NSW Positioning Theme Survey Mark GDA94 multiCRS

MultiCRS service - supporting requests in multiple Coordinate Reference Systems - Information Sheet

A new series of ‘multiCRS’ web services have been published to support GDA2020. These new ‘multiCRS’ services:

· have a spatial reference of GDA2020

· support alignment with GDA2020, GDA94 or [WGS 84-aligned-to-GDA2020] GIS environments,
using built-in server-side transformations:

o GDA94 < NTv2-CPD > GDA2020

o GDA94 < NTv2-CPD > WGS 84 aligned to GDA2020

o GDA2020 < NULL > WGS 84 aligned to GDA2020

Note: ESRI software will automatically align by transforming from the sourceSpatialReference (GDA94).
Other software may need to set client-side transformations from the SpatialReference (GDA2020).

Note: Client-side transformation(s) can be used to over-ride these default transformations.

The original [WGS 84-aligned-to-GDA2020] is still available, without the ‘multiCRS’ suffix. In due course, and allowing time for user feedback and testing, it is intended that the original service name will adopt this new multiCRS functionally.

This service provides GDA94 coordinates, heights and related information for NSW survey marks that form the official State control survey network (as reported in SCIMS). This service controls the precision of numerical output in a manner that mirrors SCIMS Online available through the Spatial Services Portal.

The web service provides a wealth of data on each mark, including:

mark type (Permanent Mark, State Survey Mark, etc.)
mark number
horizontal coordinates and their accuracy (class and order)
heights and their accuracy (class and order)
status of the mark (destroyed, restricted access, etc.)

The mark type is represented using various shapes and the accuracy of the mark (both vertical and horizontal) is communicated by the colour.

This web service allows users to easily integrate survey control mark data from SCIMS into Open Geospatial Consortium (OGC) compliant spatial platforms and applications.

Data provided by the NSW Survey Mark web service can be used in a variety of engineering and surveying applications, including but not limited to:

cadastral survey planning
flood studies and hydrographic modelling
infrastructure development
site calibration at construction sites
elevation modelling
preservation of survey infrastructure.

The NSW Survey Mark web service gives users an alternative method to access state control survey data that can be incorporated into their GIS package without needing to log into SCIMS Online.

Please note that SCIMS Online is the official option for obtaining state control survey data for cadastral surveys as it offers legal traceability. SCIMS online is accessible via the Spatial portal.

Metadata

Type	Esri Feature Service
Update Frequency	As required
Contact Details	Contact us via the Spatial Services Customer Hub
Relationship to Themes and Datasets	Positioning Theme of the Foundation Spatial Data Framework (FSDF), Survey Control Information Management System (SCIMS)
Accuracy	The dataset maintains a positional relationship to, and alignment with, the Lot and Property digital datasets. This dataset was captured by digitising the best available cadastral mapping at a variety of scales and accuracies, ranging from 1:500 to 1:250 000 according to the National Mapping Council of Australia, Standards of Map Accuracy (1975). Therefore, the position of the feature instance will be within 0.5mm at map scale for 90% of the well-defined points. That is, 1:500 = 0.25m, 1:2000 = 1m, 1:4000 = 2m, 1:25000 = 12.5m, 1:50000 = 25m and 1:100000 = 50m. A program of positional upgrade (accuracy improvement) is currently underway.
Source Reference System (dataset)	Geocentric Datum of Australia 1994 (GDA94), Australian Height Datum (AHD)
Spatial Reference     (web service)	Geocentric Datum of Australia 2020 (GDA2020), Geographic 2D
WGS 84 Equivalent To	GDA2020
Spatial Extent	Full state
Standards and Specifications	Open Geospatial Consortium (OGC) implemented and compatible for consumption by common GIS platforms. Available as either cache or non-cache, depending on client use or requirement. The web service is built as per Spatial Services project specification.
Distributors	Service Delivery, DCS Spatial Services 346 Panorama Ave Bathurst NSW 2795
Dataset Producers and Contributors	Survey Operations, DCS Spatial Services 346 Panorama Ave Bathurst NSW 2795