Opening of full orbits of MERIS or AATSR data files are opened by applications (VISAT, MERCI) is sometimes time-consuming and users observe a considerable delay. This is possibly caused by the fact, that tie-point and other metadata data is read in entirely each time a product is opened. The opening of product files shall be as light-weight as possible thus lazy loading of data shall be deferred to the point in time when it is actually needed (lazy-loading).