Base Station SMM1

A geodetic quality GPS base station is located in the Green House at Summit Camp. The system consists of a Trimble NetRS GPS receiver with Zephyr Geodetic antenna, a Trimble HPB450 radio transmitter, and a shared computer for data downloading and processing. Data can be logged for post processing, and a real-time kinematic (RTK) broadcast allows local real-time surveys and stakeouts. The base will support RTK surveys up to 5 km from Summit Camp, and post-processed surveys over 100 km away. A Vaisala WXT-510 Weather Station is also installed at Summit Camp. Data from this station is injected into the GPS data files for use in atmospheric water vapor monitoring. The system is considered to be a permanent base station, and is not intended to be moved or disconnected. Note: the Vaisala weather station was removed in 2009 after failure. It may be replaced in the future. An inventory of base station components is maintained here:

• Base Station Inventory

The Green House facility was moved between June 30 and July 2 2009. At this time the base station location changed by ~80 meters, therefore the station name was changed from SUMM to SMM1 and a new coordinate was generated for use in the RTK broadcast. As of July 2 2009 the RTK base station coordinate (0m to bottom of antenna mount) is:

ITRF: For precise geodesy, the International Terrestrial Reference Frame (ITRF) is used. Unlike NAD-83, WGS-84, and other datums, ITRF also incorporates tectonic plate velocities. Therefore, when referring to ITRF coordinates, one must also provide the date that the coordinates refer to. See the on-line NGS calculator for reference frame transformations.

Base station data can be downloaded here (from the Summit Camp local network only):

• Online access to NetRS base receiver (rtkgps.summitcamp.org   or   summitcamp.org:34080/)

The Trimble NetRS web interface should appear. Here, you can click on the left-hand menu to see how many satellites the receiver is tracking, what data files are being logged, and other configuration information. However, you can only download data using the Summit user account and cannot change any of these parameters. Configuration changes are done remotely by UNAVCO using a separate account; contact UNAVCO for any changes or requests.

To download data, next click on “Data Logging” then “Data Files”. A listing of directories in “yyyymm” format will appear where yyyy is the year and mm is the month. Click on the appropriate month. This directory will contain 24-hour files with the 15-second low-rate data. The 1-second high-rate data will be stored in subdirectories listed by two-digit day. When you locate the file(s) you want, click on the filename. When you save the files, they will automatically appear on your computer’s desktop. Note that you cannot download any files that are currently being written to. The username and password for Summit users are:

Username: smm1 (or summ)
Password: gps

Data from the base station are also available online from the UNAVCO Data Archive.

Last modified Thursday, 09-Jul-2009 18:10:29 UTC

Home | About Us | Contact Us | Support | Search | Facility | PBO | Education & Outreach

Comments: webmasterunavco.org
© 2010 UNAVCO, Inc.