Transcript GPS and Geodetic News You Can Use David Conner

GPS and Geodetic News You Can Use
David Conner
Geodetic Advisor to the State of Ohio
National Geodetic Survey, NOAA
2008 Ohio GIS Conference
September 10-12, 2008
Crowne Plaza North Hotel
Columbus, Ohio
TOPICS
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Overview
National Readjustment - NAD83 (NSRS2007)
GPS CORS, OPUS, OPUS-DB, and more
County Scorecard
Shifts in Ohio
NAD 83 (1995) vs NAD 83 (NSRS2007)
Horz Shift Average : 0.016 m (Max: 0.348 m)
Vert Shift Average : 0.013 m (Max: 0.503 m)
Example actual horizontal shifts at station SMITH (JY0742)
NAD 27 vs NAD 83 (1986)
NAD 83 (1986) vs NAD 83 (1995)
NAD 83 (1995) vs NAD 83 (NSRS2007)
~ 13 meters
~ 20 cm
~ 1.5 cm
For Stations not Included
In the NSRS (2007) readjustment
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NGS recommends that NAD 83 data that is not part of the
NSRS readjustment be readjusted using original
observation data
Because of the relatively small shifts involved
transformation software such as NADCON will not be
developed for NAD 83(NSRS2007)
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NADCON accuracy
NAD 83 (NSRS2007) avg shift
~ 6 cm (0.2 ft)
~ 2.5 cm
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NGS will streamline the process of project acceptance
• OPUS DB – coming soon - ?
Ohio’s GPS
CORS Network
Brought to you courtesy of the ODOT,
Bureau of Aerial Engineering
VRS/ CORS information
Telephone: 614-275-1372, or
614-351-2839.
[email protected]
CORS/OPUS:
Overview & Status
CORS = Continuously Operating Reference Station
The CORS network contains
about 1,250 GPS tracking
stations, and it is growing by
about 200 stations per year.
OPUS is a Web-based service
enabling users to automatically
post-process GPS data.
Vertical standard error achievable when a user submits 15
minutes of GPS data to OPUS-RS
OPUS FLAVORS
Try it …
http://beta.ngs.noaa.gov/CORSProxy/oraOpusDbWeb/
OPUS-DB
OPUS-DB
Sample
Datasheet
OPUS 
Datasheet Concept
GPS data requirements
NGS-modeled
antenna
GPS data
(4+hr, good stats)
“OPUSable”
4+ hours of dual frequency data
NGS-calibrated antenna
OPUS must achieve:
≥ 70% observations used
≥ 70% ambiguities fixed
≤ 0.04m peak-to-peak horizontal
≤ 0.08m peak-to-peak vertical
≤ 0.03m RMS
metadata requirements
observation
antenna
type,
notes
height
control station
photo *
control station
description *
*optional for “existing” stations.
Simplified bluebooking
NOAA’S County Scorecard
• NOAA has a relatively new performance metric that assesses how well
we are doing at “enabling” local capacity for accurate positioning. This
metric:
 Makes use of NOAA’s Online Positioning User Service (OPUS) as a proxy to
assess the local use of NOAA positioning tools and services. Was developed over
the past several years in partnership with National Association of County Surveyors
(NACS).
 Involves the use of a web-based county scorecard of 23 survey questions
specifically focusing on infrastructure, NGS models and tools, NGS capacity
building and outreach, and overall satisfaction.
• We need input from YOU, our core customers, to help NOAA
improve its geospatial products and services.
• For more information, visit http://www.ngs.noaa.gov/scorecard/
or contact:
 Your NOAA State Geodetic Advisor, in Ohio [email protected]
(for current list of all Advisors visit http://www.ngs.noaa.gov/ADVISORS/)
OR
 Brett Howe ([email protected])
We want
YOU
to tell us
how we’re
doing
County Scorecard Details
Our Performance Metric Asks
• Are Counties using NOAA’s positioning products and services?
 NOAA looks at County Online Positioning User Service (OPUS) use as a proxy. Have
there been 25 or more OPUS solution generations in a given county in the last 12
months?
 Counties meeting the above criteria are “substantially enabled” (shaded yellow).
• Is there feedback and interaction between the local community and
NOAA?
 Is the County in a State that participates in the NOAA State
Advisor/Coordinator program?
 Has a County Geospatial Representative been identified (eg
County Surveyor, County Engineer, GIS Administrator, or
equivalent)?
 Has “blue book” data from the County been submitted to NGS
through activities such as: leveling project software, GPS projects
and OPUS DB (when available)?
 Has a County Scorecard web survey been filled out by the County
Geospatial Representative?
 Counties meeting the above criteria are “fully enabled” (shaded
green).
NOAA’S County Scorecard
How you can help …