Address Geocodification

The Address Geocodification analysis ("Address Matching") implemented in the SPRING is a common tool available in several GIS systems. The geocodification is a point identification process over a map based on the object attributes, for instance, streets in the SPRING network model. The address location is performed over an alphanumeric characters sequence (text strings), which can be broken into several components (street name, initial and last number, neighborhood, city, etc...), which are stored in fields in an object table.

One can imagine the geocodification as a simple pin placement in a paper map. The user has an address to be marked in a map, and the map has all streets of a city.

The address geocodification compares a certain address with addresses in the database, and then determine the best place over the map to mark the address (pin placement). Thus, the address database has to be prepared to perform the address comparison.

Each street block in a city must have basic information so the comparison can be executed. In the SPRING case, street name, initial number and last number are mandatory information for each block. So, using an interpolation process, the address position is estimated in a block and also the street side (left or right) where the mark will be placed.

A pair of coordinates will be created to show a point in the drawing window, which can be stored in a IL if you wish.

 E xecuting the address geocodification:

  • a network model IL, displaying all the streets;
  • each block of the street map has to be associated to a label/name of an object in the database;
  • this object has to have descriptive information (attributes) fundamental for constructing a comparison sequence. These are mandatory attributes: street name (TEXT type), initial number (INTEGER type) and last number (INTEGER type);
  • a search parameter, defined in another character sequence, which can be informed in three (3) ways:
    • by editing, informing one address at a time;
    • using a text file, having an address list to search;
    • by reading a DBF file , which has an address list (not implemented yet);
  • a hit % value selected - corresponding to a value (in percentage) of the proportion of hits found in the search sequence, when compared to the object sequence. This allows that more than one candidate shows up as an answer. Lower percentage values can take to situations where "Andrade Street", "Antonio Street" and "Antonieta Street" are eligible in a search for "Andrade de Souza Street". Higher percentage values constraint the candidates number for exactly the same comparison values.
  • an Offset (m) value can be selected - once the point is found in the map it is possible to inform the distance (to the left or to the right) where the mark will be placed (not implemented yet);
  • a thematic or cadastral category to store the points found.

The procedures for each search type are described next:

Executing geocodification by editing:

  • activate the IL of the network model in the "Control Panel";
  • click on Network - Address Geocoding... to open the corresponding window;
  • click in the Object Properties... button to associate the comparison parameters with the object attributes;
  • after defining the object parameters click on Edit for Search Parameters.
  • type in the Address, Number and Complement fields, the search address;
  • click on hit % and select the desired value. See the meaning of this button above;
  • click on Offset (m) and select the desired value. See the meaning of this button above;
  • click on the Calculate button to execute the address search. The points found are presented in the drawing window.
  • click on Clean Marks to cancel the points placed before applying again or save in an IL.
  • click on Category... and select either the thematic or the cadastral;
  • if the selected category is cadastral, click on Object... and select a database defined previously;
  • if the output category is cadastral, type in Label an identification for the point found;
  • type the IL name to be created;
  • if the output category is cadastral, it is possible to insert, besides the label/name, other attributes. In this case click on Insert DBF attributes to include the ADDRESS, NUMBER, COMPLEMENT, COORDX and COORDY in the object table;
  • click on the Execute button to save the points in the map.

NOTE : Other points can be searched and stored in the same IL, however, they have to have different labels for the same object category.




Executing geocodification using a text file:

  • activate the IL of the network model in the "Control Panel";
  • click on Network - Address Geocoding... to open the corresponding window;
  • click in the Object Properties... button to associate the comparison parameters with the object attributes;
  • after defining the object parameters click on Edit for Search Parameter.
  • click on Text File... to select a text file which has the search fields (see the text file syntax below);
  • click on hit % and select the desired value. See the meaning of this button above;
  • click on Offset (m) and select the desired value. See the meaning of this button above;
  • click on the Calculate button to execute the address search. The points found are presented in the drawing window.
  • click on Clean Marks to cancel the points placed before applying again or save in an IL.
  • click on Category... and select either the thematic or the cadastral;
  • if the selected category is cadastral, click on Object... and select a database defined previously;
  • if the output category is cadastral, type in Label an identification for the point found;
  • type the IL name to be created;
  • if the output category is cadastral, it is possible to insert, besides the label/name, other attributes. In this case click on Insert attributes to include the ADDRESS, NUMBER, COMPLEMENT, COORDX and COORDY in the object table;
  • click on the Execute button to save the points in the map.

NOTE: If the output IL is cadastral the object label and name will be the first column of the TXT file (see the syntax below).

TEXT FILE SYNTAX

Each line of the file corresponds to a search string. Each field has to be separated by a semi-colon (;). The first column has to be an unique address identification. If the complement is not filled, just type a semi-colon (;) after the third field. Schematically we have:

<label_add> ; <name_add> ; <number> ; <complements>
EMP00023 ; Santa Helena Street; 45 ;
EMP00022 ; Pedro Cardoso Street; 345; São Dimas




Executing geocodification by a DBF file: (not implemented yet )



See also:
Database Query
Controlling Objects Visualization.
Grouping Module.
Attributes Table.
Attributes Query.