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2001 Saint Paul Elevation Contours

This page last update: 03/10/2003
Metadata created using Minnesota Geographic Metadata Guidelines.


Metadata Summary

Originator City of Saint Paul, Minnesota
Abstract City of Saint Paul contour data set is a linear data set created from a November 2001 LIDAR airborne survey. The data set is in an AutoCad drawing file format with the line work as polylines. The drawings depict one foot contour lines generated from the LIDAR point data covering the area of the City of Saint Paul.
Browse Graphic View a sample of the data.
Time Period of Content Date 11/2001
Currentness Reference
Access Constraints none
Use Constraints By acceptance of this data, the user agrees to include a copy of this metadata record, including the liability disclaimer, whenever the user transmits or provides the GIS Data (or any portion of it) to another user.
Distributor Organization Saint Paul Pulbic Works
Ordering Instructions Contact the City of Saint Paul Mapping and Records for ordering information.
Online Linkage none available


Full metadata for
2001 Saint Paul Elevation Contours

Go to Section:
1. Identification Information
2. Data Quality Information
3. Spatial Data Organization Information
4. Spatial Reference Information
5. Entity and Attribute Information
6. Distribution Information
7. Metadata Reference Information

 
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Section 1 Identification Information
Originator City of Saint Paul, Minnesota
Title 2001 Saint Paul Elevation Contours
Abstract City of Saint Paul contour data set is a linear data set created from a November 2001 LIDAR airborne survey. The data set is in an AutoCad drawing file format with the line work as polylines. The drawings depict one foot contour lines generated from the LIDAR point data covering the area of the City of Saint Paul.
Purpose The purpose of the data set is to provide information for preliminary drainage, street, road and site development plans.
Time Period of Content Date 11/2001
Currentness Reference
Progress Complete
Maintenance and Update Frequency
Spatial Extent of Data The geographic limits of the City of Saint Paul, Minnesota
Bounding Coordinates -93.21
-93.11
44.99
44.89
Place Keywords Saint Paul, Ramsey County, Twin Cities
Theme Keywords contour, elevation, topographic, topo
Theme Keyword Thesaurus
Access Constraints none
Use Constraints By acceptance of this data, the user agrees to include a copy of this metadata record, including the liability disclaimer, whenever the user transmits or provides the GIS Data (or any portion of it) to another user.
Contact Person Information Jeffrey L. Grosso, Chief Surveyor
City of Saint Paul Public Works
25 West Fourth Street - 900 City Hall Annex
Saint Paul, Minnesota 55102
Phone: 651-266-6075
FAX: 651-292-6315
E-mail: jeff.grosso@ci.stpaul.mn.us
Browse Graphic View a sample of the data at:   http://www.datafinder.org/metadata/SORRY_NO_SAMPLE_GRAPHIC_YET.htm
Browse Graphic File Description
Associated Data Sets Saint Paul DEM

 
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Section 2 Data Quality Information
Attribute Accuracy The elevation attribute accuracy is based on a November, 2001 LIDAR airborne survey. The point data collected in this manner was tested to meet VMAS mapping accuracy at the 90% confidence level of 0.53 feet when compared against the final delivered DEM.
Logical Consistency
Completeness The geographic area of the City of Saint Paul, Minnesota is covered by the data set.
Horizontal Positional Accuracy The vendor for this project (Waggoner Engineering, Inc.) states in their flight planning documentation that the horizontal accuracy of each point is 1.5 feet.
Vertical Positional Accuracy The verticle accuracy is based on the independent collection of 199 ground surveyd points distributed throughout the project. The comparison for the surveyed determined elevation at each coordinate point and the DEM elevation for the same coordinate, the VMAS mapping accuracy at a 90% confidence level is 0.53 feet. The NSSDA mapping accuracy at a 95% confidence level is 0.63 feet.
Lineage The source of the DEM point data used to create the one foot contours in this data set are from a LIDAR airborne survey done by Waggoner Engineering, Inc. (WEI) in November of 2001. WEI utilized the Optech 1210 system for this project. The Optech system has been modified by the manufacturer to include extended altitude performance, record simultaneous first and last pulse data, store raw IMU data and enchanced transmitter and receiver optics. The system's Class IV laser has the capability to fire the laser from 100HZ to 5KHZ and an operational scan rate of 28 HZ at a scan angle of plus or minus 20 degrees. The airborne system also uses a LR86 IMU and a dual frequency Novatel DL GPS receiver, both collection at 1HZ. The L1 and L2 frequencies are collected wtih a L1/L2 geodetic kinematic atenna mounted to the top of the aircraft.

The ground control system consisted of two Novatel DL dual frequency GPS receivers, one placed on the ground control station Holman and one placed on the ground control station Base Pt B. The ground system used geodetic L1/L2 antennas with choke ring.

A calibration of the LIDAR system was conducted in December, 2001 in Saint Paul. The calibration site was a large commercial building and the Lafayette Bridge (T.H. 52) over the Mississippi River. The calibration yielded results of deviations of 8.5 centimeters for pitch, 12.0 centimeters for roll and 12.4 centimeters for heading. The precision of the LIDAR instrument was also tested by this calibration. A flat control area of ten feet square was used to compare four flight passes over the area. The flight lines were approximately perpendicular to each other and in opposite directions. The results of the precision analysis showed that no more than 7 centimeters of ranging deviation existed between the four passes.

Continuity between opposite flight line data sets is frequently tested for shifts and divergence. Orhtorectified photographs and profile analysis techniques are used to determine flat surfaces with no vegetation for this analysis. The project contained minimal or no shifts between flight lines from the same survey date or between flight lines from different survey days.

Systematic errors are tested from each flight day using independent ground survey control. The ground survey control for the LIDAR airborne survey consisted of field observations for 19 cross sections taking at locations recommended by WEI. The cross sections were approximately 900 long with the observations spaced at 50 foot intervals. One of the cross sections was taken on the slope of the right bank of the Mississippi River. An analysis of the 418 ground points yielded an RMSEz of 0.38 feet. This means the airborne survey data had a VMAS mapping accuracy at the 90% confidence level of 0.62 feet and a NSSDA mapping accuracy at the 95% confidence level of 0.74 feet.

The ground survey cross sections may have been used to adjust the elevation model, therefore the City of Saint Paul tested the delivered data by using 199 well distributed ground surveyed elevation points. The analysis of these points yielded a RMSEz of 0.32 feet. Therefore the VMAS mapping accuracy at the 90% confidence level is 0.53 feet and the NSSDA mapping accuracy at the 95% confidence level is 0.63 feet.

The poject was orignally processed in UTM Zone 15 (1996) coordinates and the NGVD 88 elevation datum. In order to transform to Ramsey County (1986) coordinate system six control points were chosen to determine the horizontal shift between the two systems. The control points were evenly distributed around the project area. The average displacement between the two systems was calculated and once applied yielded a maximum difference of 2 centimeters. The vertical shift between the NGVD and the city of Saint Paul datum was determined to be -694.26 feet. This factor was calculated from an analysis of 82 bench marks distributed throughout the city that had elevatons in both sytems.

Users need to be aware of the potential for errors in about one percent of the collected points, based on a comparison between the DEM and a photogrametric elevation model that covered about three quarters of a square mile. Users need to check the points in their project area for erroneous points.
Source Scale Denominator
 
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Section 3 Spatial Data Organization Information
Native Data Set Environment AutoCAD version 12.0 drawing files
Geographic Reference for Tabular Data
Spatial Object Type
Vendor Specific Object Types
Tiling Scheme Section, Township, Range
 
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Section 4 Spatial Reference Information
Horizontal Coordinate Scheme County Coordinates
Ellipsoid GRS80
Horizontal Datum NAD83
Horizontal Units Feet
Distance Resolution
Altitude Datum City of Saint Paul datum.
Altitude Units Feet
Map Projection Name Lambert Conformal Conic
Map Projection Parameters See the Minnesota Department of Transportation web site a http://rocky.dot.state.mn.us/geod/projections.htm for the parameters of the Ramsey County coordinate system.
 
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Section 5 Entity and Attribute Information
Entity and Attribute Overview
Elevation 
Entity and Attribute Detailed Citation
 
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Section 6 Distribution Information
Publisher City of Saint Paul, Minnesota
Publication Date Unpublished material
Contact Person Information Richard Person
Mapping and Records
Saint Paul Pulbic Works
25 West Fourth Street - 800 City Hall Annex
Saint Paul, Minnesota 55102
Phone: 651-266-6122
FAX: 651-298-4559
E-mail: rick.person@ci.stpaul.mn.us
Distributor's Data Set Identifier 1 foot contours
Distribution Liability NOTICE: The Geographic Information System (GIS) Data to which this notice is attached are made available pursuant to the Minnesota Government Data Practices Act (Minnesota Statutes Chapter 13). THE GIS DATA ARE PROVIDED TO YOU AS IS AND WITHOUT ANY WARRANTY AS TO THEIR PERFORMANCE, MERCHANTABLILITY, OR FITNESS FOR ANY PARTICULAR PURPOSE. The GIS Data were developed by the City of Saint Paul Public Works for its own internal business purposes. The City of Saint Paul Public Works does not represent or warrant that the GIS Data or the data documentation are error-free, complete, current or accurate. You are reponsible for any consequences resulting from your use of the GIS Data or your reliance on the GIS Data. You should consult the data documentation for this particular GIS Data to determine the limitations of the GIS Data and the precision with which the GIS Data may depict distance, direction, location, or other geographic features. If you transmit or provide the GIS Data ( or any portion of it) to another user, the GIS Data must inculde a copy of this disclaimer.
Transfer Format Name AutoCad drawing file
Transfer Format Version Number AutoCad version 12
Transfer Size AutoCad drawing file sizes of 1MB to 222MB.
Ordering Instructions Contact the City of Saint Paul Mapping and Records for ordering information.
Online Linkage none available
 
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Section 7 Metadata Reference Information
Metadata Date 03/10/2003
Contact Person Information Jeffrey L. Grosso, Chief Surveyor
Saint Paul Public Works
25 West Fourth Street - 900 City Hall Annex
Saint Paul, Minnesota 55102
Phone: 651-266-6075
FAX: 651-292-6315
E-mail: jeff.grosso@ci.stpaul.mn.us
Metadata Standard Name Minnesota Geographic Metadata Guidelines
Metadata Standard Version 1.2
Metadata Standard Online Linkage http://www.lmic.state.mn.us/gc/stds/metadata.htm




This page last updated: 03/10/2003