ASCII - SPRING Format
The proposal to use the ASCII format as a standard for SPRING is the
same as the other software: it turns the cartographic data exchanging process simple,
allowing each user to prepare its own data in this format and the companies
representing the different systems to quickly write conversion routines.
The main characteristics of the ASCII/INPE format are:
- legibility, allowing access to external edition.
- independency of the internal representation for each machine.
- flexibility, allowing addition of new fields as a function of requirements.
A set of geographic data in the proposed pattern is materialized as a file set
coded in ASCII, where each file stores an entity type (points, lines and 3D lines
etc). The information is stored in a sequential pattern and divided into lines
of variable size bounded by Carriage Return followed by Line Feed.
Multiple blanks and special characters such as Carriage Return and Tabs
are equivalent to a single blank. There is no constraint related to the line length.
Keywords allow to identify easily, several data types and format components. It was
used, as keywords, terms from the english vocabulary, which are used in Brazil as
common sense in order to facilitate the information exchange with international organizations.
Each ASCII file is divided into 3 sections: Identification (formed by a
keyword identifying one of the modeled entities by the pattern), Information
(section of variable size having the relevant information for the user about the data) and
Data (section formed by data and specific attributes). See, next, each of them.
Learn more about Import/Export in SPRING
How to import or export ASCII data.
Identification
This section has to be at the beginning of the file, and has to be formed by one of
the keywords that identifies one of the supported entities by the pattern. For this
section the following keywords are defined:
- LINES: data as lines without topology. These lines can be used to form polygons (closed areas, as
for instance, urban maps) or open lines (for instance, a map with rivers from a region)
- POINTS: points file ("label points") used for polygons or lines labeling, in case
a polygon internal point or any point in a line;
- POINT2D: point entity and its identification (label, name and
object for cadastral points or class for thematic);
- SAMPLE: sample of points in space, used as input for terrain numerical models. An entity
file of the SAMPLES type might have either height spots (indicated by the
keyword POINT3D or contour lines (indicated by the LINE3D keyword);
- GRIDREG: files having a regular grid, used as input for the
terrain numerical models;
- TABLE: files having tables, used to store descriptive attributes for
geographic objects;
- TEXT: files having texts, used to give toponomy to any data model
in SPRING;
- POLYGONS: polygons file where each one is exported as an island. There
is line duplicity that make boundary between two polygons. If it is imported to SPRING, the duplicity must be removed;
- NETWORK: file of oriented lines in the network model. Each line has an identifier,
impedance and demands;
- NETWORK_OBJECTS: points file ("label points") used to label
lines and nodes in an IL in the network model. To differentiate the line identification
and nodes the keywords LINES and NODES are used, respectively.
Information
Located after the Identification of the entity type, this section is bounded
by the keywords: INFO and INFO_END. This section is optional, but
highly recommended in the files, because it has important information for the user
about the data and, perhaps, for an analyst who wants to design a routine to
read the data. This section has a variable size and it is composed by lines, the
beginning of each line is identified by a keyword available for this section. For the
Information section the following keywords are defined:
- INFO: Indicates the beginning of the Information section.
- INFO_END: Indicates the end of the Information section.
- DATUM: Earth model used in the projection and corresponding parameters,
presenting the following order, and separated by commas: name, semi-major axis or
radius,
flattening, ellipsoids displacement in the x, y and z directions.
- PROJECTION: Data projection, and corresponding parameters presented in the
following order and separated by commas: projection name, hemisphere, latitude origin,
longitude origin, first parallel and second parallel. Notice that depending on the
projection some parameters are not required, so these parameters will not be present, but
their commas should be kept.
- BOX: Project involving rectangle.
- UNITS: Unit system for data and parameters.
- SCALE: Data scale.
- GRIDDEF: Parameters definition in a regular grid.
- SEPARATOR: Option to control the way entity data is stored TABLE,
POINTS or POINT2D.
- FORMATED: Defines the fields formatting for an entity TABLE (NOT IMPLEMENTED).
- UNFORMATED: Option to control the way a TABLE entity data is stored.
It is used with the SEPARATOR item.
- DATABASE: Name for the database that has the original data
- CATEGORY_OBJ: Name for the objects category in the database, used for tables.
- CATEGORY_NOSPATIAL: Name for the Non_Spatial category in the database, used for descriptive tables.
- T_KEY: Object label definition in an attributes' table.
- T_NAME: Object name definition in an attributes' table.
General comments about the data can be inserted in this section, just initialize the line using
two bars (//). There is no limitations related to the size a comment might have.
Example:
TABLE
INFO
// Attributes table
// ASCII file generated by SPRING System
// Project: Brasilia - Information Layer: Blocks_Map
// Category: Urban_cadastre - Model: CADASTRALMODEL
DATUM SAD69, 6378160.000000, 0.003353, 0.000000, 0.000000, 0.000000
PROJECTION UTM/SAD69, 1, 0.000000, -0.785398, 0.000000, 0.000000
BOX 183557.000000, 8246273.000000, 195009.000000, 8258937.000000
UNITS Meters
SCALE 25000.000000
SEPARATOR ,
UNFORMATED
DATABASE DF
CATEGORY_OBJ Blocks
T_KEY , TEXT , 32 , 0
T_NAME , TEXT , 32 , 0
ASA , TEXT , 7 , 0
USO , TEXT , 15 , 0
NUM_IMOVEL , INTEGER , 10 , 0
POPULATION , INTEGER , 10 , 0
RENDA , REAL , 17 , 8
INFO_END
SQN-102 , SQN-102 , NORTH , Hotels , 12 , 3500 , 17000.000000
SQN-103 , SQN-103 , NORTH , Public , 15 , 250 , 20000.000000
SQN-104 , SQN-104 , NORTH , Public , 18 , 300 , 25000.000000
SQN-105 , SQN-105 , NORTH , Public , 100 , 400 , 30000.000000
END
NOTE: This section can be formatted only by comments, comments plus some
keywords or comments plus all keywords available for this section.
Data
This section starts after the keyword INFO_END and it is composed by one or more
entity instances defined in the section Identification. At the end of each entity,
in case of lines or contour lines it is delimited by the keyword
END, and the end of the data in the file by the sequence END END. The
other entities (points, samples, grid, table and texts) use only an
END at the end of file.
The data can be declared in plane coordinates (meters, kilometers, millimeters, feet or inches),
or geographic coordinates (decimal degree, decimal second or latitude/longitude).
When the file is in geographic coordinates; latitude and longitude, the following
conventions are used:
- In front of the latitude values the letters S, s, N or n should appear.
- In front of the longitude values one of the letters W, w, E or e should appear.
Example: s 23 13 38.6 w 45 53 51.0 or
w 45 53 51.0 s 23 13 38.6
IMPORTANT: The Spring exports in geographic coordinates, always in the Longitude / Latitude
order. However, when importing, the system recognizes also the coordinates pair in the
inverted form (Latitude / Longitude) as shown in the example above.
When the file is in geographic coordinates; decimal degree or second degree, the following
conventions are used:
- In front of the longitude/latitude value (in this order), use a negative symbol
(-) to indicate to the left of the 0 degrees meridian and in the south hemisphere.
Example -63.47887039 2.18374274
For alphanumerical data, that is, attributes' table, each line represents a register
and each field is separated by the character defined in the information section,
followed by the keyword SEPARATOR.
See the formats for each type of ASCII file defined in the identification section, that
is;
LINES
(lines without topology), POINTS (Identifiers),
POINT2D (thematic or cadastral points),
SAMPLE (terrain models),
GRIDREG
(regular grids), TABLE (descriptive attributes tables),
TEXT
(texts), POLYGONS (polygons as islands),
NETWORK
(oriented lines), NETWORK_OBJECTS
lines and networks nodes identification).
Notice that the file sections are always in the sequence:Identification,
Information, Data, where the Information section is optional, in most files.
ASCII Files and Models
To better understand the utility for each one of the ASCII file types and the data
model they belong to in SPRING, see the table below.
MODEL |
FILES/ EXTENSIONS |
NOTE |
Thematic
Points |
POINT2D/ *_P2D.spr |
Points representation (coord. X/Y) and class identification in the same file. |
Thematic
Lines and Polygons |
LINES / *_L2D.spr
POINTS / *_LAB.spr
POLYGONS/ *_POL.spr |
To get a thematic map in SPRING the LINES and POINTS files are enough,
because the first represents the lines/polygons and the second thematic classes identifications.
Remember to adjust and make polygons before importing a file POINTS, when the map has
polygons. The file POLYGONS is created only when exported, in case it has to be imported
it is recommended to remove duplicated lines among neighbor polygons. |
Cadastral
Points |
POINT2D/ *_P2D.spr |
Points representation (coord. X/Y), object identification
(Label and Name) and corresponding object category. |
Cadastral
Lines and Polygons |
LINES / *_L2D.spr
POINTS / *_LAB.spr
POLYGONS/ *_POL.spr |
To have a cadastral map in SPRING it is enough to
have the LINES and POINTS files. The first represent the lines/polygons and the second
objects identifications. Remember to adjust and make polygons before importing a POINTS file,
if the map has polygons. The file POLYGONS is created only when exported, in case it has to be imported
it is recommended to remove duplicated lines among neighbor polygons.
|
Numerical
Samples, Rectangular Grids, and Breaking Lines |
SAMPLE / *_L3D.spr
GRIDREG / *_GRR.spr
LINES / *_L2D.spr |
The files SAMPLE and GRIDREG are imported and exported
independently one from another. The breaking lines, which are 2D lines, are exported
as LINES, in case they are in the same sample file. However, a LINES file, can only
be imported for a thematic or cadastral if it will be used as breaking lines.
|
Networks
Lines and Nodes |
NETWORK / *_NET.spr
NETWORK_OBJECTS / *_NETOBJ.spr |
Both files have always to be together, but must be
imported separately.
|
All
Texts |
TEXT / *_TEX.spr |
A TEXT file can be used by any data model in SPRING, including images.
|
Objects
Attributes |
TABLE / *_TAB.spr |
An object table can be associated to an IL of any
cadastral category (point entities, lines or polygons), or networks (oriented lines
and nodes). Remember that internally the keyword CATEGORY_OBJ has
to be present. |
Non-spatial
Attributes |
TABLE / *.TAB.spr |
A Non-spatial attributes table might exist in a
database and at any time it can be connected to an object table for consulting. Remember
that internally the keyword CATEGORY_NONSPATIAL has to be present. |
See about Import/Export in SPRING
See also:
How to IMPORT data?
How to IMPORT data in the SGI?
How to IMPORT GRIB images?
How to EXPORT data?
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