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RFQ_295-03-2014 Elevation LiDAR and aerial imagery QC Surveys
3/4/14 8:00 AM
STATE OF NORTH CAROLINA
REQUEST FOR QUALIFICATION RFQ #295-03-2014
NORTH CAROLINA GEODETIC SURVEY
RFQ #295-03-2014 Page 1 of 33
TITLE: Statewide elevation (LiDAR) and aerial imagery quality control surveys
ISSUING AGENCY: North Carolina Geodetic Survey (GTM-NCGS)
ISSUE DATE: March 3, 2014
ISSUING AGENCY: State of North Carolina
North Carolina Department of Public Safety
North Carolina Division of Emergency Management
North Carolina Geospatial and Technology Management Office
North Carolina Geodetic Survey (GTM-NCGS)
Sealed proposals subject to the conditions made a part hereof will be received until 2:00 p.m., March 26, 2014 for furnishing services described herein.
Submit proposals directly to the issuing agency, the North Carolina Geodetic Survey, using either:
The mailing address for U.S. Postal Service (USPS) submitted proposals
~ or ~
The building (shipping) address for private delivery (e.g. FedEx, DHL, or UPS) or hand-delivered submitted proposals:
Mailing address: Building (shipping) address:
Attn: Gary W. Thompson, PLS
NC Geodetic Survey/GTM/EM/NCDPS
4298 Mail Service Center
RALEIGH NC 27699-4298
Attn: Gary W. Thompson, PLS
NC Geodetic Survey/GTM/EM/NCDPS
Bowers Building/NC National Guard military complex
4105 Reedy Creek Rd
RALEIGH NC 27607
Note: Failure to write out the entire mailing or shipping address could result in your proposal being delivered to the wrong building.
The North Carolina Geodetic Survey (NCGS), which is administratively located in the North Carolina Department of Public Safety (NCDPS)/Division of Emergency Management (EM), intends to award multiple Qualifications-Based Selection (QBS) contracts to private surveying firms (henceforth referred to as the “Contractor”) for the purpose of to supporting the Statewide Elevation (LiDAR) Project by performing quality control (QC) surveys on the LiDAR elevation data and any aerial imagery collected to support the elevation project utilizing Global Navigation Satellite System (GNSS) and traditional survey methods.
The work for this RFQ would consist of performing horizontal and vertical QC survey projects
Download the entire RFQ by clicking here.
2014 GPS on Bench Marks Campaign
2/26/14 2:13 PM
NOAA 's National Geodetic Survey is conducting a 2014 GPS on Bench Marks Campaign during National Surveyors Week (March 16-22).
Please read more at : http://www.ngs.noaa.gov/heightmod/GPSonBM.shtml
If you would like to help, download this KMZ file to view benchmarks in North Carolina that may be candidates for upgrade: NC Benchmarks
RFQ #295-02-2014 Results
2/12/14 7:51 AM
Results of the RFQ review committee for RFQ #295-02-2014.
Aerial Imagery Quality Control Surveys
Frequently Asked Questions (FAQs) regarding NAD 83(NSRS2007)
1. Why is the readjustment important?
The National Geodetic Survey (NGS) readjusted 67,693 GPS survey control points in the U.S. to the nationwide CORS network to:
Geospatial Positioning Accuracy Standards Part 2: Standards for Geodetic Networks (FGDC-STD-007.2-1998)
2. What do the components "NAD 83", "NSRS", and "2007" mean in the name "NAD 83(NSRS2007)"?
NAD 83(NSRS2007) is the readjustment of the North American Datum of 1983 (NAD 83) that was completed in 2007 that adjusted 67,693 GPS control points in the U.S. National Spatial Reference System (NSRS) to the Nationwide Continuously Operating Reference Stations (CORS) network.
North American Datum of 1983:
2007: The year that the readjustment was completed.
3. What datums are involved in the readjustment?
The adjustment involves two different datums: NAD 83 and the International Terrestrial Reference Frame (ITRF). The origin of both datums is at the mass center of the Earth, including oceans and the atmosphere, but the definition of each datum's origin is different.
4. What is International Terrestrial Reference Frame (ITRF)?
The International Terrestrial Reference Frame (ITRF) is a realization by a set of coordinates and velocities of reference points on the Earth. ITRF positions are generally determined with an accuracy of a few centimeters or better, even over continental or global distances. At this level of accuracy, tectonic plate motion (continental drift) and other forms of crustal motion must be taken into account. The use of ITRF positional coordinates is appropriate for those applications demanding the highest accuracy obtainable.
5. Were the NAVD 88 (North American Vertical Datum of 1988) elevations adjusted as part of the NAD 83(NSRS2007) adjustment?
No, the NAVD 88 elevation was not adjusted as part of the NAD 83(NSRS2007) horizontal adjustment.
6. What is an ellipsoid height?
An ellipsoid height is the vertical distance from a point to the reference ellipsoid along a line normal (perpendicular) to the ellipsoid.
7. Were the ellipsoid height of each mark involved in NAD 83(NSRS2007) readjustment adjusted?
Yes, the ellipsoid height of each mark involved in the readjustment was adjusted.
8. What is the horizontal positional shift in the NC State Plane Coordinate System between: NAD 83/86, NAD 83/95, NAD 83/2001, and NAD 83(NSRS2007)?
At station SMITHPORT (EZ5525) in Johnston County, the differences range from 0.004 m to 0.330 m.
Note: The above table is an example for one (1) mark only. On a statewide scale, the differences between NAD 83/2001 and NAD 83(NSRS2007) can be seen on the following map:
9. How are coordinates produced for the new adjustment?
National Geodetic Survey (NGS) publishes coordinates in NAD 83(NSRS2007) and will later in both NAD 83(NSRS2007) and ITRF. NGS will use published transformation methods to transform each station's coordinates from the assumed stationary-based NAD83 datum to the dynamic, plate tectonic-based ITRF by adding a velocity vector component to the coordinates. Therefore, even a station on the stable North American plate will have a velocity vector component in its ITRF set of coordinates, because the North American plate moves in the global reference frame.
10. What are the overall goals of the new readjustment?
11. What is the difference between Local Accuracy and Network Accuracy?
Local accuracy of a control point
Network accuracy of a control point
• A value that represents the uncertainty of its coordinates with respect to the geodetic datum, which is best expressed by the Continuously Operating Reference Stations (CORS) network at the 95% confidence level
NOTE: Both Local and Network accuracy values at CORS sites are considered to be infinitesimal (approaching zero). These accuracies will be implemented with the National Readjustment.
12. What control was used for the NAD 83(NSRS2007) adjustment?
Control for the NAD 83(NSRS2007) adjustment was provided by the CORS in each state in NAD 83 (epoch 2002.0), except for the following states that are located over unstable tectonic plates: Alaska (AK), Arizona (AZ), California (CA), Nevada (NV), Oregon (OR), and Washington (WA).
NOTE: For future projects located in AZ, AK, CA, NV, OR, WA, HTDP will still be required to correct any velocities associated with the published control.
13. What is Horizontal Time Dependent Positioning (HTDP)?
Horizontal Time Dependent Positioning (HTDP): An NGS developed software package (www.ngs.noaa.gov/TOOLS/htdp/htdp.html) that enables users to predict horizontal displacements and/or horizontal velocities related to crustal motion in the United States and its territories. The software also enables users to update positional coordinates and/or geodetic observations to a user-specified date. HTDP supports these activities for coordinates in:
Thus, this software may be used to transform geodetic coordinates between any pair of these reference frames (NAD 83, ITRF, or WGS 84) in a manner that rigorously addresses differences among the definitions of their respective velocity fields.
14. The Online Positioning User Service (OPUS) provides horizontal positions in North Carolina in which datum?
The Online Positioning User Service (OPUS) provided horizontal position information in both NAD 83 (CORS 96) (EPOCH:2002) ≅ NAD 83(NSRS2007) in North Carolina and ITRF 00 (EPOCH: current date).
OPUS provides height information in two forms (please see the OPUS output on the next page)
FILE: ncbe326a.07o 000261349
1008 NOTE: Antenna offsets supplied by the user were zero.Coordinates
1008 returned will be for the antenna reference point (ARP).
1008 NGS OPUS SOLUTION REPORT
USER: firstname.lastname@example.org DATE: December 04, 2007RINEX FILE: ncbe326a.07o TIME: 03:48:15 UTC
SOFTWARE: page5 0612.06 master10.pl START: 2007/11/22 00:00:00 EPHEMERIS: igr14544.eph [rapid] STOP: 2007/11/22 04:59:00
NAV FILE: brdc3260.07n OBS USED: 12568 / 12986 : 97%
ANT NAME: TRM55971.00 NONE # FIXED AMB: 65 / 65 :100% ARP HEIGHT: 0.0 OVERALL RMS: 0.017(m)
REF FRAME: NAD_83(CORS96)(EPOCH:2002.0000) ITRF00(EPOCH:2007.8907)
X: 1209852.559(m) 0.016(m) 1209851.851(m) 0.016(m)
Y: -5106864.755(m) 0.013(m) -5106863.255(m) 0.013(m)
Z: 3612274.171(m) 0.007(m) 3612274.026(m) 0.007(m)
LAT: 34 43 8.50917 0.011(m) 34 43 8.53530 0.011(m)E LON: 283 19 41.00794 0.017(m) 283 19 40.99446 0.017(m)W LON: 76 40 18.99206 0.017(m) 76 40 19.00554 0.017(m)EL HGT: -27.844(m) 0.004(m) -29.261(m) 0.004(m)ORTHO HGT: 9.631(m) 0.025(m) [Geoid03 NAVD88]
UTM COORDINATES STATE PLANE COORDINATES
UTM (Zone 18) SPC (3200 NC )Northing (Y) [meters] 3843157.754 109995.829 Easting (X) [meters] 346905.135 822811.690 Convergence [degrees] -0.95244413 1.34368569 Point Scale 0.99988889 0.99991552 Combined Factor 0.99989326 0.99991989
US NATIONAL GRID DESIGNATOR: 18SUD4690543158(NAD 83)
BASE STATIONS USED PID DESIGNATION LATITUDE LONGITUDE DISTANCE(m)AM7011 CASL CASTLE HAYNE CORS ARP N342040.707 W0775231.382 118027.2 AJ2915 WASR WASHINGTON CORS ARP N353334.802 W0770331.543 99701.2 DI4788 NBR6 NEW BERN 6 CORS ARP N351029.898 W0770259.335 61236.6
NEAREST NGS PUBLISHED CONTROL POINT EA1896 PIVERS ISLAND N344309.338 W0764021.256
This position and the above vector components were computed without anyknowledge by the National Geodetic Survey regarding the equipment orfield operating procedures used.
15. What is metadata?
A metadata record of information, usually presented as an XML document, which captures the basic characteristics of a data or information resource. It represents the who, what, when, where, why and how of the data resource. Geospatial metadata are used to document geographic digital resources such as Geographic Information System (GIS) files, geospatial databases, and earth imagery. A geospatial metadata record includes the following:
16. Are NAD 83(CORS 96) Epoch 2002 and NAD 83(2007) the same?
NGS has adopted a realization of NAD 83 called NAD 83(NSRS2007) for the distribution of coordinates at ~ 70,000 passive geodetic control monuments. This realization approximates the more rigorously defined NAD 83(CORS 96) realization in which Continuous Operating Reference Station (CORS) coordinates are distributed. NAD 83(NSRS2007) was created by adjusting GPS data collected during various campaign-style geodetic surveys performed between the mid-1980s and 2005. For the 2007 adjustment, NAD 83(CORS 96) positional coordinates for ~700 CORS were held fixed (predominantly at the 2002.0 epoch for the stable North American plate, but 2007.0 epoch in Alaska and western CONUS) to obtain consistent positional coordinates for the ~70,000 passive marks. NAD 83(NSRS2007) positional coordinates will be consistent with corresponding NAD 83(CORS 96) positional coordinates to within the accuracy of the GPS data used in the adjustment and the accuracy of the corrections applied to these data for systematic errors, such as refraction.