Four organization units initially comprised PAGASA. The National Weather Service undertakes the preparation and subsequent prompt issuance of forecasts and warnings of weather and flood conditions. The National Atmospheric, Geophysical and Astronomical Data Service undertakes the acquisition, collection, quality control, processing, and archiving of atmospheric and allied data. The National Geophysical and Astronomical Service undertakes observations and studies of seismological and astronomical phenomena, as well as provides the official time for the country. The National Institute of Atmospheric, Geophysical and Astronomical Sciences is responsible for the training of scientists and technical personnel with respect to atmospheric, geophysical and astronomical sciences. Later on in 1977, the Typhoon Moderation Research and Development Office and the National Flood Forecasting Office were placed under administrative supervision of PAGASA, pursuant to Presidential Decree No. 1149, s. 1977.