Copyright 2013
Meier IT Pty Ltd
QLD Australia
Disclaimer


GDA Converter is the program that is comprised of three utilities:

1. Converting MapInfo files to GDA,
2. Converting MapInfo tables from GDA to AGD66 or AGD66 and,
3. Converting coordinates stored in columns to GDA.

Converting MapInfo files to GDA

The process to convert files to GDA is to build a list of files that require conversion by selecting files or folders through an input form. By selecting the "Convert" button all files in the list passing the checks are converted. After the conversion, a list reporting the outcome for each file (converted or not converted) is presented through the output form.

The Input Form

The concept of the input form is to build up a list of MapInfo files that are to be converted to a GDA coordinate system. Files can be added by clicking the "Add File/s" button which will provide a dialogue where files can be selected to add to the list (see screen example below).


If an entire folder of files is required to be included in the list, click on the "Add Folder" (see screen example below). A folder or drive can be selected and all of its subdirectories will then be searched for MapInfo tables, workspaces or geosets.


Records in the GDA conversion list can be sorted by clicking on the column headers.

After files have been added to the GDA conversion list, the GDA Converter checks whether each file needs converting. For example, the file will not be converted if it already in GDA format or the file is in a read only state. Click here for preconversion checks performed by the software prior to converting each file to the GDA coordinate system. The Convert column will be ticked only if the file is able to be converted.

Output Form

After the files have been processed, a report is produced displaying the outcome of the attempted conversion to the GDA coordinate system for each file. Files which were not able to be converted to the GDA coordinate system will result in an error code and message.

Use the "Copy to Clipboard" button to transfer the list to your clipboard so that it can be pasted into other applications such as a spreadsheet.

To produce a hard copy report, use the "Print Preview" button so that list can be sent to a printer. There are a host of settings within the print preview that can be used to format the report.


Options

The GDA Converter software provides backup and processing options, allowing customisation to suit user needs (see screen example below).


Backup Options

GDA Converter works directly on the MapInfo table and copies the original to a backup folder. Only the originals of successfully converted files only are placed in the backup folder. Any other files will remain untouched and left in their original locations.

The original files may be placed in the backup directory according to 3 possible naming options:

1. Files are placed directly under the backup folder. There is a risk using this option if two files with the same name but in different folders are converted that one will wipe over the other.

2. Files are placed in the backup directory under a directory called the same name as your user logon. There is a risk using this option if two files with the same name and logon account but in different folders are converted that one will wipe over the other.

3. Files are placed under the backup directory in a folder with the same name as the original. For example, if the original folder and file was c:\data\example.tab and the backup directory c:\temp, the backup file will be called c:\temp\data\example.tab. There is a risk that if a file is converted with the same folder and name but on a different drive that they could override each other. The chances of this loss occurring would usually be low, consequently it is recommended that this be the preferred backup option.

The "Overwrite" checkbox safeguards any files that may already exist in the backup directory with the same name as the file being converted. By ticking this option, the file will not be converted and an appropriate error will be recorded in the output.

Process Options

GDA Converter provides the following processing options:


Conversion of unprojected latitude and longitude files. The default MapInfo projection is unprojected latitude and longitude. You can use the conversion of unprojected latitude and longitude files option to assume these coordinates are on the AGD84 or AGD66 datum.
Conversion of tables in workspaces to GDA projection when the workspace or geoset is converted.
Conversion of tables referenced by seamless tables when selecting seamless tables for conversion to the GDA coordinate system.
Add a metadata tag to the converted MapInfo table. The tag name is called "GDA Conversion" and the date, time and username is recorded.

Converting tables from GDA to AGD66 or AGD84

This process is very similar to converting tables to GDA as described above however instead of converting tables to GDA it will convert them back to AGD66 or AGD84.


Converting coordinates stored in columns to GDA

Use the GDA Columns command to convert coordinates stored in columns in a MapInfo table to GDA coordinates. Select an open MapInfo table from the list and the projection you require it to be converted from. Also choose the columns where the coordinates are stored.

When using this command, the coordinates in the table are updated directly without saving. Use the standard save command in MapInfo to keep the changes.