Quick Guide to get information and data via direct HTTP access

In this section there are several examples and explanation about how to query and download the data from the different investigations.

As aforementioned, note that within the HTTP QUERY parameter a ADQL language is used (similar to SQL), and is using URL enconding.
Remember that you will need to log in before download the data (see Authentication section).


Which are the 'Datasets' per Investigation

Search for investigation_unique_acronym within the view 'Datasets', where investigation='DCMIX-2'. The products will The results will come in JSON format: 


https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=json&QUERY=SELECT+dataset_name,dataset_unique_acronym,dataset_description,start_date,end_date,prior_access_initial_date,prior_access_end_date+from+hreda.v_dataset+where+investigation_name='DCMIX-2'

Note that some datasets could be restricted depending on the prior access period and security level.


Which are the 'Product Types' per 'Investigation'

Search for product_type and investigation_name within the view 'File Metadata'.
The results will come in CSV format: 


https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=SELECT+DISTINCT+investigation_name,product_type+from+hreda.v_file_metadata+order+by+investigation_name,product_type

The previous query provides all product types for all investigations. To show the product types for a given investigation, the query is actually very similar. Here we provide an example using the 'DCMIX-2' investigation: 


https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=SELECT+DISTINCT+investigation_name,product_type+from+hreda.v_file_metadata+where+investigation_name='DCMIX-2'+order+by+product_type

Download products from a given Investigation and a 'Product Type'

Search for file_path and file_name within the view 'File Metadata', where investigation='DCMIX-2' and product type name contains 'table'. The products will be downloaded in a compressed file (TAR.GZ): 


https://hreda.esac.esa.int/hreda-sl-tap/data?retrieval_type=PRODUCT&QUERY=SELECT+file_path,file_name+from+hreda.v_file_metadata+WHERE+investigation_name='DCMIX-2'+AND+product_type+LIKE+'%25table%25'&compress=true

Note that this url requieres a Log In


Download products from a given Investigation and Date

Search for file_path and file_name within the view 'File Metadata', where investigation='DCMIX-2' and date is after '2014-02-05 10:00:00'. The products will be downloaded in a compressed file (TAR.GZ): 


https://hreda.esac.esa.int/hreda-sl-tap/data?retrieval_type=PRODUCT&QUERY=SELECT+file_path,file_name+from+hreda.v_file_metadata+WHERE+investigation_name='DCMIX-2'+AND+acquisition_time>='2013-12-02 18:15:12.000000'&compress=true
Show custom filters for each investigation

For each investigation, there may be some parameters that are used as search criteria inside the investigation. These values are specific depending on the investigation. In order to search for the list of them: 


https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=json&QUERY=SELECT+DISTINCT+investigation_name,filter_name+from+hreda.v_investigation_filter+order+by+investigation_name
Show relevant search criteria identified by investigation

For each investigation some parameters (investigation specific and non-specific) have been identified for being used as search criteria for filtering investigation products. Below, the query for retrieving those investigation filters as well as the value interval that they may take if applicable, is displayed: 


        https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=SELECT+investigation_id,investigation_name,filter_name,filter_type,specific_filter,metadata_field,column_file_metadata,first_date,last_date,min_number,max_number,values_enumeration+FROM+hreda.v_investigtion_filter+order+by+investigation_id

Search filtering by the specific metadata for each instrument

For each investigation we can search based on the specific metadata. Take in account, that the field can not be accessed directly, and you will need to use specific functions depending on the data type. To see the data time, you can use the previous query

Here there is one example for the runName: 

https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=SELECT+DISTINCT+file_name,file_path+from+hreda.v_file_metadata+WHERE+extract_json_text(specific_metadata,'runName')='2 '+AND+investigation_name='DCMIX-2'

In order to increase performance, it will be useful to use the filter specific metadata is not null, as in the example:


https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=SELECT+DISTINCT+file_name,file_path+from+hreda.v_file_metadata+WHERE+specific_metadata+is+not+null+and+extract_json_text(specific_metadata,'runName')='2'+AND+investigation_name='DCMIX-2'

Get information about the specific metadata for a given investigation

For each investigation we can select information of the specific metadata. Take in account, that information is split in two fields: specific_metadata that allow filtering and extra_information that does not allow the filtering. Here there is one example for DCMIX3 data: 


https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=SELECT+DISTINCT+investigation_name+file_name,file_path,specific_metadata,extra_information+from+hreda.v_file_metadata+WHERE+investigation_name='DCMIX-3'

Get number of Blank Books for a investigation

For each investigation it is possible to get the number available Blank Book providing product_type='Investigation Data Blank Book' and the desired investigation thought the investigation_name Here there is one example for DCMIX4 data: 


https://hreda.esac.esa.int/hreda-sl-tap/tap/sync?REQUEST=doQuery&LANG=ADQL&FORMAT=csv&QUERY=SELECT+COUNT+(file_name)+from+hreda.v_file_metadata+WHERE+investigation_name='DCMIX-4'+AND+product_type='Investigation Data Blank Book'

Download available Blank Books for a investigation

For each investigation it is possible to download the available Blank Book providing product_type='Investigation Data Blank Book' and the desired investigation thought the investigation_name Here there is one example for DCMIX4 data: 


https://hreda.esac.esa.int/hreda-sl-tap/data?retrieval_type=PRODUCT&QUERY=SELECT+file_path,file_name+from+hreda.v_file_metadata+WHERE+investigation_name='DCMIX-4'+AND+product_type='Investigation Data Blank Book'&compress=true

Download the last Blank Book for a investigation

For each investigation it is possible to download the last Blank Book providing product_type='Investigation Data Blank Book', the and the desired investigation thought the investigation_name Here there is one example for DCMIX4 data: 


https://hreda.esac.esa.int/hreda-sl-tap/data?retrieval_type=blankbook&QUERY=SELECT+file_path,file_name+from+hreda.v_file_metadata+WHERE+investigation_name='DCMIX-4'+AND+product_type='Investigation Data Blank Book'