| The Department of Transportation's Survey Section collects spatial data and provides the basic framework used to map, build, and maintain New Hampshires transportation systems. Pathfinder Connection Users: Please note the modified path shown in the setup instructions below.
About Our GPS Base Station Site...
The geodetic component of the Survey Section makes extensive use of Global Positioning System technology to establish a highly accurate control network and supply geodetic coordinates for all projects undertaken by the Department. We operate a full-time GPS base station for the benefit of mapping activities within the Department as well as for outside governmental and private sector mapping and surveying groups.
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| NHDOT GPS Site Details |
Datum: NAD83 (1996)
Latitude: 43 12' 46.19677" N
Longitude: 71 31' 11.47465" W
Ellipsoid height: 89.361 m (DOT levels)
Elevation Mask: 12
Logging Interval: 5 s
Rollover period: 1 hour
Antenna height: 0.000 m (ARP)
Data collected with Trimble 4000 SSE GPS receiver with a Trimble Compact L1/L2 antenna (TRM22020.00+GP) and URS software.
Site Coordinates
Station Log
Antenna Calibration Data Sheet |
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Downloading GPS Files Using Your Browser...
| Y |
MM |
DD |
HH |
.ZIP |
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Hours (UTC) |
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Day |
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Month |
| Year |
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We'd like to thank The New Hampshire Geographically Referenced Analysis and Information Transfer System (NH GRANIT) and the University of New Hampshire for their continued support and assistance. |
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Each file is named using a TYMMDDHH.zip format. T is a character identifying the data type (D for dat, S for SSF and R for rinex), Y is the year, MM the month, DD the day of the month (local day) and HH is the start time of the data file in UTC Time (24-hour format). For example, a rinex file containing data for 2:00 pm to 3:00 pm on January 15, 2002 would be named R2011519.zip
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RINEX Files (Receiver Independent Exchange Format) - developed by the Astronomical Institute of the University of Berne for easy exchange of GPS data. |
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SSF Files - Trimble Navigation Limited's proprietary data format for use with their Pathfinder Office Software. |
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DAT Files - Universal Reference Station raw GPS data, including pseudoprange, carrier phase, and ephemeris information as well as differential corrections. |
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Data Files are normally available online for at least 30 days. Data is archived by the Geodetic Survey Section of the NHDOT prior to deletion and is available on request. Users are encouraged to download data as soon as practicable.
Setting Up A Pathfinder Connection...
Below are instructions in setting up a connection in Pathfinder Office 2.51 (and later versions) to download base files automatically.
- Pull down the "Utilities" menu and select "Differential Correction."
- In "Rover Files," select a file to correct.
- In "Base Files," click "Internet Search" box and select "New."
- In "New Provider," check "Enter the details yourself."
- In "Provider Properties" many entries are optional, the required entries include:
"General" tab: "Organization" type: "NHDOT"
"Internet Server" tab: "Address Format" type: http://dot.nh.gov/gpsdata/ssf/s6%mmddhh%.zip and "Base Server Type" select: "Other, GPS Time (UTC)"
- Select "OK" and complete the set up to return to the Differential Correction screen and proceed with the corrections as usual.
Note: The "Address Format" will need to be updated every year. The "6" in "s6" reflects the last digit of the current year, i.e. 2006. This will be s7 next year. Substituting rinex/r6 or dat/d6 for ssf/s6 will link to the RINEX or DAT directories if desired.
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National Geodetic Survey - National CORS
The National Geodetic Survey coordinates a network of continuously operating reference stations (CORS) that provide GPS measurements in support of 3-dimensional positioning activities throughout the United States and its territories |
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National Geodetic Survey - Cooperative CORS
The Cooperative CORS Web Page is a mechanism by which the public can have a centralized location with links to GPS continuously operating reference stations. |
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Do you have a question or comment about this information? Contact Kerrie Hartshorn
NHDOT, P.O. Box 483, Concord, NH 03302. Tel: 603-271-1600 Fax: 603-271-7025
Email Kerrie Hartshorn |
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