All scientific data collected by the Australian Antarctic program (AAp) are eventually described in the Catalogue of Australian Antarctic and Subantarctic Metadata (CAASM). CAASM can be used to search through AAp data descriptions, and it also provides links to access publicly available datasets, which can either be immediately downloaded or obtained from the Australian Antarctic Data Centre (AADC).

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Citation
Bergstrom, D., Turner, P., Kiefer, K. and Shaw, J. (2004) Differential GPS data collected at Heard Island 2003/04 for the Regional Sensitivity to Climate Change in Terrestrial Ecosystems (RiSCC) program, Ver. 1, Australian Antarctic Data Centre - https://data.aad.gov.au/metadata/ASAC_1015_HIGPS03_04, Accessed: 2025-04-15
Title
Differential GPS data collected at Heard Island 2003/04 for the Regional Sensitivity to Climate Change in Terrestrial Ecosystems (RiSCC) program
Data Centre
Australian Antarctic Data Centre, Australia
Created Date
2004-07-29
Revision Date
2019-04-02
Parent record
None

Description

Metadata notes for RiSCC Heard Island 2003_04 season (ASAC 1015) - DGPS data and Base Station data DGPS data are described below, and associated data files listed.

1. Three Island study - Phenology and Morphology of Heard Island vascular plants. This study uses a combination of latitudinal and altitudinal investigations to separate the effects of temperature per se and seasonality on the phenology and morphology of plants. Most latitudinal studies are confounded by covariation of seasonality and temperature, whereas with altitudinal variation at different latitudes one can disentangle these effects. The presence of the Polar Frontal Zone (APFZ), which has a major effect on seasonality, would be a key feature that would enable us to investigate this. Three islands (Marion, Kerguelen, Heard) were used in the study, each of which lies in a different place relative to the APFZ and each of which is inhabited by a similar suite of species, thus removing confounding effects of species identity in understanding responses.

1a Phenology data
The collection of positional data for Heard Island Scarlet Hill Phenology was collected at each site; 4 m, 50 m, 100 m, 200 m and 250 m (ASAC 1015). At each site plants of Pringlea antiscorbutica, Acaena magellanica, Poa cookii and Azorella selago were chosen (NB at 100m and 200 m no Acaena magellanica was present, and at 250 m only Pringlea antiscorbutica was sampled) within a 50 x 50 m area, where possible, and were deemed typical of the site. Only healthy mature plants at each site were chosen. At the 4 m, 100 m and 200 m altitude levels, sites were established around AWSs (Automatic Weather Stations). Each plant was flagged and numbered. Numbered flags were removed from around/beside plants at the end of the study. The numbers of plants are represented in the GPS data. Positional data are in the form of points, lines and areas. The positional data are found in the following files.

4 m phenology
PT021412A.SSF4 m phenology data, N15 Poa cookii data, Poa annua record, 50 m phenology data JDS011811A.SSFcoastal study area, AWS site and phenology site

50 m phenology
JDS012314A.SSF50 m phenology (Scarlet Hill) and Stephenson camp location
PT020910A.SSF50 m Azorella phenology, water meadow and Poa cookii N15 sites

100 m phenology
JDS020714A.SSF200 m Phenology and 100 m AWS and phenology data
JDS021313A.SSF100 m Phenology (Pringlea)
PT021614A.SSF250 m and 200 m phenology data, 100m phenology

200 m phenology
JDS020712A.SSF200 m Phenology site and AWS
JDS020714A.SSF200 m Phenology and 100 m AWS and phenology data
PT021614A.SSF250 m and 200 m phenology data, 100m phenology

250 m phenology
PT021614A.SSF250 m and 200 m phenology data, 100m phenology

1b Morphology data
DGPS points were only taken by JDS from Fairchild Beach morphology collection sites.

JDS0104.SSFAcaena magellanica, Fairchild Beach morphology JDS010511ATR3.SSFFairchild Beach morphology

2. Positional data for the mapping of the distribution of Ranunculus crassipes The distribution of Ranunculus crassipes at Heard Island was mapped between the 14-1-2004 and 15-2-2004. This mapping was undertaken by JDS, PT and JJS. Data were collected from the Skua Beach bluffs to Sooty Valley. Positional data are in the form of points, lines and areas. Data include areas of rock water meadow. The positional data are found in the following files.

PTRAN021513A.SSFRanunculus crassipes transect, points and rock water meadow JDS020816A.SSFRanunculus crassipes mapping on Skua bluffs JJS011417B.SSFRanunculus crassipes mapping on Skua bluffs
PT020910A.SSF50 m Azorella phenology, water meadow and Poa cookii N15 sites

This mapping of the distribution of Ranunculus crassipes together with mapping of Carex trifida and Poa litorosa on Macquarie Island described by the metadata record with ID ASAC_1015_MIGPS03 contributed to the paper:
Bergstrom, D.M., Turner, P.A.M., Scott, J., Copson, G. and Shaw, J. (2006) Restricted plant species on sub-Antarctic Macquarie and Heard Islands. Polar Biology 29 532-539.

3. High altitude vascular plant points and transect data Records of high altitude plants were taken by JDS and RC. Some data from the files JDS012510A.SSF and JDS012510A_CPscarlet.ssf have not been corrected, as stated above.
JDS012510A.SSFScarlet Hill high altitude transect JDS012510A_CPscarlet.ssfScarlet Hill high altitude transect - control points only for JJS JDS013111A.SSFLong Beach high altitude data and Apple location JDS020112A.SSFLong Beach high altitude data RC0302.SSFRobb Clifton control points for JJS 'and high altitude'
RC0402.SSFRobb Clifton control points for JJS 'and high altitude'
RC0502.SSFRobb Clifton control points for JJS 'and high altitude'

Other datafiles recorded by PT, JDS and RC under ASAC 1015 include PT022012A.SSFFuel drum retaining wall, Spit Camp JDS012113A.SSFWinston Lagoon JDS012415A.SSFAcaena - 100 m south edge of Scarlet Hill JDS012914A.SSFLambeth 1 JJS Control point JDS123112A.SSFPoa annua - Dovers moraine JDSPHOTO020118A.SSFPhoto points - Dana Bergstrom data
PT010621A.SSFSK25 - not sure what this data are RC0202.SSFRobb Clifton control points for JJS

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Quality

Positional data were collected from areas between Long Beach to Sooty Valley (Heard Island) using Global Positioning System (GPS) equipment (Trimble GeoXT CE series handheld GPS units) and standard observational techniques. The collection of positional data were undertaken between 23-12-2003 and 21-2-2004. The GeoXT units are mapping grade, single frequency receivers capable of decimetre accuracies over short baselines (less than 5 km).

DGPS data were collected by Perpetua Turner (PT), Justine Shaw (JDS), Jenny Scott (JJS) and Robb Clifton (RC). These staff are highly qualified in the use of the GPS equipment (Ultimate Positioning, Melbourne). Between the 30-12-2003 and 21-2-2004 a Trimble ProXR receiver operating as a base station was used. At Heard Island, the receiver was located beside a Geoscience Australia receiver set up at the AUS094 survey mark, Spit Bay Camp. The survey mark is situated on a rock stack behind the base camp at 10.869 m asl. The baseline distance between the mobile receivers at the Sooty Valley field site and Spit Bay camp was less than 5 km. The base station logged data at 5 second intervals.

Post processing (differential correction) of the GeoXT data against the Spit Bay base station data were achieved using Trimble GPS Pathfinder Office (2002). The estimated accuracy for the GeoXT data are at the 25 cm level in both the horizontal and vertical components. Results from post processing were imported in ArcView (2002) and projected onto the Australian Map Grid (WGS 1984). All data recorded during the time of base station operation has been differentially corrected, except for some features within the files JDS012510A.SSF and JDS012510A_CPscarlet.ssf where the base station was not operating.

A data dictionary was set up (PT) using the Feature Type Catalogue found on the AADC website http://data.aad.gov.au/aadc/ftc/search_ftc.cfm and GPS Pathfinder Office 2.90,Trimble Navigation Limited. This Data dictionary is called phendict.ddf (phendict.txt) and includes three scientific site features (point, area and line) and one site record feature (point, for environmental monitoring and permit requirements). No new additional attributes for these features have been added to the final corrected data.

Each datafile is represented in two forms. Files with the extension SSF (standard storage format) have been downloaded from the GPS unit. All SSF files are data files and are stored in the latitude/longitude coordinate system, using the WGS-84 datum. SSF files are transformed into the currently configured coordinate system. If the currently configured coordinate system is a local site, the site adjustment will be included in the transformation. Files with the extension COR are differentially corrected data files. COR files are the end product of differential correction of SSF files in GPS Pathfinder Office 2.90,Trimble Navigation Limited.

Each file does not necessarily relate to one particular project. File names are deciphered as follows:
JDS011811A.SSF
JDS - intials of file creator (Justine Shaw)
0118 - mm/dd, January 18th.
11 - 24 hr clock, 11.00 hours.
A - the first file made within that hour - subsequent files created in the 11th hour are named B, C, D, etc.
JDSPHOTO020118A.SSF
JDS - initials of file creator (Justine Shaw)
PHOTO - refers to the contents of the file, ie. photo points
0201 - mm/dd, February 1st.
18 - 24 hr clock, 18.00 hours.
A - the first file made within that hour - subsequent files created in the 18th hour are named B, C, D, etc.

Base station datafiles.
The basestation (Trimble Reference Station (TRS) 1.02, Copyright 1999 Trimble Navigation Limited) stored data in five files: Almanac, Dat, Log, Rinex and SSF.
An almanac file contains orbit information, clock corrections, and atmospheric delay parameters for all satellites tracked. It is transmitted to a receiver from a satellite and is used by mission planning software such as Quick Plan. This file type has an .ssf extension.
Dat files (.dat extension) are the standard data file used for survey applications. Dat files are produced by survey grade receivers such as the 4700 GPS receiver.
A Receiver Independent Exchange (RINEX) file is a set of standard definitions and formats designed to be receiver or software manufacturer independent and to promote the free exchange of GPS data. The RINEX file format consists of these separate files:
The observation (.obs extension) file, containing the raw GPS data, The navigation (.nav extension) file, containing satellite position and time information Log files (.log extension) containing any information, warning, error, or critical messages generated by the TRS software appear in the Messages window, if it is enabled. This file is a standard ASCII text file.
A Standard Storage Format (.SSF extension) file is a Trimble standard data file designed for mapping applications. Survey SSF files use a different format from GIS and mapping SSF files.
TRS does not generate survey SSF files.

The zip file available for download with the base station data includes the base station location and information about the calculation of this location.

Access

The data are available for download from the provided URLs.

Temporal Coverages

Spatial Coverages

Data Resolution

Latitude Resolution:
1 Metre(s)
Longitude Resolution:
1 Metre(s)

Science Keywords

Additional Keywords

  • ALTITUDE
  • DGPS
  • GPS
  • HEARD ISLAND
  • LATITUDE
  • LONGITUDE
  • MAPPING
  • PHENOLOGY
  • MORPHOLOGY
  • TRIMBLE
  • VEGETATION

Locations

  • OCEAN > SOUTHERN OCEAN
  • GEOGRAPHIC REGION > POLAR
  • OCEAN > SOUTHERN OCEAN

Platforms

  • FIELD SURVEYS
  • FIELD INVESTIGATION

Instruments

  • Global Positioning System
  • GPS RECEIVERS

Researchers

  • bergstrom, dana (INVESTIGATOR)
  • turner, perpetua (INVESTIGATOR,TECHNICAL CONTACT,DIF AUTHOR)
  • kiefer, kate (INVESTIGATOR)
  • shaw, justine (TECHNICAL CONTACT)
  • smith, david (DIF AUTHOR)

Use Constraints

This data set conforms to the CCBY Attribution License (http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1015_HIGPS03_04 when using these data.

Creative Commons License