Ministac

Ministac is a minimalist Spatio-Temporal Asset Catalog. It allows for instance an institution to have a searchable catalog of their in house satellite images

Features

Manages metadata satellite images (items) and satellites images collections
Stores information in Postgres database
Search catalog using geojson geometry, temporal window, and/or cloud cover
Complies with Spatio-Temporal Asset Catalog specifications
Metadata validation against JSON schemas of stac-spec
Built to work with:
- ministac-admin (helper scripts to generate the catalog from multiple collections)
- ministac-api (JSON REST API)
- ministac-client (does not exist yet)

Installation

A complete installation requires the package, a postgres database with PostGIS extension, and a configuration file with database credentials.

Python package

Activate a python 3 virtual environment and run:

pip install ministac

Database

Install postgresql and PostGIS
Create the ministac database
Enable PostGIS extension for the ministac database

createdb ministac
psql ministac -c "CREATE EXTENSION postgis;"
psql ministac -c "CREATE EXTENSION postgis_topology;"
# Optionally create dedicated user (probably better for remote access)
psql ministac -c "CREATE USER ministac_user WITH PASSWORD 'qwerty' CREATEDB;"

Configuration file

The configuration file must be named ~/.ministac; it contains the database access credentials.

[ministac]
db_database=name_of_the_database
# Optional, depending on database configuration (running on localhost or remote, require password, etc)
# db_hostname=
# db_username=
# db_password=
# db_port=

Usage

Although ministac has a functional API, most common use cases are probably covered by ministac-admin and ministac-api. Nethertheless here are some basic examples of direct use.

import json
from pprint import pprint
import datetime as dt

import ministac
from ministac.db import init_db, session_scope


# Create database tables
init_db()

# Open example collection from test directory of the ministac repository
with open('tests/data/collection_0.json') as src:
    landsat_8_collection = json.load(src)

# Register the Landsat 8 collection to the database
with session_scope() as session:
    ministac.add_collection(session, landsat_8_collection)

# Read some example items
with open('tests/data/item_list.json') as src:
    item_list = json.load(src)

# Ingest the items to the database
with session_scope() as session:
    ministac.add_items(session, item_list, 'landsat_sr_8')


# Query the entire landsat_sr_8 collection
with session_scope() as session:
        pprint(ministac.search(session, 'landsat_sr_8'))

# Add temporal filter
startDate = dt.datetime(2017, 12, 1)
with session_scope() as session:
    pprint(ministac.search(session, 'landsat_sr_8', startDate=startDate))

# Spatial filter
geom = {'coordinates': [[[-101.7, 19.59],
                         [-101.66, 19.54],
                         [-101.61, 19.56],
                         [-101.64, 19.58],
                         [-101.57, 19.63],
                         [-101.54, 19.66],
                         [-101.6, 19.68],
                         [-101.64, 19.64],
                         [-101.7, 19.59]]],
        'type': 'Polygon'}

with session_scope() as session:
    pprint(ministac.search(session, 'landsat_sr_8', geom=geom))

# Filter with cloud cover threshold
with session_scope() as session:
    pprint(ministac.search(session, 'landsat_sr_8', maxCloudCover=20))

Ackowledgements

This project received funding from CONABIO (Mexico's national commission for biodiversity research).

loicdtx / ministac