T-2230; Washington Sound, Wash. Ter., Orcas Shaw and San Juan Islands, 1895

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-2230; Washington Sound, Wash. Ter., Orcas Shaw and San Juan Islands, 1895

Geospatial_Data_Presentation_Form: map

Abstract:

Georeferenced United States Coast & Geodetic Survey Topographic Sheet T-2230; Washington Sound, Wash. Ter., Orcas Shaw and San Juan Islands, 1895; 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: 1895

Time_Period_Information: 1895

Single_Date/Time:

Calendar_Date: 1895

Currentness_Reference: 1895

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: 1895

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: 7.6 meters (using 26 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:

NGS datasheets were sought for forty-one clearly labeled benchmarks on this 1:10,000 scale T-sheet. Datasheets are available for 36 of these records, however only 26 were used in the error assessment. The 10 omitted lie outside the detailed study area or are difficult to locate accurately on the T-sheet.

	Benchmark Name	PID	Date Mon/Obs	Longitude		Latitude	Distance***
1	BAY RESET	TR2106	1889	122 55 19.31994	48 33 44.29327		5.545844
2	BERRY RESET	TR2215	1894	123 00 58.29701	48 32 26.72330		15.293469
3	BROKEN RESET	TR2108	1894	122 58 00.08991	48 35 42.76454		2.870805
4	BROWN	TR2235	1940	123 00 05.24161	48 32 19.91593		2.587234
5	CANOE	TR2074	1889	122 55 30.74227	48 33 16.91572		8.187093
6	COVE RESET	TR2089	1889	122 56 15.83414	48 33 28.92712		3.448091
7	CREST 1894	TR2114	1894	122 59 42.28676	48 32 04.10736		9.075363
8	DANGER RESET	TR2099	1889	122 58 16.50943	48 31 15.88124		5.289583
9	FRIDAY RESET	TR2219	1894	123 00 29.33972	48 32 47.41878		11.837825
10	GEORGE 1954	TR2076	1954	122 58 55.27348	48 33 40.68622		14.398436
11	LAST 1894	TR2113	1894	122 59 47.63482	48 31 46.37879		11.153495
12	NICHE 1894	TR2220	1894	123 00 38.21357	48 32 03.66032		14.815489
13	NUBBINS RESET	TR2104	1894	122 56 45.82066	48 35 13.56006		9.354012
14	PARKS BAY 1954	TR2095	1954	122 59 05.33863	48 33 57.26160		3.147909
15	PINE RESET	TR2083	1889	122 54 53.95296	48 35 29.63112		4.90564
16	POINT 1894	TR2096	1894	122 55 17.72925	48 35 13.28045		9.217339
17	POST RESET	TR2086	1894	122 56 49.49265	48 35 49.71466		4.214678
18	RAG 1894	TR2085	1894	122 57 12.00	48 36 10.66415		7.073217
19	SHAW NE 1889	TR2077	1889	122 54 16.46944	48 34 54.23087		2.690131
20	SHAW SE RESET	TR2098	1889	122 56 38.73781	48 32 53.30746		1.196838
21	SLOPE 2	TR2241	1940	123 00 21.01730	48 33 07.16046		5.225444
22	SNAKE 1894	TR2082	1894	122 55 39.30	48 35 28.03601		8.372429
23	STRONG RESET	TR2067	1894	122 58 41.60939	48 33 05.71859		9.522718
24	SWIFT RESET	TR2101	1894	122 59 16.11069	48 33 31.48723		8.745384
25	TURN 2	TR2112	1940	122 58 14.70191	48 32 08.45473		8.925101
26	TURN ROCK LIGHT 1940	TR2073	1940	122 57 52.53078	48 32 06.29636		12.44344

***Measured distance (m) between T-sheet benchmark & NGS-published benchmark

Lineage:

Technician: Soleil Kelley Date: 10.8.2003

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 University of Washington Libraries at http://www.wsulibs.wsu.edu/holland/masc/sanjuanindex.html

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 stations were used to calculate the datum shift:

San Juan, 1867

Bellevue, 1854

Orcas, 1853

Lawrence, 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	57	48	37
2	122	56	48	37
3	122	55	48	37
4	122	58	48	36
5	122	57	48	36
6	122	56	48	36
7	122	55	48	36
8	122	54	48	36
9	122	53	48	36
10	122	59	48	35
11	122	58	48	35
12	122	57	48	35
13	122	56	48	35
14	122	55	48	35
15	122	54	48	35
16	122	52	48	35
17	123	0	48	34
18	122	59	48	34
19	122	58	48	34
20	122	57	48	34
21	122	56	48	34
22	122	55	48	34
23	122	54	48	34
24	122	53	48	34
25	123	1	48	33
26	123	0	48	33
27	122	59	48	33
28	122	58	48	33
29	122	57	48	33
30	122	56	48	33
31	122	55	48	33
32	123	1	48	32
33	123	0	48	32
34	122	59	48	32
35	122	58	48	32
36	122	57	48	32
37	122	56	48	32
38	123	0	48	31
39	122	59	48	31
40	122	58	48	31
41	122	57	48	31
42	122	58	48	30

Three resamples were performed on this data. The first resample had error distance ranging from 0.5 to 17 meters with an overall RMS of 0.0672. Points 2, 3, 10, 32, 38, and 41 had errors greater than 5 meters and/or did not triangulate areas of great detail/importance. They were removed for the second resample (subsequent RMS of 0.0498). Overall error distances decreased, but points 11, 33, 25, 28, 29, and 4 still had high RMS values so they were removed for the final resample. The overall RMS error reduced to 0.0418.

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: 2.000000

Ordinate_Resolution: 2.000000

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1927

Ellipsoid_Name: Clarke 1866

Semi-major_Axis: 6378206.400000

Denominator_of_Flattening_Ratio: 294.978698

Distribution_Information:

Resource_Description: Downloadable Data

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Transfer_Size: 24.630

Metadata_Reference_Information:

Metadata_Date: 20020723

Metadata_Contact: