NTDB & NTMS Specifications (250K & 100K)
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Updated: 1 December 2007
The Feature Type dictionary layout
1. Introduction
This Feature Type Dictionary layout page provides an explanation of the structure of an entry in Feature Type Dictionary. It details each aspect of the entry including, where applicable, how and in what context the field should be used.
In addition, at the end of this page is a sample entry. This entry shows the location of each field and may, when applicable, provides some examples of how they could be populated.
2. Structure of an Entry
| Field |
Explanation |
| Scales |
This gives the scales to which the feature type applies. Some feature types are only used for 1:25 000, 1:100 000 or 1:250 000 mapping and Geodatabase, others are used at mulitple or all scales. |
| Feature Type |
The feature type classification to which the entry relates. |
| Feature Class |
The feature class in which the feature type classification is contained |
| Feature Dataset |
The feature dataset in which the feature type classification is contained. |
| Geometry Type |
This is the spatial object type; Polygon, Line, Point or Annotation |
| Definition |
The definition which applies to the feature type.
Classification of features is to be based on their match to the feature type definition and not their name. For example, an area named Williams Swamp may need to be classified as Land Subject to Inundation when it meets the definition of a Land Subject To Inundation but not the definition of a Swamp. |
| Minimum Size Criteria |
The size criteria for 'inclusion' and 'data capture or map representation'.
The minimum size for 'inclusion' criterion documents the size a feature must meet before it can be incorporated into the specified scale database when the information is derived from a Geoscience Australia sanctioned 'base material'.
The minimum size for 'data capture or map representation' criterion documents the size a new feature (excluding those derived from a Geoscience Australia sanctioned 'base material') must meet before it can be captured from reference material (such as imagery). In addition this size criteria determines the first level of filtering for features to be represented on the standard mapping series for each scale (e.g. 1:100 000 NTMS)
The main occasions where the 'inclusion' and 'data capture or map representation' size varies is in the 1:100 000 scale category, in which cases, the base material will generally be derived either from the 1:25 000 data capture program, the repromat of the previous 1:100 000 edition maps covering the same area or information from internal 'single point of truth datasets'.
Length Criteria may apply to linear features such as roads, watercourses and canal lines. Area criteria may apply to polygons or in certain cases to point features, such as buildings, to minimise capture of features of little value (e.g. garden sheds).
Minimum sizes for 'inclusion' and 'data capture or map representation' have been documented not only for 1:100 000 and 1:250 000 scales but also for 1:25 000 to cater for the increasing large scale capture work being conducted at present which will feed into the TOPO100K and TOPO250K NTDBs.
All newly captured features obtained from any revision source material/imagery must comply with the size criteria as stated in these specifications.
Length and area criteria is defined using metres on the ground.
Length criteria will not apply to features that join two or more features in the same network at each end.
The minimum area & length criterion indicated for a polygon and linear features respectively, will apply to the full size of the feature in the real world.
This means that in the case of Built Up Area & Island feature types as well as the Reserves feature class where multipart polygons exist, the size criteria will apply to total area formed by its component parts.
Also, when capturing new features within a work package extent, if the portion within the work package is smaller then the minimum size for inclusion but it is known that the full extent of the feature in the real world meets or exceeds the size criteria, then the portion within the work package should be captured.
Further clarifications to the use of the minimum size for inclusion criteria may be documented within the Geodatabase Rules for each entry. |
| Data attributes |
The data attributes define the applicable fields in the geodatabase model for each feature type and the acceptable values. As all items for all scales applicable to the feature type are listed in the data attributes definitions in appendix a, it is recommended that it should be read in conjunction with Section 3 Chapter 4.1 Structure Overview which lists which items are applicable at which scale.
For each field, a field descriptor eg FEATURE RELIABILITY DATE is followed by the field code in round brackets e.g. (FEATURERELIABILITY) and the data type in square brackets e.g. [Date; Standard Format; No] and then a brief description e.g. 'The reliability date of the spatial object'. This information may be followed by legal entries used in the field and any qualifiers as required.
The data type definitions are based on standard ArcGIS data types. The following are examples of the definitions used and their meaning. Please Note: That information denoting where a field may or may not be allowed null values has only be indicated with a singular value, at times they may be formated 'Yes(No)' or 'No(Yes)' with the value in the bracket being a variation when a item is created at the 1:250 000 scale.
[Date; Yes; 0; 0; 36; Pop_Req] This means the field is a date field using standard ArcGIS format with the yes indicating null values are allowed. It has a precision of 0, a scale of 0 and a length of 36. Item must always be populated with a value.
[Double; Yes; 18; 11; Pop_Req] means a numeric field, with the yes indicating it allows null values. It has a precision of 18 and a scale of 11.Item must always be populated with a value.
[Float; Yes; 6; 2; Pop_Req] means a numeric field, with the yes indicating is allow null values. It has a precision of 6 and a scale of 2.Item must always be populated with a value.
[Integer; No; 6; Pop_Req] means a numeric field with no allowable null values and a precision of 6.Item must always be populated with a value.
[SmallInteger; Yes; 4; Pop_Req] means a numeric field, with allowable null values and a precision of 4.Item must always be populated with a value.
[String; No; 1000; Pop_Req] means a character field, with no allowable null values and a length of 1000 characters available.Item must always be populated with a value.
In all of the above examples, the last entry was Pop_Req. This is one of numerous options for the status of required population of an item. The complete list and associated definitions are as below:
Pop_Req (Population Required): All features must have this item populated. If information is not available to complete this item's entries, either from the supplied base material/digital data or authorised source material, then an Action Request to GA should be generated.
Pop_Aut (Population Automatic):Population of this item is conducted by automatic means on entry to GA's NTDB. Producers should not alter or add or delete values within this item in any way during production processes without authorisation from GA.
Pop_Wk (Population Where Known):All features must have this item populated where information is available in either the supplied base material/digital data or authorised source material provided by GA. If information is not available no Action Request is required unless leaving the field blank would cause a logical inconsistency.
Pop_Dep (Population Dependant): Population of this item, for each feature type, is dependant on specific rules within the brief description following the data type entry.
Planimetric & Elevation accuracy is given in metres. Section 1 Chapter 3.7 Positional Accuracy describes how to define the values for planimetric and elevation accuracies. In additional it sets out in Chapter 3.7.6 the minimum acceptable planimetric and elevation accuracies based on scale and feature type and when an accuracy requirement is not stated in work instructions this is the minimum planimetric and elevation accuracy that must be met for capture of a feature. If a feature's capture just meets these accuracies, those values stated in Chapter 3.7.6 should be used to populate these fields. However where features are captured more precisely than the minimum planimetric and elevation accuracies stated in the specifications this may be indicated by a more reflective value entered into the relevant field. (e.g. The planimetric accuracy for road in the specifications is stated as 100m at 1:250 000 but a road was captured to within 20m of its centreline position on imagery. The imagery has a known ground control error of 15m and therefore the roads is within a maximum of 35m of its ground position. The value of 35 may be used in the planimetric accuracy field, for that feature, in precedence to the value of 100. ) (see Section 1 3.7 Positional Accuracy and Section 1 3.6 Feature Level Metadata for more information) |
| Geodatabase Rules |
The geodatabase rules section includes any additional selection criteria and any other notes on usage which apply to the inclusion/capture/attribution of the feature type data entry into the applicable geodatabase.
This section will be split into a maximum of 4 main categories under the headings '1:25 000', '1:100 000', '1:250 000' and 'General - All Scales'. Rules situated under the headings '1:25 000', '1:100 000' and '1:250 000' will be specific to that scale and when no rules apply to a specified scale that heading will not be shown. Rule situated under the heading 'General - All Scales' will apply to all scales listed for that feature type.
This section will be blank if there are no specific notes not covered by other sections. |
| Inter-Feature Relationship Rules - Internal to Associated Dataset |
The section specifies relationships between the designated feature type and other feature type entities within the same dataset.
This section will be split into a maximum of 4 main categories under the headings '1:25 000', '1:100 000', '1:250 000' and 'General - All Scales'. Rules situated under the headings '1:25 000', '1:100 000' and '1:250 000' will be specific to that scale and when no rules apply to a specified scale that heading will not be shown. Rule situated under the heading 'General - All Scales' will apply to all scales listed for that feature type.
This section will be blank if there are no specific notes not covered by other sections. |
| Inter-Feature Relationship Rules - External to Associated Dataset |
The section specifies relationships between the designated feature type and other feature type entities not within the same dataset.
This section will be split into a maximum of 4 main categories under the headings '1:25 000', '1:100 000', '1:250 000' and 'General - All Scales'. Rules situated under the headings '1:25 000', '1:100 000' and '1:250 000' will be specific to that scale and when no rules apply to a specified scale that heading will not be shown. Rule situated under the heading 'General - All Scales' will apply to all scales listed for that feature type.
This section will be blank if there are no specific notes not covered by other sections. |
| Map Rules |
The map section gives information specific to the use of the feature type on the map. This section will be blank if there are no specific notes or when information from the feature type is not used on the map. Map rules do not influence how information is to be captured within the geodatabases.
This section will be split into a maximum of 4 main categories under the headings '1:25 000', '1:100 000', '1:250 000' and 'General - All Scales'. Rules situated under the headings '1:25 000', '1:100 000' and '1:250 000' will be specific to that scale and when no rules apply to a specified scale that heading will not be shown. Rule situated under the heading 'General - All Scales' will apply to all scales listed for that feature type.
This section will be blank if there are no specific notes not covered by other sections. |
| Related features |
Feature types which have a relationship with this feature type.
When all feature types in a single feature class have a relationship with the designated feature type, the feature class may be specified instead of the individual types but in this case it will be noted as such. E.g WaterbodyBoundaries (Feature Class). |
| Related chapters |
Chapters in the specification which include information relevant to this feature type. |
| Related Products |
Products produced by GEOSCIENCE AUSTRALIA which may use the feature type. E.g. 'GEODATA TOPO250K'. This may provide useful information if Geoscience request data maintainence based around a product release. |
| Note |
Additional Note, generally a disclaimer of some kind. |
3. Sample Entry
| Scales |
1:250 000
&
1:100 000
|
Feature Type
Feature Class
Feature Dataset
Geometry Type
Definition
Minimum Size Criteria
| Minimum Size for: |
Criterion |
1:25 000 |
1:100 000 |
1:250 000 |
| Inclusion |
Area (sq m) |
|
|
|
| Inclusion |
Length (m) |
125 |
125 |
1250 |
Data Capture and
Map Representation |
Area (sq m) |
|
|
|
Data Capture and
Map Representation |
Length (m) |
125 |
500 |
1250 |
Data Attributes
Examples:
CLASSIFICATION (CLASS) [String;Yes(No);40;0;0;Pop_Req] The entities classification or status;
Acceptable Domain Entries from dm_RoadClassification at 25K and 100K as well as acceptable entries for the 250K field;
Dual Carriageway
Principal Road
Secondary Road
Minor Road
Track - 250K only
Vehicular Track - 25K and 100K only
NATIONAL ROUTE NUMBER (NRN) [String;Yes;12;0;0;Pop_Wk] The national route number/s assigned to the road ( if multiple numbers, delimited by a minus sign). Alpha characters in this field are to be in upper case.
FEATURE RELIABILITY DATE (FEATURERELIABILITY) [Date;Yes;36;0;0;Pop_Req] The reliability date of the spatial object; Date to be adjusted only during spatial change or verification of an existing feature location or the capture of a new feature (see Section 1 Chapter 3.6);
Most Recent Reliability Date of Revision Source Material (or Base Material/digitial data for inital capture) used for Spatial Verification
PLANIMETRIC ACCURACY (PLANIMETRICACCURACY) [SmallInteger;Yes(No);0;4;0;Pop_Req] The standard deviation of the horizontal positional accuracy.
FEATURE WIDTH (FEATUREWIDTH) [Double;Yes;0;8;4;Pop_Dep]
Feature width is only used for roads under construction (symbol 252). All other roads will have a feature width of '0'. The width of symbol 252 reflects the road classification, the following values will be used:
Feature width; Road class;
0.9 - Dual carriageway
0.9 - Principal road
0.6 - Secondary road
0.4 - Minor road
Geodatabase Rules
Examples:
1:25 000
Size and any other selection criteria apply to all feature occurances. Roads less than 200m will not be captured where they lead to a building, are a circular driveway or end between closely spaced buildings.
1:100 000
Size and any other selection criteria apply to all feature occurrences. An exception will be minor roads in built up areas which will be treated as per the rules stated in Inter-Feature Relationship Rules - External.
Minor roads and vehicular tracks will be named where named on the base material/digital data (e.g. state mapping source) unless there is clear evidence they no longer exist. New names for Minor roads and vehicular tracks will be added where named on road revision source material supplied.
1:250 000
Size and any other selection criteria apply to new feature occurrences. All feature occurrences existing in the TOPO250K NTDB will be retained unless there is clear evidence they no longer exist. An exception will be minor roads in built up areas which will be treated as per the rules stated in Inter-Feature Relationship Rules - External.
Minor roads and vehicular tracks will be named where named on the default version of the TOPO250K geodatabase unless there is clear evidence they no longer exist. No new names for Minor roads and vehicular tracks will be added in densely settled regions as defined by Appendix C. New names for Minor roads and vehicular tracks will be added in sparsely settled regions as defined by Appendix C where named on road revision source material supplied. A selection of new names for Minor roads and vehicular tracks may be added in moderately settled regions as defined by Appendix C, these should be taken from the roads revision source material supplied. In moderately settled regions preference should be given to minor roads and vehicular tracks which consititute through routes and/or lead to cultural or natural features.
General - All Scales
Road classifications will be as shown on the roads revision source material supplied.
Classifications are:
Dual carriageway - Divided Highway, Freeway, Tollway, or other major roads with separated carriageways in opposite directions.
Principal Road: - Highways, major through routes and major connecting roads.
Secondary road: - Connecting roads that provide a connection between major through routes and/or major connecting roads, or connections between regional centres.
Minor road: - All other roads which form part of the public roads system between Principal roads and Secondary roads.
Vehicle tracks: - Public or private roadways of minimum or no construction which are not necessarily maintained.
Roads with a formation 'Unknown' should be symbolised as if the formation was 'Unsealed'. Only Secondary and Minor roads will be subject to the formation 'Unknown'. The practice of applying the 'Unknown' formation to roads should be limited to exceptional circumstances.
Roads identified by GEOSCIENCE AUSTRALIA to be captured in the geodatabase but not displayed on the map face due to security or sensitivity reasons will be given the symbol number '0'.
Inter-Feature Relationship Rules - Internal to Associated Dataset
Examples:
General - All Scales
Roads will have nodes at all intersections.
Where the foot track is associated with or uses a section of road it should be made coincident with that portion of the road. A vertex on the road should exist at the exact location of the entry and exit points of the foot track.
Inter-Feature Relationship Rules - External to Associated Dataset
Examples:
1:100 000
Minor roads entering a builtup area will be continued to the first intersection with a major through route (preference should be given to intersections with dual carriageways, principal or secondary roads). In addition, sufficient minor roads will be shown to reflect the Built-up Area's road pattern. Select the major through routes (from Primary Reference material) to reflect the road pattern within the area whilst avoiding clutter. This rule will also extend to other features (including defined holes, areas of universe polygon) in the built-up area layer where they are surrounded by a built- up area. See Section 3 Chapter 6.7.3.
1:250 000
Mnor roads entering a builtup area will be continued to the first intersection with a dual carriageway, principal or secondary road. Minor roads totally contained in built-up areas will not be shown. This rule extends to other features (including defined holes, areas of universe polygon) in the built-up area layer where they are surrounded by a built-up area. See Section 3 Chapter 6.7.3.
General - All Scales
Roads cannot overlap;
Sea, Flood Irrigation Storage, Town Rural Storage, Lake perennial, Canal Areas, Watercourse Area perennial.
Roads cannot intersect;
Cliff, Cutting, Razorback and Embankment.
For detailed rules regarding situations involving roads, vehicle tracks, fences and vermin proof fences please refer to the Fence feature type in Appendix A.
All dual carriageways, principal and secondary roads will be shown including those in built-up areas.
Map Rules
Examples:
General - All Scales
All dual carriageways, principal & secondary roads will be named where name is known.
Roads under construction will be labelled 'under construction'.
Roads whose position is questionable will be labelled 'position approximate'.
Related Features
Examples:
Built Up Area, Cemetery Area, RecreationAreas (Feature Class), Ferry Route Line, Ford Line, Ford Point, Gate, Distance Indicator, Gorge, Pass, Road Junction, Place Name, Populated Place
Related Chapters
Examples:
Section 2 chapter 2.2.3
Section 3 chapters 3.2.4, 5.8, 5.11.2, 6.5.3 and 6.7
Appendix C
Related Products
GEODATA LITE TOPO100K, GEODATA TOPO250K, NTMS 100K, NTMS 250K
Note: See disclaimer in Appendix A Chapter 1.2 Use of Feature Type Dictionary - Structure of an Entry regarding Related features,chapters & products.
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