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Atqasuk GPS Base Station - Base Equipment


Description:

This station is operated remotely by UNAVCO as part of general GPS support provided to the NSF-OPP Arctic program. The station is located at the former ARM Climate Research Facility (ACRF), which sites on a gravel pad on unconsolidated earth just to the southeast of town.

The geodetic quality GPS base station consists of a Trimble NetR8 GPS receiver and a Trimble Zephyr Geodetic antenna. The base receiver is not user configurable, and there is no need for users to have physical access to the receiver. The antenna is a Trimble Zephyr Geodetic mounted on the mezzanine railing of the ARM facility. Data from an on-site weather station is also inserted into the GPS data files. With proper roving equipment, the system can be used as a base for centimeter-level post-processed surveys up to a 100 km radius.

Access to Base Station data:

Although the ARM facility was decommissioned in early 2011 it is still powered, and in August 2011 a new communications link was installed by CH2M Hill Polar Services and SRI International.

This will bring up the receiver's web interface. The receiver is programmed to allow anonymous access for data download, however if prompted, the username and password are:

Username: atqk
Password: gps

The web interface also allows you 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 this 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, click on the Data Logging tab, then Data Files. Click on the Internal directory then navigate to the directory where the desired files are stored. When you locate the file(s) you want, click on the filename to download. Note that you cannot download any files that are currently being written to. The receiver records data at several logging rates, in Trimble .T01 format, stored in the following locations on the receiver:

24-hour 15-second datafiles
/Internal/YYYYMM/24hr15sc/ATQKYYYYMMDD0000A.T01

60-minute 2-Hz datafiles
/Internal/YYYYMM/DD/1hr2hz/ATQKYYYYMMDDHH00B.T01

60-minute 5-Hz datafiles
/Internal/YYYYMM/DD/1hr5hz/ATQKYYYYMMDDHH00C.T01

Each of these file types is allocated a certain portion of the NetR8 memory. When this section of memory is full, the oldest files are deleted. The NetR8 stores approximately 800 days of 15-second data, 40 days of 2Hz data, and 16 days of 5Hz data.

The 15-second data are also available from the UNAVCO data archive (site ATQK). Upon request, high-rate data files can be downloaded and made available by UNAVCO, however in general the higher sample rate data are recorded on the receiver only and are not archived. Due to the limited storage space for high-rate data on the receiver, request for archiving high-rate data should be made as soon as possible by email to projectsunavco.org.

Base Station Inventory

September 2012

ItemDescriptionUNAVCO ID #
GPS receiver Trimble NetR8 28929
GPS power/download cable (2x) Trimble
GPS antenna cable 30 m 13000
GPS 18V power supply Trimble 21421
GPS antenna Zephyr geodetic 14383

Base Station Coordinates (antenna phase center):

IRTF00:
70° 28' 19.3199" N
157° 24' 28.3269" W
28.077m HAE
Note the NetR8 receiver is programmed to record this ITRF coordinate into the GPS data files.

NAD-83:
70° 28' 19.3285" N
157° 24' 28.2019" W
27.498m HAE

Elevation above mean sea level: 30.074m MSL (GEOID-99 Alaska model applied to NAD-83 coordinates)

Coordinates explained

 

Last modified: 2019-12-24  02:12:47  America/Denver