May 2004 Iridium Users Workshop, Seattle

National Data Buoy Center’sExperiences with Real-Time Data

Retrieval from Remote Stations using Iridium; and

Data Distribution: GTS and IOOS

Presented by:

Steve Collins

May 2004

GOES Alternative Development

• May ’02, Tasking for non-GOES communications system

• Iridium selected for best coverage

• September ’03, 2 week test on 3 meter discus buoy in Gulf of Mexico– 98% throughput, compared to 81% for GOES

• December ’03, certified for operational use– ARES payloads only

Concept of Operations (CONOPS)

• One “passive” remote modem per station (buoy or C-MAN)

• One to several “active” base station modems

• PC software-controlled base stations (W2K, Visual C++)– Automated data retrieval calls managed by ‘Station Caller’

software– Manual diagnostics/data retrieval calls managed by ‘Station

Keeper’ software

• Base stations interface remote stations to NDBC real-time system

CONOPS (continued)

• All calls originated by NDBC base stations

• Remote stations ‘listen’ for incoming calls on programmed schedule for power management

• Remote station modems controlled by ARES payload– Call answering service– Interface to payload data archive– Interface to payload test/diagnostics– Interface to payload configuration (enable/disable sensors;

manage payload timing)

Remote Station Operation

NDBC NETWORKNWCS BASE STATION

POLARIS SYSTEM(NON-NDBC OBSERVATIONS)

NEMISORACLE

DATABASE

USERS'SERVICE

PROVIDERS

USER

IRIDIUM

USER

USERS

USERS

X.25

ORION

IRIDIUM

REMOTE STATION IMPLEMENTATION

REMOTE STATION

• Initializes IRIDIUM Modem• Listens for a Base Station Call

STATION 1

STATION n

Base Station Operation

NDBC NETWORK

NWCS BASE STATION

POLARIS SYSTEM(NON-NDBC OBSERVATIONS)

NEMISORACLE

DATABASE

USER

IRIDIUM

X.25

TAURUS ORION

IRIDIUM

BASE STATION

BASE STATION – STATION CALLER• Autodials stations and retrieves data• Reformats message for real-time system

compatibility (adds simulated DAMS infoand DAPS time)

• Stores reformatted message locally• Transmits compatible message to server for non-

NDBC data via FTP (NDBC1)

BASE STATION – STATION KEEPER• Operator-driven program• Station reconfiguration and timing• Separate modem to avoid conflicts• Security feature - Ignore incoming calls

STATION 1

Real-time System Interface

NDBC NETWORK

NWCS BASE STATION

POLARIS SYSTEM(NON-NDBC OBSERVATIONS)

NEMISORACLE

DATABASE

USERS'SERVICE

PROVIDERS

USER

NASA/NDBCFIREWALLS

IRIDIUM

USER

USERS

USERS

X.25

TAURUS ORION

IRIDIUM

NDBCWEB PAGE

REAL-TIME SYSTEM IMPLEMENTATION

REAL-TIMESYSTEM

• POLARIS retrieves data from NDBC1

sent by Base Station PC

• Interfaces with TAURUS & ORION

• Interfaces with NDBC database

• Interfaces with NDBC web pages

• Internet access via NDBC web site

• NDBC intranet access through NEMIS

IRIDIUM

Base Station Issues

• Antenna cable length limited to less than 3 dB loss

• Satellite visibility

• Will require additional base stations or equipment for entire network (only 3 stations per channel with current design for 15 minute reports)

• Software allows default PIN only

• Clock must be in synch with remote stations (GPS)

Remote Station Issues

• Security

– No security “firewall” on remote stations

– Security limited to general public not knowing station phone number for incoming calls.

– Cannot make outgoing calls

Data Issues• A number of time of observation issues had to be

overcome for 15 minute observations

• Corruption of some temperature data during GOES transmission overlap time (similar to what occurs now when directional waves data acquisition overlaps GOES transmission)

• Web modifications to display multiple observations per hour, need public comment period to make public

• Will require tight configuration control and communications to avoid duplicate reports

Anticipated Improvement

Multi-channel IRIDIUM modems for base station

– reduce equipment costs

– fewer PCs and modems

– will require modifications to Station Caller and Station Keeper software

Benefits - IRIDIUM vs GOES

• Increase in data availability over GOES (so far)• Lower power requirement

– Power available for more frequent observations– Potential reduction in power systems failures

• Potential for more data– Time slots limited by NDBC controlled constraints– Message length not a factor– Retrieve missed reports

• Remote two-way communications– Remote reconfiguration– More data in changing environment conditions– Remote diagnostics

• Potential cost savings in field service using remote ‘repair’ and diagnostics• Shore-side event driven reporting possible

Remote Diagnostics

• Allows remote access to all payload test functions

• Remote soft reset of payload

• Remote access to system error info

• Parameter table downloads– Correct parameter errors remotely– Reconfigure payload

CONCERNS

• Telecommunications costs (compared to no usage costs for GOES)

• Unknown future pricing

• Base station requirements for comms with 150 remote stations

• Performance in severe environments and weather events

• Contingency Plan for Base Stations

PLANS

• Install on two new buoys, this summer– funded by USCG– Seaward end of Juan de Fuca Strait and north end of

Puget Sound– Top of hour GOES transmissions, bottom of hour

Iridium transmissions

• Install on DART buoys (PMEL development)• Install on prototype USCG Automated

Identification System (AIS) equipped buoy, late this year or early next year

Potential Plans

• Install on all moored buoys and most C-MAN platforms for USCG AIS comms

• Use for NDBC data comms?

Data Distribution:GTS and IOOS

Dissemination of non-GOES data

• Regional Observatory (University) data

• Iridium data

NDBC is a data assembly center in the IOOS architecture, receiving data from regional observatories, performing automated quality control, and distributing the data via the GTS and the NDBC web site.

Regional Observatories

Public

ftp*

* Via MODEM Kit - request from MarineObs@noaa.gov

NDBCDODSNDBCDODS

NDBC MODEM Kit(Meteorological and Oceanographic Data Exchange Module)

University Data SolutionUniversity Data Solution

Iridium data received at NDBC is packaged like GOES messages and ftp’d to the same system that puts University system observations on

the GTS

IOOS Data Distribution

• Later this year, NDBC will implement an OPeNDAP server.

• Iridium collected data will be displayed, as well as university data

• www.opendap.org

CONTACT

www.ndbc.noaa.gov

Steve Collins

steve.collins@noaa.gov

228-688-2822