T-1390b-1; D'Wamish Bay, Wash. Ter., 1874

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-1390b-1; D'Wamish Bay, Wash. Ter., 1874

Geospatial_Data_Presentation_Form: map

Abstract:

Georeferenced United States Coast & Geodetic Survey Topographic Sheet T-1390b-1; D'Wamish Bay, Wash. Ter., 1874; Scale: 1:10,000; Surveyor: Jas. S. Lawson

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:  1874

Time_Period_Information:  1874

Single_Date/Time:

Calendar_Date: 1874

Currentness_Reference: 1874

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: 1874

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: no traceable 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:

Four possible benchmarks were located within the map extent that might be used for horizontal verification.  These points were set after this t-sheet was made but their written descriptions refer to topological features that could be generally relocated.  None of these points are definite enough to use for a veritable accuracy assessment.

 

     Benchmark        PID       LONG     LAT        Measured distance between T-sheet benchmark & NGS-published benchmark         

 

Station Name

PID

Current Survey Control NAD83

Distance From Tsheet, using NEAR

Year Monumented

 Long

 Lat

FOUR MILE LIGHT

SY4764

122 24 48.55430

47 38 20.44760

 

1921

FOURMILE ROCK LIGHT

SY4766

122 24 48.55186

47 38 20.44457

 

1963

WEST POINT 1921

SY4798

122 26 09.10940

47 39 43.05447

 

1921

WEST PT LIGHTHOUSE

SY4779

122 26 08.52927

47 39 43.08084

 

1921

 

Lineage:

Technician: Joanna Marsolek  Date:  8-26-03

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 stations were used to calculate the datum shift:

 

Alki (S.W.B.), 1921

West Point, 1921

 

            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

26

47

40

2

122

25

47

40

3

122

24

47

40

4

122

23

47

40

5

122

22

47

40

6

122

21

47

40

7

122

26

47

39

8

122

25

47

39

9

122

24

47

39

10

122

23

47

39

11

122

22

47

39

12

122

21

47

39

13

122

25

47

38

14

122

24

47

38

15

122

23

47

38

16

122

22

47

38

17

122

21

47

38

18

122

23

47

37

19

122

22

47

37

20

122

21

47

37

21

122

20

47

37

22

122

24

47

36

23

122

23

47

36

24

122

22

47

36

25

122

21

47

36

26

122

25

47

35

27

122

24

47

35

28

122

23

47

35

29

122

22

47

35

30

122

25

47

34

31

122

24

47

34

 

Two resamples were performed with variations on this data.  All of the points had low RMS values throughout the resampling with points 7 and 21 having the greatest values at 0.004.  Removing these points did not significantly effect the RMS values, and while the error distances decreased for some points they increased for others.  The first resample was decided sufficient.

 

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: 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:

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