cso_pal module

The cso_pal module provides classes for accessing data from the Product Algorithm Laboratory.

Data is available from a special portal: S5P-PAL Data Portal.

To browse through the data, use the browser interface.

PAL API

See the PAL API info for latest info.

S5P-PAL product files can be selected and downloaded using the Spatio Temporal Asset Catalog (STAC). The PySTAC Python interface is used for access.

Class hierchy

The classes and are defined according to the following hierchy:

Classes

class cso_pal.CSO_PAL_Inquire(rcfile, rcbase='', env={}, indent='')

Bases: UtopyaRc

Inquire available Sentinel data from the Product Algorithm Laboratory.

A query is sent to search for products that are available for a certain time and overlap with a specified region. The result is a list with orbit files and instructions on how to download them.

In the settings, specify the url of the portal:

<rcbase>.url              :  https://data-portal.s5p-pal.com/api/s5p-l2/collection.json

Specify the time range over which files should be downloaded:

<rcbase>.timerange.start  :  2018-07-01 00:00
<rcbase>.timerange.end    :  2018-07-01 23:59

Provide a product type:

! product type (always 10 characters!):
<rcbase>.producttype            :  L2__NO2___

Eventually specify a target area, only orbits with some pixels within the defined box will be downloaded:

! target area, leave empty for globe; format:  west,south:east,north
<rcbase>.area             :
!<rcbase>.area             :  -30,30:35,76

Name of output csv file:

! output table, date of today:
<rcbase>.output.file            :  ${my.work}/PAL_S5P_NO2_%Y-%m-%d.csv

Example records:

orbit;         start_time;           end_time;processing;collection;processor_version;filename                                                                              ;href
02832;2018-05-01 00:00:52;2018-05-01 01:42:22;PAL_      ;01        ;020301           ;S5P_PAL__L2__NO2____20180501T000052_20180501T014222_02832_01_020301_20211108T132200.nc;https://data-portal.s5p-pal.com/cat/sentinel-5p/download/c3e90b62-c1f6-47b6-9ed7-bd70aa6f46ce
02833;2018-05-01 01:42:22;2018-05-01 03:23:52;PAL_      ;01        ;020301           ;S5P_PAL__L2__NO2____20180501T014222_20180501T032352_02833_01_020301_20211108T163508.nc;https://data-portal.s5p-pal.com/cat/sentinel-5p/download/a08cda20-0018-434e-bdcc-800dd580db0f
:
class cso_pal.CSO_PAL_Downloader

Bases: object

Class to download single file from the Product Algorithm Laboratory.

The DownloadFile method should be used to actually download a file.

Usage:

# initialize downloader:
downloader = CSO_PAL_Downloader()
# download file, store in specified file:
downloader.DownloadFile( "https://data-portal.s5p-pal.com/cat/sentinel-5p/download/88c15681-db43-4219-b391-c8567e39cccf", "orbit.nc" )
DownloadFile(href, output_file, maxtry=10, nsec_wait=5, nsec_wait_max=600, dmode=None, indent='')

Download file from PAL.

If a request fails it is tried again up to a maximum of maxtry times, with an initial delay of nsec_wait between requsts.

Arguments:

  • href : download url, for example:

    https://data-portal.s5p-pal.com/cat/sentinel-5p/download/88c15681-db43-4219-b391-c8567e39cccf
    
  • output_file : target file

Optional arguments:

  • maxtry : number of times to try again if download fails

  • nsec_wait : initial delay in seconds between requests; with every new attempt, this will be increased up to a maximum of nsec_wait_max

  • dmode: directory creation mode, e.g. 777