Title

Gravity Reading Locations and Measurement 

Alternate title

GRAVITY 

Supplemental Information

History: Gravity data collected dominantly on roads/tracks etc., Elevation data associated with gravity readings collected using various technics (traditional surveying, barometers, GPS, etc.) Related Documents: None 

Status

Completed  

Horizontal Accuracy

25m  

Code

4283 

Maintenance and update frequency

Irregular  

Topic category

• Geoscientific information

Use limitation

The data are available free of charge from DPI's Minerals and Petroleum Online Store at www.dpi.vic.gov.au/minpet/store and from the "Geoscience Portal" at www.geoscience.gov.au through the Geophysical Archive Data Delivery System (GADDS). The data is subject to Crown Copyright and interested parties are required to enter into a licence agreement that can be obtained from the custodian. Subject to licence conditions 

Classification

Unclassified  

Statement

Dataset Source: The dataset is compiled from data acquired by GeoScience Victoria (GSV), Geoscience Australia (GA) and private companies from 1949 to 2007. Station spacings vary from 11 km to 10 m. The position data are based on the GDA94 datum for horizontal coordinates and the AHD for vertical coordinates. The gravity data are based on the IGSN71 datum and gravity units are micrometres per second squared. Simple and complete Bouguer anomaly values have been calculated using a density of 2.67 g/cc. A NULL value of 99999 has been used for fields where terrain corrected data is not currently available. Each gravity survey has a unique survey identifier (surveyid). Additional metadata for individual gravity surveys is available from the Index of Gravity Surveys maintained by Geoscience Australia. Dataset Originality: Derived 

Description

Collection Method: Various 

Description

file copied to /arc/p_mpv/import/geophys/vicgrav_located_data_28_11_02_db.dat then in mpv arcinfo project import_gravity2mpvcgdl is run to generate the points and copy them to /cdb_mpv/l100-gmpv areas 

Classification

Unclassified  

Attribute Quality

Comments

Good 

Positional Accuracy

Comments

Highly variable, ranges from 100's m horizontal error with 10's m vertical error for early surveys where positions were taken from base maps with vertical positions from analogue barometers, to millimetre accuracy for horizontal and vertical positions using post-processed differential GPS and modern surveying methods. 

Conceptual Consistency

Comments

Good 

Missing Data

Comments

Complete Completeness Verification: Metadata Custodian Review Frequency: yearly Metadata Last Reviewed by Custodian: February 2008 

Excess Data