DBCP DRIFTER Iridium Pilot Project

At its twenty-sixth session, La Jolla, USA, 16-20 October 2006, the Data Buoy Cooperation Panel (DBCP) agreed to actively pursue technology evaluation initiatives. A proposal to establish an Iridium Pilot Project was presented to the session, and the Panel agreed that it was now in a position to put into action the various additional activities that it had approved in principle during the session, particularly the Iridium Pilot Project.

This document, approved by the DBCP Executive Board, will establish the “DBCP drifter Iridium Pilot Project”, which will run for a period of two years as of November 2006, the project’s Terms Of Reference and its Steering Team. The pilot project is particularly timely in view of developments in GEOSS and disaster monitoring, in recognition of the ways in which the WMO proposes to handle its future information requirements (e.g. WMO Information System), and that many Panel members are already active with Iridium. In addition, the use of GPS for location purposes will provide for precise timing of observations for future observational requirements.

DBCP drifter Iridium Pilot Project, Nov. 2006, p. 1

1) Aims of the Pilot Project

In the first instance, the goal of the Pilot Project will be to evaluate and demonstrate the operational use of Iridium satellite data telecommunication technology for the real-time collection of drifter data in support of the WWW, GOOS, and GCOS applications, and the WMO Natural Disaster Prevention and Mitigation Programme. In addition, the Pilot Project will aim to evaluate whether this can be realized in a cost effective way, on a global basis, and under various ocean conditions. Deployment of drifters in data sparse areas of interest to developing countries will also be targeted.

The Pilot Project will seek to evaluate the feasibility of Iridium technology for real-time telecommunication of drifter data, relating to:

1)Operating a global observing system (at least 50 units deployed worldwide);

2)Network reliability and survivability;

3)Data throughput in terms of quantity and timeliness;

4)Data management, especially data formatting and insertion on the GTS;

5)Operational shipment and deployment, including rapid response options (e.g. ahead of tropical cyclones);

6)Cooperation with developing countries in terms of drifter deployment and Iridium technology transfer;

7)Collaboration with manufacturers to promote free availability of Iridium modems and drifters

8)Demonstrating overall cost effectiveness (manufacturing, transmission, data processing, life-time);

2) Evaluation of the global system

A sufficient number of drifters will have to be deployed in order to provide reliable evaluation of performance and to assess whether an Iridium drifter network can work in any ocean area and under various ocean conditions. When referring to a global observing system it is understood that drifters used for this project will be deployed in all ocean basins, including both the Northern and Southern Hemispheres, in tropical regions, in mid-to-high latitudes, and in the Polar regions. The goal is to show that the instruments will work in harsh sea environments, high winds, and under a wide range of temperatures. To that end, it is proposed to build and deploy at least 50 units.

3) Support to Natural Disaster Prevention and Mitigation applications

Of particular interest will be hurricane and storm surges monitoring and forecast activities. All drifters will measure SST and most will be drogued at 15 metres. Some of the units will be deployed as hurricane drifters and report one or more of the following variables: sea level pressure, wind speed, wind direction, waves, sub-surface temperature profiles using thermistor strings. Development of rapid deployment technology will be part of the Pilot Project’s activities (deployment package, certification for air deployment, small hull, two-way communications for targeted/adaptive sampling (e.g. storm buoy mode).

4) Capacity Building

Developing countries will be invited to participate in the Pilot Project by providing for deployment opportunities in their regions of interest. The Pilot Project may wish to highlight deployments of drifters in the Western Indian Ocean and/or the Gulf of Guinea as these have been identified as data sparse areas. The Pilot Project will seek transfer of technology through the participation of experts from developing countries in the project and through publication of documentation.

5) Hardware

Buoy operators and manufacturers will be invited to participate in the Pilot Project so as to:

  • Identify appropriate transmitters and GPS units (e.g. Iridium 9601 device).
  • Mount these on drifters and developing appropriate on-board software.
  • Provide cost effective manufacturing. A sufficiently large number of drifters will be equipped with such transmitters and GPS receivers and the resulting drifter design should permit routine production of operational units at reasonable cost.
  • Ensure that the electric power consumption is acceptable so that drifter life-times exceeding one year are achieved. The overall cost effectiveness of Iridium drifters will have to be assessed through the computation of metrics involving hardware, packaging, shipping, satellite data transmission, and data processing costs.
  • Collaborate in the design of reliable deployment packages for deployment by ship and/or air, and reliability of drifter shipping to remote regions and developing countries.

6) Data Management

The Pilot Project will assess the feasibility of converting collected data to geo-physical units, applying appropriate automatic quality control procedures, encoding the data according to WMO GTS standards, and distributing the data in real-time onto the GTS. Membership of the pilot project will include data management centres or agencies which are willing and able to provide such support.

Pilot Project membership will also include the DBCP Evaluation Group, who will assist in the definition of a standard Iridium data transmission message format, and in the evaluation of results (e.g. see format being used by Météo France in annex D).

7) Iridium and its VAR network, Interested buoy operators, DBCP members, and other interested partners

This group will be invited to offer one or more of the following:

  • Provision of Iridium data telecommunication costs (air time)
  • Provision of Iridium data telecommunication units
  • Provision of drifters
  • Testing and calibrating instruments
  • Deployment of drifters in their area of interest
  • Shipping units to remote regions and developing countries
  • Provision of deployment opportunities
  • Assistance with the establishment of a data routing architecture
  • Assistance with the collection of performance statistics (eg. Transmission failure rates, bit errors, call drops, timeliness, etc.)

8) DBCP Evaluation Group

The Evaluation Group will specifically address the following issues;

  • Instrument performance evaluation
  • Evaluation of the quality of returned GPS fixes
  • Evaluation of data timeliness
  • Designing and proposing a standard Iridium data transmission message format (e.g. see annex D)
  • Proposing engineering/housekeeping parameters to be transmitted
  • Proposing best ways of measuring certain variables (e.g. temperature profiles, wave data)
  • Proposing best way of using two-way satellite data telecommunication for adaptive/targeted sampling (e.g. storm mode)

9) Project organization, time frame and reporting

A Steering Team for the Pilot Project has been established. The Steering Team is chaired by the DBCP Chair. The Terms of Reference and Membership for the Pilot Project Steering Team are given in Annex A.

The Pilot Project will start as of November 2006 for an initial two-year period and will report to the DBCP on progress at its annual sessions. The Steering Team will communicate mainly via email and will meet as the need arises. Participants at Pilot Project meetings will be expected to attend at their own expense although some limited funding might be considered by WMO to support such meetings. Secretariat support for the PP will be provided by WMO and IOC.

10) Initial Membership and participation

Participation in this Pilot Project is open to other organizations, agencies, institutes, private companies willing to commit resources to the Pilot Project. Interested parties are invited to submit a letter of intent to the DBCP Chair with copy to the WMO and IOC Secretariats. The letter of intent should include indication of the likely support/facilities that will be offered to the Pilot Project.

The list of individuals who expressed interest in the Pilot Project is given in Annex B. Participating agencies and their initial commitments are listed in Annex C. Others are free to join provided they have contributions to make to the Pilot Project.

11) Coordination and Information Exchange

The Technical Coordinator of the DBCP, Ms Hester Viola (), will provide coordination for the Pilot Project. The Coordinator will collect and compile information from the participants, including the following:

  • List of commitments by the participants
  • Deployment plans
  • List of deployed Iridium drifters, including WMO numbers, GTS bulletin headers, deployment information (date, time, location, type), lists of installed sensors, and any additional technological information and metadata that might be useful for the Pilot Project
  • Quality evaluation results (life-time, quality of transmission, timeliness, data quality)

A mailing list for the Pilot Project will be established: .

Individuals interested in being registered with the mailing list are invited to contact the Technical Coordinator of the DBCP.

A “Wikipedia” web site will be established for the Pilot Project by the Technical Coordinator of the DBCP. Exact URL for the web site will be communicated by email to the participants.

12) Workplan

An initial work-plan for the Pilot Project will be drafted by the Chair of the Steering Team.

Annex A

Terms of Reference for the Steering Team of the

DBCP Drifter Iridium Pilot Project

(DBCP Iridum-PP)

The Pilot Project will evaluate and demonstrate the operational use of Iridium Satellite data telecommunication technology for the real-time collection of drifter data in support of the WWW, GOOS, GCOS, and Natural Disaster Prevention and Mitigation applications.

The Pilot Project will run for an initial two-year period as of November 2006 and will report to the DBCP on progress at its annual sessions.

The Pilot Project will seek to evaluate the feasibility of Iridium technology for drifters in terms of:

9)Operating a global observing system (at least 50 units deployed worldwide);

10)Network reliability and survivability;

11)Data throughput in terms of quantity and timeliness;

12)Data management, especially data formatting and insertion on the GTS;

13)Operational shipment and deployment, including rapid response options;

14)Cooperation with developing countries in terms of drifter deployment and Iridium technology transfer;

15)Collaboration with manufacturers to promote free availability of Iridium modems and drifters

16)Overall cost effectiveness (manufacturing, transmission, data processing, life-time);

The Steering Team is tasked to guide the Pilot Project in achieving the tasks described above.

Steering Team Membership

The Steering Team is comprised of the following individuals:

  • David Meldrum, SAMS, UK, Chair, Iridium PP Steering Team ()
  • Hester Viola, Technical Coordinator, DBCP, France ()
  • Jon Turton, MetOffice, UK ()
  • Yvonne Cook, MSC, Environment Canada ()
  • Bill Burnett, NOAA/NDBC, USA ()
  • Steve Piotrowicz, Ocean US ()
  • Sergey Mothyzev, Marlin Yug, Ukraine ()
  • Bill Woodward, CLS America, USA (bwoodward @clsamerica.com)
  • Ngoc Hoang, NAL Research Corporation, USA ()
  • M. Ravichandran, INCOIS, India ()

Secretariat support is being provided by WMO and IOC. Contact points:

  • Etienne Charpentier, WMO, Switzerland ()
  • Boram Lee, IOC, France ()

Annex B

DBCP Drifter Iridium Pilot Project initial membership

The Pilot Project includes, to the greatest extent feasible, participants from the affected and interested marine community groups. The following individuals have expressed interest in participating in the Pilot Project:

Chairperson, Iridium PP

  • David Meldrum, SAMS, UK, Chair, DBCP ()

Coordination and information exchange

  • Hester Viola, Technical Coordinator of the DBCP, JCOMMOPS, France ()

Buoy operators, instrument evaluation, contributors

  • Elizabeth Horton, Navoceano, USA, Vice-Chair, DBCP ()
  • Steve Piotrowicz, Ocean US, USA ()
  • Jon Turton, Met Office, UK ()
  • Yvonne Cook, MSC, Environment Canada, Canada ()
  • Graeme Ball, BOM, Australia ()
  • Ali Mafimbo, KMD, Kenya (, )
  • Jean Rolland, E-SURFMAR, France ()
  • Julie Fletcher, MSNZ, New Zealand ()
  • Julie Thomas, SIO, USA ()
  • K. Premkumar, NIOT, India ()
  • M. Ravichandran, INCOIS, India ()

Iridium

  • Scott Scheimreif, Iridium Satellite LLC, USA ()
  • Bill Woodward, CLS America, USA (bwoodward @clsamerica.com)

Data Management, GTS

  • Bill Burnett, NOAA/NDBC, USA, Chair, DBCP Evaluation Group ()
  • Christian Ortega, CLS, France ()

Manufacturers

  • Jeff Wingenroth, Technocean, USA ()
  • Sergey Mothyzev, Marlin Yug, Ukraine ()
  • Andy Sybrandy, Pacific Gyre, USA ()
  • Tony Chedrawy, Metocean, Canada ()
  • Ngoc Hoang, NAL Research Corporation ()
  • Reo Phillips, Axys, Canada ()
  • Helen Cussen, Trident Sensors, UK ()

Secretariats

  • Etienne Charpentier, WMO, Switzerland ()
  • Boram Lee, IOC, France ()

Annex C

Iridium Pilot Project participating agencies and initial commitments

Agency / Commitment / Drifters 2007 / Drifters 2008
DBCP / Additional cost to put Iridium on drifters (call for proposals for 10 drifters) / 10
SAMS / 10 Drifters (depl. Location to be decided), 1 inAntarctica / 11
Ocean.US / Funding for Iridium modems, Iridium upgrades, and/or Iridium air time
NOAA/AOML / Drifters
Meteo-France / 5 Drifters, transmission format (e.g. annex D), GTS data distribution for the committed drifters / 5
UK Met Office / Drifters (Southern Ocean) / 2
US Coast Guards / Drifters (Davis type)
Environment Canada / Barometer upgrades with Iridium, tests on ships (AVOS) and moorings
Commander, Naval Meteorology and Oceanography Command / Drifters, Air Deployments, liaison with US Coast Guards / 2
Kenyan Meteorological Department / Deployments (Western Indian Ocean)
Australian BOM / Deployments (Indian Ocean, Southern Ocean)
MSNZ, New Zealand / Deployments (Tasman Sea)
SAWS, South Africa / Deployments (South Atlantic, Indian Ocean, Southern Ocean)
INCOIS / 3 drifters (Indian Ocean), deployments (Indian Ocean), assistance with the collection of performance statistics. / 3
Iridium Satellite LLC / To be defined
CLS / Data Management/QC/GTS
CLS America / Iridium Value Added Reseller, Iridium data telecommunication
NOAA/NDBC / Data Management/QC/GTS
NAL Research Corporation / To be defined
Trident Sensors / To be defined
Technocean / Technological developments, quality evaluation, additional cost to put Iridium on drifters
Marlin Yug / Technological developments, model integration, deployments, transmission formats
Pacific Gyre / 3 SVP drifters (excluding air time, barometer) / 3
Metocean / Iridium air time, Drifter Engineering and Development, investigations regarding Data Management/QC/GTS
Axys / Technical evaluation and reporting, web display, GTS distrib. testing, integration in buoys and AVOS
WMO / Secretariat’s support
IOC / Secretariat’s support
TOTAL / 36 / 20
Annex D

Iridium transmission format

Of Météo France SVP-B prototype drifters

Two prototypes were ordered to Metocean in 2006. They were delivered by the end of September. Tested ashore – and in the Bay of Brest during a few hours – they show a nominal functioning. One of them was deployed off France the 26 October 2006 and started reporting on GTS under WMO number 62508, and SSVX13 LFPW GTS bulletin header. The second is planned for deployment East of Newfoundland in mid-November 2006.

1. Format(version 2 – used on these first two prototypes)

Parameter

/ Bits / Pos / Min / Max / Formula
Mode / 2 / 0 / 0 / 3 / Fixed = 3 (011)
Time (since Jan. 1st 00:00 ) / 16 / 2 / 0 / 16383 / Hour (UTC) = n * 0.25
Latitude / 20 / 18 / -90 / 98 / Lat (deg) = n*0.00018 - 90
Longitude / 21 / 38 / -180 / 197 / Lon (deg) = n*0.00018 - 180
Air pressure / 11 / 49 / 850 / 1054.7 / AP (hPa) = n*0.1 + 850
SST / 9 / 60 / -5 / 35.88 / SST (°C) = n*0.08 - 5
Pressure tendancy / 9 / 69 / -25.5 / 25.6 / dP (hPa) = n*0.1 - 25.5
Submergence count / 6 / 78 / 0 / 100 / Subm. (%) = n * 1.5873
Battery voltage / 3 / 84 / 10.75 / 16.75 / Vbat (V) = n*0.75 + 10.75
Time to first GPS fix / 7 / 87 / 0 / 254 / TTFF (s) = n * 2
Iridium transmission duration / 8 / 94 / 0 / 255 / SBDT (s) = n
Data Checksum / 8 / 102 / 0 / 255 / 8 lowest bits of the sum of the first 14 bytes

Columns :

-Mode is used to describe the type of data (Meteo-France convention - “3” is used for drifting buoys).

-Column “Bits” : length of the word in bits for the parameter;

-Column “Pos” : Start bit in the message for the parameter;

-For some parameters, “Max” is just an approximation;

-Total length of the message : 15 bytes.

Remarks for version 3 :

  1. We need a second “Time” parameter for the position. As for the observation time it will be the number of quarter of an hour elapsed since the 1st January of the current year. Two more bytes will be needed.
  2. As far as the Iridium transmitter has it owns checksum, it seems not necessary to keep an additional one in the message.

2. Operating principle for the first two prototypes:

-One observation every hour. One GPS position 8 times a day: 00, 03, 06, 09…

-Iridium transmission at HH+11 minutes;

-Raw data are received through email within one minute (two addresses : one for operational use, one for test purposes);

-GTS data transmission from CMM during the software evaluation (first few weeks after deployment); from Météo-France operational transmission service later. The software is almost ready;

-WMO ids will be 62508 and 62509.

3. Studies:

Each Iridium transmission is fitted with a location and an error estimation (CEPRadius). Comparisons between Iridium and GPS positions have been carried out when the buoys were ashore. They have been promising, at least for meteorological purposes.

An evaluation of Iridium locations will be conducted to see if the buoys could work without GPS. The principle would consist in keeping the most recent reliable positions into the data processing ashore in order to be able to filter wrong ones.

The GPS is energy consuming. The two prototypes get only 8 GPS positions a day to save energy. This sampling will spend more energy than for Argos drifters.

The advantage/drawbacks of 24 regularly sampled but inaccurate Iridium positions compared to the present 8-10 Argos positions provided by standard SVP-B drifters and 4 accurate GPS positions will be assessed.

Without GPS :

-the lifetime of the drifters will be significantly higher (no device to power and shorter Iridium SBD message : 8 bytes instead of 16);

-their cost will be lower.

Pierre Blouch, Météo France