T-1671; Puget Sound, from Pt. Defiance to Ketron Isd., Washington Territory, 1877-78

Metadata:

Identification_Information
Data_Quality_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-1671; Puget Sound, from Pt. Defiance to Ketron Isd., Washington Territory, 1877-78

Geospatial_Data_Presentation_Form: map

Abstract:

Georeferenced United States Coast & Geodetic Survey Topographic Sheet T-1671; Puget Sound, from Pt. Defiance to Ketron Isd., Washington Territory, 1877-78; Scale: 1:20,000; Surveyor: Eugene Ellicott

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: 1877-78

Time_Period_Information: 1877-78

Single_Date/Time:

Calendar_Date: 1877-78

Currentness_Reference: 1877-78

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: 1877-78

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 meters (using 2 reliable benchmarks)

The Titus Bay area of the T-sheet appears to have significant registration error in relation to the rest of the T-sheet. It is assumed that this is due to original survey, cartographic, or drafting error, and not due to the georeferencing process, since the majority of the T-sheet matches the drg and the nearby T-sheets, and the benchmark error assessment is so low.

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:

Seven possible benchmarks were identified on the T-sheet and in the NGS datasheets, but only two of these actually corresponded with benchmarks on the T-sheet and were monumented prior to T-sheet production. So these two benchmarks were used for the error assessment.

	Station Name	PID	Date Mon/Obs	Current Survey Control NAD83		Measured distance between T-sheet benchmark & NGS-published benchmark
	Station Name	PID	Date Mon/Obs	Current Survey Control NAD83
				Longitude	Latitude
1	GOLDSBOROUGH 1857	SY3039	1857	122 37 01.53763	47 13 28.73933	8.569797
2	BOULDER	SY3118	1877	122 41 27.69499	47 11 34.70950	5.382353

Lineage:

Technician: Elizabeth Cassel Date: 10-16-03

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:

Wash 2, 1921

Smelt, 1905

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	35	47	21
2	122	34	47	21
3	122	33	47	21
4	122	36	47	20
5	122	35	47	20
6	122	34	47	20
7	122	33	47	20
8	122	32	47	20
9	122	31	47	20
10	122	34	47	19
11	122	33	47	19
12	122	32	47	19
13	122	31	47	19
14	122	30	47	19
15	122	37	47	18
16	122	36	47	18
17	122	35	47	18
18	122	34	47	18
19	122	33	47	18
20	122	32	47	18
21	122	31	47	18
22	122	30	47	18
23	122	29	47	18
24	122	40	47	17
25	122	39	47	17
26	122	38	47	17
27	122	37	47	17
28	122	36	47	17
29	122	35	47	17
30	122	34	47	17
31	122	33	47	17
32	122	32	47	17
33	122	31	47	17
34	122	30	47	17
35	122	29	47	17
36	122	40	47	16
37	122	39	47	16
38	122	38	47	16
39	122	37	47	16
40	122	36	47	16
41	122	35	47	16
42	122	34	47	16
43	122	33	47	16
44	122	32	47	16
45	122	40	47	15
46	122	39	47	15
47	122	38	47	15
48	122	37	47	15
49	122	36	47	15
50	122	35	47	15
51	122	34	47	15
52	122	33	47	15
53	122	32	47	15
54	122	43	47	14
55	122	42	47	14
56	122	41	47	14
57	122	40	47	14
58	122	39	47	14
59	122	38	47	14
60	122	37	47	14
61	122	36	47	14
62	122	35	47	14
63	122	34	47	14
64	122	33	47	14
65	122	44	47	13
66	122	43	47	13
67	122	42	47	13
68	122	41	47	13
69	122	40	47	13
70	122	39	47	13
71	122	38	47	13
72	122	37	47	13
73	122	36	47	13
74	122	35	47	13
75	122	34	47	13
76	122	45	47	12
77	122	44	47	12
78	122	43	47	12
79	122	42	47	12
80	122	41	47	12
81	122	40	47	12
82	122	39	47	12
83	122	38	47	12
84	122	37	47	12
85	122	36	47	12
86	122	35	47	12
87	122	34	47	12
88	122	45	47	11
89	122	44	47	11
90	122	43	47	11
91	122	42	47	11
92	122	41	47	11
93	122	40	47	11
94	122	39	47	11
95	122	38	47	11
96	122	37	47	11
97	122	36	47	11
98	122	35	47	11
99	122	34	47	11
100	122	41	47	10
101	122	40	47	10
102	122	39	47	10
103	122	38	47	10
104	122	37	47	10
105	122	36	47	10
106	122	35	47	10
107	122	41	47	9
108	122	40	47	9
109	122	39	47	9
110	122	38	47	9
111	122	37	47	9
112	122	39	47	8
113	122	38	47	8
114	122	37	47	8

Four different resamples were performed on this data. The RMS errors were ranged from 0 to 0.005 after the first resample, and a few points had errors up to 25 meters. Combinations of the points 9, 14, 23, 35, 76, 88, 90, 97, 106, and 108 were removed for the second and third resample. For the final resample, points 23, 35, 76 and 88 were removed, which resulted in the lowest overall RMS errors and error distances, as well as the best match to the drgs.

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: