T-1955; Washington Sound, North End of Lopez Island, Wash. Terr., 1889

Metadata:

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-1955; Washington Sound, North End of Lopez Island, Wash. Terr., 1889

Geospatial_Data_Presentation_Form: map

Abstract:

Georeferenced United States Coast & Geodetic Survey Topographic Sheet T-1955; Washington Sound, North End of Lopez Island, Wash. Terr., 1889; 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:  1889

Time_Period_Information:  1889

Single_Date/Time:

Calendar_Date: 1889

Currentness_Reference: 1889

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: 1889

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: 4.8 meters (using 5 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 fifteen benchmarks clearly marked on this 1:10,000 scale t-sheet.  However only five pertain to NGS records and were used for the error assessment.

           

Station Name

PID

Date Mon/Obs

Longitude

Latitude

Distance***

FLAT POINT, 1889

TR2120

1889

122 55 10.75920

48 33 03.56898

4.494881

KENT RESET

TR2088

1889

122 55 18.76621

48 32 30.01492

4.592331

RED RESET

TR2093

1889

122 56 01.81899

48 30 50.45164

7.513125

ROCKSLIDE, 1889

TR2111

1889

122 53 28.91366

48 34 03.61976

3.522015

UPRIGHT RESET

TR2122

1889

122 53 03.72690

48 34 21.73176

3.806002

 

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

           

Lineage:

Technician: Soleil Kelley Date:  10.15.2003

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:

 

Iceberg, 1854

San Juan, 1867

Bellevue, 1854

Obstruction, 1854

Blakely 1, 1854

James North, 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 1st 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

54

48

35

2

122

53

48

35

3

122

52

48

35

4

122

55

48

34

5

122

54

48

34

6

122

53

48

34

7

122

52

48

34

8

122

51

48

34

9

122

56

48

33

10

122

55

48

33

11

122

54

48

33

12

122

53

48

33

13

122

52

48

33

14

122

51

48

33

15

122

56

48

32

16

122

55

48

32

17

122

54

48

32

18

122

53

48

32

19

122

52

48

32

20

122

51

48

32

21

122

57

48

31

22

122

56

48

31

23

122

55

48

31

24

122

54

48

31

25

122

53

48

31

26

122

52

48

31

27

122

51

48

31

28

122

57

48

30

29

122

56

48

30

30

122

55

48

30

31

122

54

48

30

32

122

53

48

30

33

122

52

48

30

 

Three resamples were performed on this data.  The first had an average error distance of 6 meters and an RMS of 0.0888.  Several points (1, 3, 8, 28, and 32) had errors greater than 10 meters and/or were not needed to triangulate the shoreline, so were removed for the second resample (RMS of 0.0709).  Upon resampling, the error of roughly half of the tics increased significantly while the error in the other half did not reduce significantly.  Only the points 3, 28, and 32 (those with highest error) were removed for the third resample.  The overall error reduced.  Resample # 3 was chosen as the “finalresample” as it has a lower RMS and greater positional accuracy at or near the shoreline. 

 

The image was then reprojected to UTM ZONE 10N NAD83/HARN using a rigorous transformation.

 

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

 

 

 

 

 

 

 

 

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:

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

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time