Notebook

PyVIMS¶

This notebook provide and a set of example of how to manipulate the Cassini VIMS data using the python pyvims module.

Get some data¶

To start this example your need to download some data.

Here we will start with a cube (1487096932_1) calibrated with USGS-ISIS3 sofware and available on the vims.univ-nantes.fr data portal:

In [1]:

import os,wget

url = 'https://vims.univ-nantes.fr/data/isis'
flyby = 'T3'
image_id = '1487096932_1'
channel = 'ir'

f_cal = 'C' + image_id + '_' + channel + '.cub'
f_nav = 'N' + image_id + '_' + channel + '.cub'

if not os.path.isfile(f_cal):
    wget.download(url + '/' + flyby + '/' + f_cal) # Calibrated cube (IR)
if not os.path.isfile(f_nav):
    wget.download(url + '/' + flyby + '/' + f_nav) # Navigation cube (IR)

Loading a cube file¶

Import the VIMS class from the pyvims package

In [2]:

from pyvims import VIMS
cube = VIMS('1487096932_1')

print(repr(cube))

VIMS cube: 1487096932_1 [ISIS3]

Extract some metadata¶

The VIMS object provide a direct access to a subset of the cube metedata (extracted from the file header with the pvl module).

Here is a list of the metadata available about the capture time:

In [3]:

# Acquisition start time (as `datetime` object)
print('Start: {}'.format(cube.start))

# Acquisition stop time (as `datetime` object)
print('Stop: {}'.format(cube.stop))

# Acquisition mid-time (as `datetime` object or `%Y-%m-%dT%H:%M:%S.%f` format)
print('Mid-Time: {} / {}'.format(cube.dtime,cube.time))

# Image year
print('Year: {}'.format(cube.year))

# Image day of the year
print('DOY: {}'.format(cube.doy))

# Image decimal year
print('Decimal year: {}'.format(cube.year_d))

# Image date (as `%Y/%m/%d` format)
print('Date: {}'.format(cube.date))

Start: 2005-02-14 18:02:29.023000
Stop: 2005-02-14 18:07:32.930000
Mid-Time: 2005-02-14 18:05:00.976500 / 2005-02-14T18:05:00.976500
Year: 2005
DOY: 45
Decimal year: 2005.12054795
Date: 2005/02/14