Report of the
EUFAR FP7
N6SP, IWGADTS and
ISPRS TOR 2, 3, 11 meeting
October 25th, 2010 – Toulouse, France
Last update on 09/12/2010 by Matt FREER
1. Table of contents
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1. Table of contents 2
2. List of attendees 3
3. Meeting Summary 4
3.1. Introduction 4
3.2. ISPRS WGI/1 TOR Restructuring 4
3.3. Aircraft Payload Networks discussion 4
3.4. Data Links discussion 5
3.5. Processing Tools discussion 7
4. Conclusion 9
5. Action list 10
6. Annex I 11
6.1. Description of participating groups 11
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2. List of attendees
· Attendees:
Janine AQUINO (NCAR EOL-RAF)
Sylwester ARABAS (University of Warsaw)
Martin BACHMANN (DLR)
Bob CURRY (NASA)
Rose DOMINGUEZ (NASA)
Matt FREER (MétéoFrance)
Lawrence FREUDINGER (NASA)
Wendy GARLAND (BADC)
Stefanie HOLZWARTH (DLR)
Jason TOMLINSON (PNNL)
Chris WEBSTER (NCAR EOL-RAF)
Steve WEGENER (NASA)
3. Meeting Summary
3.1. Introduction
The joint meeting between EUFAR N6SP, IWGADTS (Inter-agency Working Group on Airborne Data and Telemetry Systems), and ISPRS (International Society for Photogrammetry and Remote-sensing) WGI/1 TOR 2,3,11 brought together members from the US and Europe with the aim of developing standards and protocols for airborne data, data-processing, data-links and networks.
The meeting began with a welcome by Matt Freer, followed by short overviews of the three groups participating in the meeting: EUFAR N6SP, IWGADTS and ISPRS WGI/1 TORs 2, 3 and 11. Descriptions of these three groups can be found in Annex I. The goal of the meeting was to discuss the combination of ISPRS TORs 2, 3 and 11 and to develop a plan for the coming year in areas where the participating groups overlap.
3.2. ISPRS WGI/1 TOR Restructuring
Following the June 2010 ISPRS WGI/1 conference in Calgary, the decision was made to combine TORs 2, 3 and 11 to reduce overlap between the groups and enable closer collaboration. To finalize the merger, a discussion was held in Toulouse to outline the new structure and goals of the combined group. The combined group's structure will loosely follow that of the three original TORs. Below is the new group structure, with associated leads:
Overall TOR2311 – Matt Freer
Aircraft Payload Networks subgroup – Jeff Myers
Data-links subgroup – Larry Freudinger
Processing tools subgroup – Chris Webster
3.3. Aircraft Payload Networks discussion
Current state
The Inter-agency Working Group for Airborne Data and Telemetry Systems (IWGADTS) has developed several recommendations for configuring aircraft payload networks. Parts of these recommendations have been implemented by many operators, both in the US and in Europe. These recommendations are:
-timing IRIG-B
-1 second feed (CSV/IWG1)
-CSV packet
NASA reported on their Global Hawk and UAV fleet network systems. On these aircraft, the minimum payload requirements are that instruments broadcast status, and ideally can be controlled remotely. Additionally, all instruments must be Ethernet capable.
DLR reported that instrument certification requirements can create a big hurdle for aircraft installation – perhaps there may be room for some kind of certification standards.
Regarding NASA instrumentation, they are using IWG1, however, its rate is too slow for most hyperspectral applications.
Vision
The vision for for aircraft payload networks is to specify and disseminate existing and new standards, in addition to recommending best practices. We aim to standardize the following areas:
· Timing (IRIG-B if possible)
· Intra-aircraft low-rate navigation feed
· Sharing of instrument status, control and data
· ARINC over Ethernet
· Ethernet interface on instruments
· Network IP layout
And disseminate the following best practices:
· Omnistar or differential GPS capability
· Attitude information co-incident with instrument (remote- sensing)
· Documentation of instrument/platform sources of error
· DHCP availability on network
Action Items
1. Advertise current best practices and disseminate IWGADTS proposals
Responsible: All
Deadline: April 2011
2. Inventory status of payload network architectures
Responsible: L. Freudinger
Deadline: April 2011
3. Research applicable standards for documenting uncertainties
Responsible: M. Bachmann
Deadline: November 2011
3.4. Data Links discussion
Current state
Current data-link systems generally involve satellite links over commercial systems including Iridium and Inmarsat, and in some cases, Ku-band. Line-of-sight communications are a possibility for high-bandwidth transmissions, but lack the wide-area coverage provided by satellites.
DLR currently has data-links available on many of their aircraft, including Inmarsat on HALO, line-of-sight microwave links on their DO228 and Cessna. They are currently adapting an optical downlink to aircraft applications.
NASA reported that they are using text messaging features on Iridium handsets to transmit platform position information. Messaging from a handset has the advantages of being small, lightweight and inexpensive. Larry Freudinger commented on the possibility of creating aircraft-tethered networks using WiMax modems. This would allow 20-30 Mbit data transfer rates between aircraft, thereby increasing situational awareness in a fleet.
Vision
The long term vision for this group is the availability of persistent intra-platform and platform-to-ground data links on all platforms. However, this was decided to be outside the scope of the current TOR. Thus, the goal for the next few years in airborne data links is to facilitate implementation of network connectivity on all platforms by making recommendations on the installation, architecture, use and planning of such connectivity. At the minimum, systems providing platform situational awareness are desired, with instrument status and control, and data transfer capabilities being provided in systems of higher complexity.
Action Items
4. Survey current use of data-links
Responsible: L. Freudinger
Deadline: April 2011
Compile survey of current usages of data-links including bandwidth requirements, problems/weaknesses with current scenarios and cost/reliability issues.
5. Develop and disseminate recommendations for implementation of a network system
Responsible: All
Deadline: November 2011
Based on current usage and envisaged future requirements, we will develop recommendations for network systems covering: installation, architecture, encryption/security, use, coverage and strategic planning.
6. Explore possibility of collaboration with operator(s) in network system implementation
Responsible: All
Deadline: November 2011
FAAM is in the process of developing a new network and data system for the BAe146 – this might provide an opportunity for collaboration on this activity.
3.5. Processing Tools discussion
Current State
There are several existing metadata standards which have been developed for airborne data including the European INSPIRE directive, NetCDF based conventions such as Climate and Forecast (CF), IWGADTS, and NCAR EOL-RAF. It was felt that there might be potential overlap between many of these current standards, so an attempt will be made to reconcile between these overlapping areas.
EUFAR N6SP is currently developing a common software toolbox called EGADS (EUFAR General Airborne Data-processing Software). EGADS is a Python-based framework and library of data-processing algorithms which allows users to easily read, process, and save data and metadata.
Vision
The first goal for processing tools is to develop and recommend a common metadata convention that is minimal and extend-able to ensure broad adoption. Following these lines, it was felt that building upon an existing convention would further help adoption. However, an issue that needs further discussion is how to properly deal with time variables. As an example, time averaging needs to be well defined – i.e. whether the timestamp on an averaged time variable corresponds to the beginning, midpoint or end of sampling period.
It was decided that supporting both binary (NetCDF and HDF) and ASCII (NASA Ames/ICARTT) formats would be useful. NetCDF is primarily used in the in-situ community, while HDF is preferred for remote-sensing and hyperspectral applications. However, with the release of HDF5/NetCDF4, the two formats are relatively interchangeable. Before settling on a final ASCII format, a study will be done to compare characteristics between the similar NASA Ames and ICARTT formats.
The metadata conventions developed by this group will include data discovery attributes to aid users and software in choosing the correct fields. Ideally, the data discovery recommendations will draw upon existing conventions. One possibility would be to use IWG1 packet parameters as the minimum set of parameters to include in data discovery. Another would be to draw keywords from the CF conventions Standard Names Table.
In addition to the development of common metadata conventions, a common data processing toolbox will be developed. The EGADS framework under development by EUFAR N6SP will be used as the base for the processing toolbox, and 'best-practice' data processing algorithms will be solicited from experts in the US and European science communities.
Action Items
7. Compare metadata conventions keywords
Responsible: M. Freer
Deadline: April 2011
Compare keywords from several metadata conventions (INSPIRE, CF, RAF, IWGADTS, etc) to find the amount of overlap, if any. Based on results, possibly develop a metadata translation library.
8. Compare and decide on ASCII format
Responsible: C. Webster
Deadline: April 2011
Compare between NASA Ames, ICARTT or RAF Ames formats to finalize group recommendation for ASCII format.
9. Contact EUFAR EWGs and US community for best practice algorithms
Responsible: M. Freer
Deadline: June 2011
10. Continue development of toolbox (EGADS)
Responsible: M. Freer
Deadline: November 2011
4. Conclusion
The combined meeting provided an excellent opportunity to develop a road-map to develop standards and recommendations for aircraft network and data system standards, taking into account ideas from both the European and US science communities. To continue discussions started at this meeting and to coordinate further work, we have implemented a mailing list at http://groups.google.com/group/isprswgi1tor2311 and a Wiki page at http://sites.google.com/site/isprswgi1torwiki.
A teleconference will be held in late January/early February to discuss progress towards the goals defined during this meeting. Results of this meeting and subsequent work will be shared at the April 2010 ISRSE meeting in Sydney, Australia.
5. Action list
1. Advertise current best practices and disseminate IWGADTS proposals 5
Responsible: All
Deadline: April 2011
2. Inventory status of payload network architectures 5
Responsible: L. Freudinger
Deadline: April 2011
3. Research applicable standards for documenting uncertainties 5
Responsible: M. Bachmann
Deadline: November 2011
4. Survey current use of data-links 6
Responsible: L. Freudinger
Deadline: April 2011
5. Develop and disseminate recommendations for implementation of a network system 6
Responsible: All
Deadline: November 2011
6. Explore possibility of collaboration with operator(s) in network system implementation 6
Responsible: All
Deadline: November 2011
7. Compare metadata conventions keywords 7
Responsible: M. Freer
Deadline: April 2011
8. Compare and decide on ASCII format 8
Responsible: C. Webster
Deadline: April 2011
9. Contact EUFAR EWGs and US community for best practice algorithms 8
Responsible: M. Freer
Deadline: June 2011
10. Continue development of toolbox (EGADS) 8
Responsible: M. Freer
Deadline: November 2011
6. Annex I
6.1. Description of participating groups
IWGADTS – Interagency Working Group for Airborne Data and Telemetry Systems
The Interagency Working Group for Airborne Data and Telecommunications Systems (IWGADTS) is a US based group organized for the purpose of developing recommendations leading to increased interoperability amongst airborne platforms and instrument payloads.
EUFAR N6SP – European Facility for Airborne Research Standards and Protocols
The main goals of EUFAR’s Networking Activity Standards and Protocols (N6SP) are to:
· ensure harmonization, integration and interoperability
· assist new/inexperienced users
· facilitate inter-calibration experiments
· allow comparison of results
· enable easier exchange of data
ISPRS WGI/1 – International Society for Photogrammetry and Remote Sensing
The primary mission of the new Working Group I/1 is to promote the standardization of instrument interfaces, data formats, and aircraft accommodations, and to facilitate more efficient, flexible, and cost-effective international science flight operations. The increased portability of instrumentation between aircraft increases the opportunities for cooperative research and can reduce the operating costs by leveraging flight opportunities. WGI/1 also will work to establish common regulatory requirements for the operation of active emitters (RF, lidars, dropsondes) and to effectively introduce UAS operations in international science campaigns.
TOR2 – Airborne sensor interface standards
TOR3 – Airborne satellite relay systems and standards
TOR11 – Data processing and format standards