How to use the HAIO

HAIO (Herschel Science Archive Inter-Operability Subsystem) is a complementary way to access the Herschel Science Archive (HSA) content through HTTP access. This subsystem shares the core system of the standard HSA User Interface. It is normally called using scripts, application code or command line tools.

Capabilities:

• Observation Retrieval: It allows the user to obtain one single observation file.
  
• Product Retrieval: It allows the user to obtain the products associated to a determinate observation.
  
• Observation / Product Search: It allows the user to discover observations or products that fulfill a certain search criteria.
  
• Multiple Observation / Products Search / Retrieval: By combining the two previous points, the HAIO allows the
  download of all the observations or all products, that fulfill a certain search criteria, by using pagination internally.

This interface is ideally created to fulfill the necessity of retrieving data massively. Through it you can retrieve either one or all the observation or product files that match a given criteria (HCSS_URN, OD_NUMBER, HCSS_CLASS_TYPE, etc).

HAIO Requests

HAIO accepts two kinds of requests:

Table 1: Type of HAIO requests

Request type	Description	Syntax
Metadata Request	To be used when we want to retrieve the metadata details of observation file(s)	http://archives.esac.esa.int/hsa/aio/metadata.jsp?
Data Request	To be used when we want to retrieve an observation file	http://archives.esac.esa.int/hsa/aio/product.jsp?

Ideally, this interface should be used by an application that retrieves a list of observations through a metadata request, and then issues a data request for each one of them in order to retrieve the files. An example of software application that uses this interface is HIPE (Herschel Interactive Processing Environment), which can be downloaded from here.