User Tools

Site Tools


data:data_analysis_manual:read_catalog_python

How to read the UiO FITS files catalog in Python

read_uio_cat.py
from pathlib import Path
import pandas as pd
 
# SPICE data tree path, to be changed to your SPICE data mirror
data_path = "/archive/SOLAR-ORBITER/SPICE"      # example for IAS computing servers
 
 
def date_parser(string):
    try:
        return pd.Timestamp(string)
    except ValueError:
         return pd.NaT
 
 
def read_uio_cat():
    """
    Read UiO text table SPICE FITS files catalog
    http://astro-sdc-db.uio.no/vol/spice/fits/spice_catalog.txt
 
    Return
    ------
    pandas.DataFrame
        Table
 
    Example queries that can be done on the result:
 
    * `df[(df.LEVEL == "L2") & (df["DATE-BEG"] >= "2020-11-17") & (df["DATE-BEG"] < "2020-11-18") & (df.XPOSURE > 60.)]`
    * `df[(df.LEVEL == "L2") & (df.STUDYDES == "Standard dark for cruise phase")]`
    """
    cat_file = Path(data_path) / "fits" / "spice_catalog.txt"
    if not cat_file.exists():
        print(f'Error: Catalog file not available at {cat_file.as_posix()}')
        sys.exit(1)
    columns = list(pd.read_csv(cat_file, nrows=0).keys())
    date_columns = ['DATE-BEG','DATE', 'TIMAQUTC']
    df = pd.read_table(cat_file, skiprows=1, names=columns,
                    parse_dates=date_columns, date_parser=date_parser,
                    low_memory=False)
    # remove additional spaces from strings
    for column in ["LEVEL", "STUDYTYP", "PURPOSE"]:
        df[column] = df[column].apply(lambda string: string.strip())
    return df

Then we can read the catalog and filter it:

filter_cat.py
cat = read_uio_cat()
filtered_cat = cat[(cat['DATE-BEG'] > '2021-11-05') & (cat.LEVEL == 'L2')]

cat then contains the full catalogue (as a pandas dataframe) and filtered_cat contains a catalogue in which rows have been filtered (in this particular case) by observation date and file level.

The catalogue or filtered catalogue can be exported, e.g. to a CSV table by cat.to_csv().

data/data_analysis_manual/read_catalog_python.txt · Last modified: 2022/06/22 13:49 by eric buchlin