One of the new features in CoordTrans v2.0 is that you can manage a large database of grids and datums. This section shows how you can import, export, remove and create new grids that you can use in your conversions.

You can find the grid manager by clicking "Manage Grids" under the Tools-menu in the main display (see figure 1). This will show you a dialog similiar to the dialog where you select a grid for conversion, with the addition of some input fields. When you select a grid, the fields will be populated and you can edit the grid as you wish.

Figure 1 - finding the grid manager

Creating a grid

To create a new grid you can either create a new grid from scratch or clone an existing grid and use that as a base. To create a new grid from scratch, simple navigate to a region of your choice and right click an appropriate datum. This will display a menu with a single option "Add Grid". If you click a new grid will be created (see figure 2). To clone an existing grid, right click the grid and select "Clone". This will create an identical copy of the grid that you can change without altering the original grid.

Figure 2 - adding a grid

To alter a grid, first select it and then edit the parameters you whish to change. Once you are satisfied with the alteration, click "Save" to save the changes. Note that one grid can be associated with several regions! If you change the parameters of a grid, they will be applied to all regions. If you wish to make a change specific to a region, clone the grid and change that instead.

To remove a grid, simply right click it and select remove. If you click remove while a region is selected, the grid will simply be dissassociated with the selected region. However, if you remove a grid that you have found through the search box, or if you remove a grid that is available under the "Unspecified" category, the grid will be removed completely from the database.

Figure 3 - removing a grid

If you wish your grid to be accessible in another region, just drag the grid from the grid list and drop it on the region in which it should be accessible. This will associate the grid with a new region, i.e. if you change the grid in one region, it will change in the other as well.

If you create or alter grids you can save the grids into a file that can be imported into CoordTrans. Thus, it is possible to e.g. make backups of the grids you create or send grids between computers. To export a grid, simple right click it and choose export (See figure 4). If you want several grids in one file, choose an existing file and then choose merge. This will add the grid to the file instead of e.g. overwriting it. By doing this, you can maintain your own database of grids that you can distribute. When you import a grid, the grid will be compared to those in the database. If the grid being imported already exists, it will be compared to the existing. You can then choose to ignore the grid or overwrite the existing grid.

Figure 4 - exporting a grid

If you don't know where your grid is, you can always search for it in the find-box (see figure 5). To search for a grid, simple enter part of its name, its ESRI number, the datum it is based on, a zone etc to search through the database. Note that when you search for a grid, you don't associate the selection with a region. This means that if you remove a grid you have found from a search, it will be completely removed from the database.

Figure 5 - searching the database for a grid