.GAL is the extension used by GenePix to name files storing information about an array layout. The spot location and block layout is registered in this files.

Most often this information is also within GPR files so, in general, GPR are self sufficient. Thus, Babelomics should not need such layout information and indeed, GAL files cannot be used in Babelomics.

Hence, if your GPR files do not contain the array layout information you will not be able to normalize them using Babelomics normalization tools.