T-1871; Gulf of Georgia, from Village Point to Base of Sandy Point, Wash. Terr. 1888

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-1871; Gulf of Georgia, from Village Point to Base of Sandy Point, Wash. Ter. 1888

Geospatial_Data_Presentation_Form: map

Abstract:

Georeferenced United States Coast & Geodetic Survey Topographic Sheet T-1871; Gulf of Georgia, from Village Point to Base of Sandy Point, Wash. Ter. 1888; 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:  1888

Time_Period_Information:  1888

Single_Date/Time:

Calendar_Date: 1888

Currentness_Reference: 1888

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: 1888

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: 7.7 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:

NGS datasheets were sought for seven benchmarks clearly marked on this 1:10,000 scale t-sheet.  However, only three pertain to NGS records and were used. Benchmarks SWAMP, SANDY POINT, LUMMI NE, and VILLAGE POINT were not used (e.g. Sandy Point = remount)

  

  BENCHMARK NAME       PID           DATE          LONG         LAT        Measured distance (meters) b/n T-sheet benchmark & NGS-published benchmark     

                                                                        MON/OBS

FERN

TR1982

1888

122 43 19.59791

48 43 51.89101

8.336958

MIDGELY

TR1988

1888

122 42 55.55243

48 44 55.25603

6.976617

GORDON (WITNESS)**

TR1997

1956

122 40 20.79083

48 43 57.51292

11.310995

           

** Note: The location of benchmark WITNESS, denoted on T-sheet 1871, is now occupied by benchmark GORDON (1956).  The NGS Datasheet makes no mention of the older benchmark; therefore GORDON is not used in the total error assessment, as it is likely a remount of WITNESS. 

 

Lineage:

Technician: Soleil Kelley. Date:  10.03.2003

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 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:

           

River 2, 1859

Lummi South Base 1858

Bend 2, 1859

Lummi 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

42

48

50

2

122

42

48

49

3

122

41

48

49

4

122

40

48

49

5

122

39

48

49

6

122

38

48

49

7

122

43

48

48

8

122

42

48

48

9

122

41

48

48

10

122

40

48

48

11

122

39

48

48

12

122

38

48

48

13

122

37

48

48

14

122

43

48

47

15

122

42

48

47

16

122

41

48

47

17

122

40

48

47

18

122

39

48

47

19

122

38

48

47

20

122

43

48

46

21

122

42

48

46

22

122

41

48

46

23

122

40

48

46

24

122

39

48

46

25

122

38

48

46

26

122

44

48

45

27

122

43

48

45

28

122

42

48

45

29

122

41

48

45

30

122

40

48

45

31

122

39

48

45

32

122

44

48

44

33

122

43

48

44

34

122

42

48

44

35

122

41

48

44

36

122

40

48

44

37

122

39

48

44

38

122

43

48

43

39

122

42

48

43

 

Only two resamples were performed on this data.  The first resample had low error distance in general, with the exception of points 1 and 7, which had errors of 12 and 6 meters respectively (RMS values of 0.005 and 0.004).  These points were removed, and all RMS errors became <0.003.  The overall RMS is 0.0015.

 

 

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:

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:

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