review of the production and interpretation of early Coast & Geodetic Survey T-sheets please refer to Shalowitz, A.L. 1964. Shore and Sea Boundaries, Volumes 2. U.S. Department of Commerce, U.S. Coast and Geodetic Survey, Washington, DC. This publication is available online at http://chartmaker.ncd.noaa.gov/hsd/shallow.htm

Time_Period_of_Content: 1886

Time_Period_Information: 1886

Single_Date/Time:

Calendar_Date: 1886

Currentness_Reference: 1886

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None planned

Keywords:

Theme:

Theme_Keyword: T-sheets

Theme_Keyword: Coastal Survey

Theme_Keyword: Land Cover

Theme_Keyword: Historical

Theme_Keyword: United States Coast and Geodetic Survey

Place:

Place_Keyword: Washington State

Place_Keyword: Puget Sound

Stratum:

Stratum_Keyword: Near Shore

Stratum_Keyword: Coast

Temporal:

Temporal_Keyword: 1886

Access_Constraints:

This georeferenced image may be freely downloaded and used. Please give credit to the Puget Sound River History Project, University of Washington.

http://riverhistory.ess.washington.edu

Use_Constraints:

This georeferenced image may be freely downloaded and used. Please give credit to the Puget Sound River History Project, University of Washington.

http://riverhistory.ess.washington.edu

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Brian Collins, Amir Sheikh

Contact_Organization:

Department of Earth and Space Sciences, University of Washington

Contact_Address:

Address_Type: mailing address

Address: Department of Earth and Space Sciences

Address: Box 351310

Address: University of Washington

City: Seattle

State_or_Province: WA

Postal_Code: 98195

Country: USA

Contact_Voice_Telephone: (206) 616-6584

Contact_Facsimile_Telephone: (206) 543-0489

Contact_Electronic_Mail_Address: bcollins@u.washington.edu

Contact_Electronic_Mail_Address: asheikh@u.washington.edu

Data_Quality_Information:

Positional_Accuracy:

Horizontal_Positional_Accuracy: 4 meters (using 2 reliable benchmarks)

To assess an independent check of the accuracy of the registration process, benchmarks located on the T-sheets were compared to published NGS benchmarks that were retraceable to the time of the surveyed T-sheet. (Published NGS benchmark information is located at http://www.ngs.noaa.gov/cgi-bin/datasheet.prl). Only benchmarks that could be established with a high degree of certainty that existed at the time of the original T-sheet survey and were not remounted were used in the final accuracy measurement. If no current benchmarks exist or if the benchmarks have been remounted in relation to the benchmarks on the T-sheet, hard points (areas that would expect little change since the original surveys) were used to give a general indicator of the T-sheet’s registration accuracy in lieu of a more rigorous method. Thus these hard point measurements must be viewed with some caution. It should be stressed that the accuracy assessment was to check the accuracy of the overall registration process, not necessarily the accuracy of the survey itself.

NOTE: Measured distances are rounded to the nearest meter. The hand-drawn representations of benchmarks on the T-sheets are often up to 10 meters in width. To assess an independent check of the accuracy of the registration process, the measured distance is from the NGS-published coordinates to the perceived middle of the benchmark depicted on the T-sheet. In addition, the overall shape of the benchmark symbol is sometimes obscured by other symbology on the T-sheet. Thus, there is a certain level of uncertainty introduced due to the ambiguous location of the benchmark on the T-sheet.

Horizontal_Positional_Accuracy_Report:

Three benchmarks were identified on the T-sheet that corresponded to benchmarks in the NGS datasheets and were monumented prior to the date of the t-sheet. However, TIDE RESET is not clearly visible on the t-sheet, so it can only be used as a hard point. Therefore, HAT SOUTHEAST RESET and OBRIEN RESET were the two benchmarks used for the error assessment, and together gave an average error distance of 2.6 meters.

	Station Name	PID	Date Mon/Obs	Current Survey Control NAD83		Distance From Tsheet*
	Station Name		Date Mon/Obs	Current Survey Control NAD83		Distance From Tsheet*
9	HAT SOUTHEAST RESET	TR1909	1886	122 32 42.38527	48 31 13.97850	4.366062
12	OBRIEN RESET	TR1914	1886	122 35 04.56996	48 31 56.70178	2.756385
14	TIDE RESET	TR1891	1886	122 36 00.58884	48 31 15.50330	14.279712

*Measured distance between T-sheet benchmark & NGS-published benchmark

Lineage:

Technician: Elizabeth Cassel Date: 11-11-03

Process_Step:

Process_Description: The georeferencing of T-sheets in the Puget Sound region was funded by the Puget Sound Nearshore Project (PSNERP) http://www.pugetsoundnearshore.org/

Scanned images were obtained from Information Manufacturing Corporation, 7000 Infantry Ridge Road, Suite 200, Manassas, VA 20109 Phone: (703) 393-6866

The methodology used to georeference the T-sheets was modified from the previous work of Jennifer Burke (NOAA) in the Lower Columbia and Daniels et al (2001). The georeferencing and error assessment process were carried out using Erdas Imagine 8.6 and ArcGIS 8.3. For additional information concerning the georeferencing method please refer to: http://rocky2.ess.washington.edu/riverhistory/tsheets.php

Datum Shift:

Most T-sheets do not have a current datum represented on them (i.e. NAD 27, NAD 83). Graticules (tics) marking Latitude and Longitude in the early local Puget Sound Datum (PSD) and a later update to North American Datum (NAD) projection are most often present. To calculate the X, Y shift from NAD to NAD 27, X and Y values were used from datum difference tables for survey stations around most of Puget Sound (Patton, 1999). An overall datum shift was determined for the area covered by the T-sheet by averaging the shift from a number of survey stations in or nearby that area represented on the T-sheet.

The following survey station was used to calculate the datum shift:

Deception, 1854

Registration:

For georeferencing, tics were used only surrounding areas that depicted nearshore features on the T-sheet. This was mainly done to hasten the overall process due to the magnitude of the scope of the project while maintaining the best control around areas of interest. The sheets were then rectified using a 1^st order polynomial transformation. Points that produced relatively high RMS values, as well as tic points that consistently fell outside of 4.5 meters (on a 1:10,000 scale T-sheet) of their projected UTM coordinates were omitted.

The following tic marks were used for georeferencing the initial resample:

	Longitude		Latitude
	deg	min	deg	min
1	122	36	48	33
2	122	35	48	33
3	122	34	48	33
4	122	33	48	33
5	122	32	48	33
6	122	31	48	33
7	122	30	48	33
8	122	29	48	33
9	122	38	48	32
10	122	37	48	32
11	122	36	48	32
12	122	35	48	32
13	122	34	48	32
14	122	33	48	32
15	122	32	48	32
16	122	31	48	32
17	122	30	48	32
18	122	29	48	32
19	122	38	48	31
20	122	37	48	31
21	122	36	48	31
22	122	35	48	31
23	122	34	48	31
24	122	33	48	31
25	122	32	48	31
26	122	31	48	31
27	122	30	48	31
28	122	29	48	31
29	122	38	48	30
30	122	37	48	30
31	122	36	48	30
32	122	35	48	30
33	122	34	48	30
34	122	33	48	30
35	122	32	48	30
36	122	29	48	30
37	122	36	48	29
38	122	35	48	29
39	122	34	48	29
40	122	33	48	29
41	122	32	48	29
42	122	29	48	29

Two resamples were performed on this data. The first resample gave RMS errors all below 0.003 and only one point had an error distance greater than 4.3 meters. That was point 26 which had an error distance of 5.4 meters. This point, along with a few others, were adjusted for the final resample.

Several factors that can introduce error into the registration process include:

The accuracy of the graticules and projection lines drawn on the map.

Non-uniform shrinkage of the original map due to age and storage conditions.

Distortion caused by the scanning process.

Loss of resolution and distortion due to image compression.

Ability of the technician to identify appropriate survey stations that correspond to the area of the T-sheet to compute the datum shift.

Ability of the technician to identify and locate appropriate tics on the T-sheet for the transformation.

The geometric transformation method employed.

References:

Daniels, R. C. and R.H. Huxford. 2001. An error assessment of vector data derived from scanned National Ocean Service topographic sheets. Journal of Coastal Research 17: 611 – 619.

Patton, R.S., 1999. Datum Differences: Atlantic, Gulf, and Pacific Coast of the United States. U.S. Department of Commerce, U.S. Coast and Geodetic Survey, Washington D.C. (Original publication: 1936)

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: Universal Transverse Mercator

Universal_Transverse_Mercator:

UTM_Zone_Number: 10

Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.999600

Longitude_of_Central_Meridian: -123.000000

Latitude_of_Projection_Origin: 0.000000

False_Easting: 500000.000000

False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: row and column

Coordinate_Representation:

Abscissa_Resolution: 3.000000

Ordinate_Resolution: 3.000000

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257222

Distribution_Information:

Resource_Description: Downloadable Data

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Metadata_Reference_Information:

Metadata_Date: 20020723

Metadata_Contact: