Title

Morphological features 

Alternate title

MORPH25 

Purpose

Morph25 is a key layer at 1:25,000 for departmental operational activities that require morphology and related line, point and annotation features. 

Credit

Phill King, Sandro Condurso 

Supplemental Information

History: Data has been derived from Land Victorias State Digital Map Base - Topographic (SDMB-T) and converted from Microstation DGN format to Arcinfo format. All features have been AS2482 coded including annotation. This cover has annotation at 1:25,000 which may be used at alternative scales of up to 1:50,000, given the nature in which annotation has been justified. Relationship to other Datasets: Line work described in this layer will contribute to lines and points located in both CONT25 and ROAD25. Current Design Issues: The layer has been defined to allow for differentiation of morphological features according to the Australian Standard AS2482 - 1989. The layer consists of lines and points representing morphology and related features. Annotation present for this layer is in the subclass MORPH25 and is AS2482 coded for features they describe. Future Design Issues: Subject to proposed draft Australian / NZ Standard DR97068 geographic information - data dictionary. Related Documents: None Natural Resources & Environments 1:25,000 Topographical Base Datasets - Phill King - NRS (May 1997) SDMB-T in the Corporate Geospatial Library - Phill King, Sandro Condurso - NRS (1998) 

Status

Obsolete  

Horizontal Accuracy

25m  

Maintenance and update frequency

As needed  

Title

DIGITAL Arc/Info Revision 7 Librarian layer 1 

Topic category

• Geoscientific information

Classification

Unclassified  

Statement

Dataset Source: Land Victoria 1:25,000 State Digital Map Base - Topographic Dataset Originality: Primary 

Description

Collection Method: Maps 

Description

The data was received in an Arcinfo format in a single file containing all features as described on a published 1:25,000 map, including annotation and symbology defined as arcs. Prior to insertion in the library the data underwent the following processes: Line features separated into individual covers based on AS2482 Line covers then unsplit on AS2482 Line, point and annotation then sorted into appropriate layers 

Classification

Unclassified  

Attribute Quality

Comments

Coding on all features has been validated by Land Victoria during the creation of the State Digital Map Base - Topographic from scanned repromats of published 1:25,000 maps. "The allowable error in attribute accuracy ranges between a 1% allowable error to 5% error. For this product attribute accuracy ranges between a 1% to 5% error. For this product attribute accuracy is a measure of the degree to which features and attribute values of spatial objects agree with the information on the source material." (Geospatial Information SDMB-T Metadata 1998) 

Positional Accuracy

Comments

"The planimetric accuracy attainable will be the sum of errors from three sources: · the positional accuracy of the source material · errors due to the conversion process · errors due to the manipulation process" (Geospatial Information SDMB-T Metadata 1998) Precision: Source Data: 1:25 000 topographic maps Horizontal accuracy - 90% of well defined points will fall within +/- 12.5m of true position Vertical accuracy - 90% of elevations will fall within +/- 0.5 a contour interval which are at 10 or 20 metres Digital Data: Any departure between the digital and source material (measured between centrelines) will not exceed 0.5mm at map scale (i.e. 12.5m at 1:25,000) with a root mean square of 0.12mm for any random sample. Exceptions: There are 38 mapsheets that are sub-standard due to survey control problems and small scale photography. There is up to 50 metre error in some features. These will be recompiled when the remainder of the data capture progam is complete. For a list of these mapsheets and their status please contact Natural Resource Systems Branch - Mapping. Determination: Survey controlled with 8 points per mapsheet with a residual error less than 10m at ground scale 

Conceptual Consistency

Comments

All coverages go through a checking procedure that includes: item validation (sourced, sourcea, and version) "The allowable error in attribute accuracy ranges between 1% to 5% error. Logical consistency is a measure of the degree to which data complies with the technical specification. The test procedures are a mixture of scripts, microstation MGE program and on-screen visual checks." (Geospatial Information SDMB-T Metadata 1998) 

Missing Data

Comments

All of the State is covered by data in the DNRE CorporateGeospatial Data Library with the exception of information currently held by NSW Land Information Centre as per the cross border agreement 1997. "The completeness of the data is tested by visual comparison to the source material. This test may be either on-screen visual checks or overlay symbolised plots compared to the source material. The SDMB-T is still being produced to complete capture stage that will reflect the information levels contained on a printed 1:25 000 topographic map. At present there is a number of different capture data sets. · freeways, highways, roads, and tracks · rivers, creeks and hydrographic features · contours at 10 and 20 metre intervals · railway lines The data set produced by digital stereo capture covering 20% of the State contains all levels of information except for text and information relating to administrative boundaries. Other data sets have varying degrees of data capture beyond the mandatory requirements. The remaining data set required to complete the data capture over the whole of the State is currently being captured by private contractors." (Geospatial Information SDMB-T Metadata 1998) All of the State is covered by data in the DNRE CorporateGeospatial Data Library with the exception of information currently held by NSW Land Information Centre as per the cross border agreement 1997. "The completeness of the data is tested by visual comparison to the source material. This test may be either on-screen visual checks or overlay symbolised plots compared to the source material. The SDMB-T is still being produced to complete capture stage that will reflect the information levels contained on a printed 1:25 000 topographic map. At present there is a number of different capture data sets. · freeways, highways, roads, and tracks · rivers, creeks and hydrographic features · contours at 10 and 20 metre intervals · railway lines The data set produced by digital stereo capture covering 20% of the State contains all levels of information except for text and information relating to administrative boundaries. Other data sets have varying degrees of data capture beyond the mandatory requirements. The remaining data set required to complete the data capture over the whole of the State is currently being captured by private contractors." (Geospatial Information SDMB-T Metadata 1998) 

Excess Data