what size of historical AIS files should be expected
AIS History File Sizes
Spire Maritime provide historical AIS in the file format documented here https://faq.spire.com/spire-maritime-ais-data-sample-standard-format
It is a per message format.
To estimate file sizes for provision of historical AIS data we need to know the period and the sources of AIS being provided.,
As of 2021-08-30 1 day of satellite and terrestrial AIS, with down sampled terrestrial AIS created a set of data files that when compresses were 34Gb in size. Dynamic AIS would add about 12.5% creating a daily file archive of approximately 38Gb.
The system used to spool historical AIS files chunks requested data into multiple files, normally about 300mb in size. So as well as the total file size, the number of files received will be determined by the size of the AIS history provided.
AIS History File Delivery
Unless a small sample is requested that can be delivered by E-mail then AIS history files are provided through a Google Cloud Storage (GCS) bucket. Access to GCS requires a google managed account that can be granted access to the bucket and it is advised to use the Google Cloud SDK to download the files.