Thanks Frank, for your response. I have uploaded a patch for isi2dataset.cpp http://gdal.googlegroups.com/web/isis2dataset.patch this patch add new functionalities : detached dataset with using the pointer object key : ^QUBE = "data.xxx" ^QUBE = ("data.xxx") ^QUBE = ("data.xxx", nnn) ^QUBE = ("data.xxx", nnn <BYTES>) regards