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Thursday July 30, 2015

A series of short video tutorials are now available to help navigate the most-recently developed NC Geodetic Database. The videos can be accessed by clicking the link below:

NCGS 2 Navigating
NCGS 3 View Details
NCGS 4 Station Recovery
NCGS 5 Export Data

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Monday, June 1, 2015

Severe solar storm serves as a reminder to always check the space weather forecast before doing any
GNSS surveying, precision agriculture, or GNSS-guided earthmoving work
 
The sun had a coronal mass ejection (CME) on June 18, 19, and 21 that we are experiencing as a series of geomagnetic storms.  The NOAA Space Weather Prediction Center (SWPC) announced on Monday, June 22, that "the geomagnetic storm began as forecasted and quickly ramped up to severe (G4) levels."  
 
On June 23, SWPC predicted the following over the June 23, 24, & 25 period:
The geomagnetic field is expected to remain agitated with G1-G2 (Minor - Moderate) possible early on day one (23 Jun) in continued response to the 21 Jun CME.  Conditions are expected to continue to gradually taper off below G1 (Minor) over the next 12-18 hours back to quiet to active conditions.  The 21 Jun CME is expected to arrive late on day two (24 Jun) to early on day three (25 Jun).  The CME will likely enhance geomagnetic conditions to G1-G2 (Minor-Moderate) levels with the possibility for stronger conditions on day three (25 Jun).
 
On June 24, SWPC predicted the following over the June 24, 25, & 26 period:
G1 (Minor) geomagnetic storms are expected with waning effects from past CME.  With the onset of the new CME, storming conditions up to G3 (Strong) are likely.
 
It is important to note that the SWPC reported the following in its June 23rd 3-Day Forecast, “No radio blackouts were observed over the past 24 hours.”  Furthermore, SWPC predicted a 75% chance of minor-moderate (R1-R2) radio blackout levels for June 24, 25, and 26 and a 20% chance of a strong (R3 or greater) radio blackout over the 3-day period.  SWPC explained, “R1-R2 (Minor-Moderate) or greater radio blackouts are expected, with a slight chance for R3 (Strong) radio blackouts on days one through three (24-26 Jun) due to flare potential from region 2371.
 
How does space weather affect GNSS work?  NASA provides the following response:
In calm conditions, single frequency GPS systems can provide position information with an accuracy of a meter or less.  During a severe space weather storm, these errors can increase to tens of meters or more.  Dual frequency GPS systems can provide position information accurate to a few centimeters.  In this case the two different GPS signals are used to better characterize the ionosphere and remove its impact on the position calculation.  But when the ionosphere becomes highly disturbed, the GPS receiver cannot lock on the satellite signal and position information becomes inaccurate.
 
Geomagnetic storms create large disturbances in the ionosphere.  The currents and energy introduced by a geomagnetic storm enhance the ionosphere and increase the total height-integrated number of ionospheric electrons, or the Total Electron Count (TEC).  GPS systems cannot correctly model this dynamic enhancement and errors are introduced into the position calculations.  This usually occurs at high latitudes, though major storms can produce large TEC enhancements at mid-latitudes as well.
 
 
 Chart.png

Therefore, it is advisable to not do any GNSS work over the next three days, if possible.  As for work that was conducted during the geomagnetic storm’s most severe periods (2:00 pm – 5:00 pm EDT on June 22 and 11 pm EDT on June 22 to 2:00 am EDT on June 23) that work may need to be repeated.
 
 
 
Therefore, please always check the following SWPC webpages before doing any GNSS work:
·         3-DAY FORECAST
 
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Monday, June 1, 2015

 
NGS Releases New Beta Version of Transformational Tool
 
The National Geodetic Survey (NGS) is pleased to announce the Beta release of a new and improved transformation tool in the NGS geodetic toolkit. This redesigned version supports the transformation between geodetic coordinates and State Plane Coordinates (SPC), Universal Transverse Mercator (UTM) coordinates, Cartesian coordinates (XYZ), and U.S. National Grid (USNG) coordinates as a one-stop solution. It features transformation of single or multiple points, Web services, and software downloads. NGS encourages users to try the Beta Version and provide feedback to Krishna.Tadepalli@noaa.gov so the final version may be improved prior to release as on official NGS product.

The update was in the development stage for several months, and it provides surveyors and geodesists with a more efficient and streamlined way of accessing frequently used NGS tools in the geodetic toolkit. The new interface allows one-page easy access to transformations that were previously available only on separate pages.

The Beta version is accessible at: http://beta.ngs.noaa.gov/gtkweb
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GEOID12B Released

Thursday, April 23, 2015

​From NGS

"When using the geoid models, please be advised that GEOID12B should supersede previous models GEOID12 and GEOID12A. GEOID12B is identical to GEOID12A everywhere, except in Puerto Rico and Virgin island region. For more detail, please read Technical details."

Visit the GEOID12B page at NGS: http://www.ngs.noaa.gov/GEOID/GEOID12B/



NC-SC Boundary Commision Meeting

Monday, March 23, 2015

MEDIA ADVISORY


WHAT:  The joint boundary commission is a cooperative effort between North Carolina and South Carolina to reestablish our original common boundary, which is the official boundary, in order to minimize jurisdictional conflicts caused by the uncertain location of this boundary.  The purpose of this meeting is to discuss the proposed legislation to be filed in each state to reduce impacts on those residents and property owners affected by the clarification of the boundary.
 
WHEN:        Friday, March 27, 2015 10 a.m. to 2 p.m.
 
WHERE:     Baxter Hood Center, Bowater Room
York Technical College
452 South Anderson Road
Rock Hill, SC 29730
 
AGENDA:
10:00   Welcome, introductions, and objectives for the day
Alan-Jon Zupan, meeting moderator and co-chair of the NC-SC Joint Boundary Commission
 
10:10   Review and discussion of the proposed legislation to minimize impacts on affected residents and property owners
 
11:30   Public Comments
 
12:00   Lunch
 
12:45   Discussion on the proposed legislation (continued)


GPS on Bench Marks Webinar

Tuesday, March 03, 2015

NOAA’s National Geodetic Survey encourages anyone with survey-grade Global Positioning System (GPS) receivers or GPS-enabled phones and hand held devices to help collect GPS on Bench Marks.  This webinar will provide guidance to collect GPS observations at any time, including during National Surveyors Week (March 15–21, 2015). Joining the 2015 effort will help raise awareness about professional surveying while improving the National Spatial Reference System (NSRS).

To register and for more information on the webinar (March 5th, 3pm et), visit: http://www.ngs.noaa.gov/corbin/class_description/GPS_on_benchmarks.shtml.

For more information on GPS on Bench Marks, visit: http://www.ngs.noaa.gov/web/surveys/GPSonBM/.



 

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