McMurdo Station GPS Survey System - Base Station
Base Station MCMD
This station is operated remotely by UNAVCO as part of general GPS support provided to the NSF-OPP Antarctic program.
The geodetic quality GPS base station at McMurdo Station consists of a Trimble NetR8
GPS receiver, attached via an antenna splitter to an AOA Dorne Margolin choke ring antenna (shared with IGS station MCM4), along with
an RTK base radio and antenna. The base receiver and radio are located inside the foyer of the NASA Ground Station building (building 71).
The GPS antenna is mounted to a concrete pad on a small hill in front of this building. RTK radio antenna is an omni-directional whip antenna,
mounted at the top of a tower on the southern side of the building (facing McMurdo Station).
A Pacific Crest radio transmitter is connected to receiver MCMD, and
broadcasts real-time kinematic (RTK) corrections to allow local real-time surveys and stakeouts up to 5 km from McMurdo Station.
The base can also be used for post-processed surveys up to a 100 km radius. The system is considered to be a permanent base station,
and is not intended to be moved or disconnected.
- Trimble NetR8 user guide [pdf]
Coordinates
Base station MCMD coordinates (bottom of antenna). Antenna is Allen Osborn Associates (AOA) Model T Dorne-Margolin Choke Ring with JPLA radome.
| Coordinate | Value | Ref. Frame |
| Latitude | 77° 50' 18.0553" S | ITRF-96 |
| Longitude | 166° 40' 09.574" E | ITRF-96 |
| Height Above Ellipsoid (HAE) | 98.040m | ITRF-96 |
| Elevation Above MSL | 151.430m | EGM96 |
Data Download
Users at McMurdo Station can download data from the Trimble NetR8 web interface:
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: mcmd
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/MCMDYYYYMMDD0000A.T01
60-minute 2-Hz datafiles
/Internal/YYYYMM/DD/1hr2hz/MCMDYYYYMMDDHH00B.T01
60-minute 10-Hz datafiles
/Internal/YYYYMM/DD/1hr10hz/MCMDYYYYMMDDHH00C.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 8 days of 10Hz data.
The 15-second data are also available from the UNAVCO data archive
(site MCMD). Each summer season, from late October through mid February, high-rate data files are downloaded and archived 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, any group requiring high-rate GPS data from this station should make a formal request
as soon as possible by emailing archive-gps
unavco.org.
Base Station Inventory
September 2012
| Item | Description | UNAVCO ID # |
| GPS receiver | Trimble NetR8 | 28928 |
| GPS power/download cable | Trimble | |
| GPS 18V power supply | Trimble | |
| GPS antenna | AOA Choke Ring; shared with IGS station MCM4 | S/N 363 |
| GPS RG58 antenna cable | N to N | |
| GPS RF adapter | N to TNC | |
| GPS Heliax antenna cable | shared with IGS station MCM4 | |
| GPS 1x4 powered antenna splitter | GPS Source; shared with IGS station MCM4 | |
| RTK radio | Pacific Crest RFM96W | 11143 |
| RTK radio power supply | 25747 | |
| RTK radio power/serial cable | Pacific Crest | |
| RTK radio LMR400 antenna cable | ||
| RTK radio RG58 antenna cable |
Last modified: 2019-12-24 02:12:46 America/Denver