T-2192; Washington Sound, Orcas and Waldron Islands, Wash. Ter. 1894

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-2192; Washington Sound, Orcas and Waldron Islands, Wash. Ter. 1894

Geospatial_Data_Presentation_Form: map

Abstract:

Georeferenced United States Coast & Geodetic Survey Topographic Sheet T-2192; Washington Sound, Orcas and Waldron Islands, Wash. Ter. 1894; 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: 1894

Time_Period_Information: 1894

Single_Date/Time:

Calendar_Date: 1894

Currentness_Reference: 1894

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: 1894

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: 5.3 meters (using 8 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 twelve benchmarks clearly marked on this 1:10,000 scale t-sheet. However, only ten pertain to NGS records and were used. Benchmarks HAMMOND and CATERPILLAR had no relevant datasheets.

Station Name	PID	Date Mon/Obs	Longitude	Latitude	Measured distance (m) between T-sheet benchmark & NGS-published benchmark
BARE ISLAND 2 1894	TR2196	1894	123 00 51.52361	48 43 46.96930	4.086340535
DOUGHTY 4	TR2143	1940	122 56 58.90415	48 42 42.76940	8.088240498
DRY RESET	TR2184	1942	123 02 25.38530	48 43 02.10923	3.913532173
FREEMAN 1894	TR2145	1894	122 57 06.55423	48 41 57.16030	7.190704642
MIDDLETON 1894	TR2191	1894	123 04 16.90369	48 41 58.20402	8.685079849
ROUND RESET	TR2185	1894	123 00 16.56899	48 42 14.92820	5.39139532
SKIPJACK RESET	TR2183	1894	123 02 20.73970	48 43 57.40454	4.698007277
SLANT RESET	TR2139	1894	122 59 03.90344	48 40 28.99248	3.06524127
SMALL RESET	TR2199	1894	123 01 15.42667	48 40 54.32937	4.535057776
WALDRON 1894	TR2186	1894	123 02 36.07514	48 40 35.22666	4.485895751

Note: DOUGHTY 4 and DRY RESET have been Remounted at location of existing benchmarks and are not used in the horizontal positional accuracy calculation of 5.3 meters.

Lineage:

Technician: Soleil Kelley Date: 10.6.2003

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:

Dry, 1894

Bare Island, 1894

Hammond, 1853

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	123	3	48	44
2	123	2	48	44
3	123	1	48	44
4	123	0	48	44
5	123	4	48	43
6	123	3	48	43
7	123	2	48	43
8	123	1	48	43
9	123	0	48	43
10	122	57	48	43
11	122	56	48	43
12	122	55	48	43
13	123	5	48	42
14	123	4	48	42
15	123	3	48	42
16	123	2	48	42
17	123	1	48	42
18	123	0	48	42
19	122	59	48	42
20	122	58	48	42
21	122	57	48	42
22	122	56	48	42
23	122	55	48	42
24	123	4	48	41
25	123	3	48	41
26	123	2	48	41
27	123	1	48	41
28	123	0	48	41
29	122	59	48	41
30	122	58	48	41
31	122	57	48	41
32	122	56	48	41
33	122	55	48	41
34	123	0	48	40
35	122	59	48	40
36	122	58	48	40
37	122	57	48	40
38	122	56	48	40

Three resamples were performed on this data. The first resample had error distance ranging from 0.5 to 12 meters with an overall RMS of 0.0748. Points 4,12, 33, and 38 had errors of 7, 12, 7, 9 meters respectively, and were removed for the second resample (subsequent RMS of 0.0449). Overall error distances decreased, but points 5, 31, and 35 still had high RMS values so they were removed for the final resample. The overall RMS error reduced to 0.0414.

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: