ngEO Architecture

BROW Architecture

Entirely based on Open Source Software:

• GDAL for raster processing
• MapServer for OGC services support
• EOxServer for Earth Observation extension
• MapCache for extremely well performing WMTS and WMS access

OGC's WMTS and WMS Standards

Configuration from ngEO Controller

Data ingested by ngEO FEED

Authentication using Shibboleth

Authorization from ngEO Web Server

Flow of Browse Images

Ingestion of Browse Images

Preprocessing

• Input Geographic Metadata for Geo-referencing
  • Footprint polygon - footprint
  • Regular grid of tiepoints - regularGrid
  • Pre-georeferenced images
    • rectifiedBrowse
    • modelInGeotiff
• Optimizations
  • Footprint generation
  • Re-projection
  • Addition of alpha-channel
  • Internal tilling
  • Overviews
  • Compression

TBD

Retrieval of Browse Images

BROW Components

BROW Component Core

BROW Core Data Model

Technology Baseline

• CentOS 6 64bit repositories (base, extras, updates) based on RHEL 6
  • Apache HTTP server 2.2: httpd, mod_wsgi
  • PostgreSQL 8.4: postgresql-server, postgresql
  • Python 2.6: python, python-lxml, python-psycopg2, pytz
• EPEL & ELGIS repositories
  • Django 1.4: Django14
  • PROJ.4 4.8: proj
  • GDAL 1.9: gdal, gdal-python
  • PostGIS 1.5: postgis
• EOX repository
  • libxml2 2.7: libxml2, libxml2-python - GML patch
  • MapServer 6.2: mapserver, mapserver-python - 6.0 otherwise
  • MapCache 1.2; 1.3dev: mapcache
  • EOxServer 0.3.1; 0.3dev: EOxServer
  • ngeo.b.core 1.0.2; 2.0dev: ngEO_Browse_Server

Development & Testing

• Git hosted on GitHub
• Vagrant & VirtualBox (see HOWTO)
• Jenkins CI
• Python/Django unit test framework
• Performance tests using JMeter
• Integration testing on OpenStack platform provided by Task 5

BROW Deployment Basic

BROW Deployment Multiple

BROW Deployment Alternative

BROW Installation

Changes

• Tile merging limit per tile instead of per browse layer (demo)
• Merge images during ingestion (S1)
• Asynchronous seeding
  • Faster synchronous part for FEED
  • Synchronization between BROW components/Consistency checks
  • Improved performance in case of merging
  • Delay in availability on WEBC

Security

• Authentication using Shibboleth
  • BROW Deployment Recommendation
    • Separate instances for Open and Protected browse layers
    • Pro: Far easier configuration of Shibboleth e.g. redirects
    • Con : Small operations overhead
• Authorization
  • Alternative 1: ngEO-CP
    • Harmonization in ngEO
    • Depending on design and implementation
  • Alternative 2: BROW Custom
    • Middleware in MapCache calling simple tool using memcached to obtain decision

Communication with CTRL

• Done
  • Register/Unregister
  • Status
  • Log
• To be done
  • Global and specific configuration
    • Additional parameters e.g. max number for tile merging, default time interval in WMTS
  • Pause/Resume/Stop/Restart
  • Notifications
  • Reporting

Status

• V1
  • Finished 6 months ago
  • Waiting for final closure
• V2
  • Finished sprint 1 and parts of 2
  • Continued once V1 is closed
• Sidestep Task 5
  • ngEO-MM Reference Platform
  • Current status
  • Datasets: Landsat TM & ERS
  • Issues reported to Jira e.g. NGEO-926, NGEO-927, NGEO-928, NGEO-940