ADEN: Ground Segment Development
VEGA and ESRIN worked together to design and developed ADEN PDS
components, and installed them at ESRIN, at an Off-Line Archive
Processing (OLAP) Centre and at ground stations in the ADEN
region.
Challenge
The Advanced Land Observing Satellite (ALOS) was conceived by
the Japanese Aerospace Exploration Agency (JAXA), and was designed
to support regional observation, disaster monitoring, cartography
and resource surveying. The mission concept called for data to be
made available through regional partners with responsibly for
servicing requests for data in their geographical areas. The ALOS
remote-sensing instruments are:
- A Panchromatic Remote-sensing Instrument for Stereo Mapping
(PRISM) for digital elevation mapping
- Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2)
for precise land coverage observation
- A Phased Array type L-band Synthetic Aperture Radar (PALSAR)
for day-and-night and all-weather land observation
ESA is the regional partner responsible for developing and
operating the necessary infrastructure in the Europe, Africa and
Middle East region. This infrastructure is referred to as the ALOS
Data European Node (ADEN).
The Payload Data Segment (PDS) is a major component of the ADEN.
In 2002, a VEGA-led consortium was selected by ESA’s Research
Institute (ESRIN) to develop the ADEN PDS. The contract called for
VEGA to design and develop ADEN PDS components, and to install and
support them at ESA’s Research Institute (ESRIN), at an Off-line
Archive Processing (OLAP) Centre and at one or more ground station
located in one of the ESA member states and/or elsewhere in the
ADEN region, including Africa.
Value delivered
The ADEN PDS provides both an Off-Line Service and a Near Real
Time Service. The main features of the Off-Line Service are:
- Data ingestion – most data is supplied on magnetic media from
Japan
- Data archiving and retrieval – designed to be compatible with
existing archives
- Data processing – science processing algorithms are hosted on a
Linux cluster
- Product dissemination – either on magnetic media or via
FTP
- User requests – mediated by ESRIN’s Technical User Services
Centre (TUSC)
- Mission planning – co-ordinated with the ALOS mission control
centre in Japan
Reflecting the increasing importance of EO data to disaster
relief efforts, rapid access to products is also possible, using
the Near Real Time Service. Raw data can quickly be acquired
directly from the ALOS satellite by an X-band station and products
derived from this data can then be disseminated within hours.
Re-use potential
The ADEN PDS was designed with re-use in mind. The system design
is modular, portable, scalable and flexible. Key features
include:
- Interfaces to existing back-end archive and retrieval
systems
- Scaleable science processing architecture able to support third
party algorithms
- Realisation of subsystems as "Generic Elements"
- Support for interfaces to ESA multi-mission facilities
- Scaleable system architecture based on PC Server and Linux
Platform