Certainty or Flexibility of accessA Bureau of Meteorology perspectiveDr Bruce W ForganObservations and Infrastructure Division

RadComms 2014

Certainty or Flexibility of Access?

And the answer is…..

Certainty through minimizing measurement uncertainty ……and

Flexibility of access in using new communications systems for weather measurement

RadComms 2014

Measure to Manage

Measurements of the earth and atmosphere provide the information we need to manage the planet.

Informed management is essential for :

• Weather and climate forecasting

• Water availability;

• Climate change mitigation and adaptation;

• Response to natural disasters;

• Biodiversity protection;

• Monitoring the health of the ocean.

Earth measurements help us:

• Understand and predict changes in the environment;

• Manage natural resources to meet economic, social and environmental needs.

RadComms 2014

What is Derived from Measurements?

The planet’s fundamental constituents and processes, including:• Atmospheric water vapour and cloud liquid water• Precipitation including rain, ice (hail) and snow • Atmospheric temperature profiles • Soil moisture• Ocean salinity • Wind speed and direction• Land and sea surface temperature• Cloud temperature and cover• Ice cover• Vegetation biomass

• Atmospheric chemistry, e.g. carbon, nitrogen and sulphur-based gases (CO2, CO, NO, SO

2, etc.)

• Suspended particulate matter (aerosols), e.g. volcanic ash, dust

Spectrum is essential for observing the earth and delivering the outcomes

It requires close cooperation in effective spectrum protection, management and access to telecommunications 'meta data'

RadComms 2014

Microwave Measurement TechnologiesSatellite & Surface – the How

Principles of Passive and Active Sensing

Passive Sensors

… measure electromagnetic radiation at microwave frequencies emitted by constituents of the Earth and its atmosphere.

Active Sensors

… receive signals that they have transmitted, after these signals have been reflected by land/ocean surfaces, by atmospheric hydrometeors, or by variations in the refractive index of air.

RadComms 2014

Information for Users & Policy Development(Environmental Intelligence)

RadComms 2014

Information Derivedwith significant measurement uncertainty

RadComms 2014

Source of Measurement Uncertainty?

• Earth Observation community is an extensive user of bands in the spectrum

• Measurements in bands are used for deriving :− molecular constituents

− greenhouse gases

− water vapour

− temperature

• Different parts of the bandinform for different heights

• Different bands equate todifferent parameters

• Unknown sources in bands- increase uncertainty

RadComms 2014

Basic Physics – radiative transfer equation

• Unexpected or too noisy sources in a band corrupt the derived values

RadComms 2014

Impact of Increased Uncertaintyfrom sources of unknown magnitude

RadComms 2014

Example of Surface-based Active Remote Sensing

Surface-Based Active Sensing• Doppler and non-Doppler weather radars S,C and X band (2.7…10 GHz)

– rainfall amount & intensity, wind speed and direction

• Wind profiling radars (50 MHz, 1 GHz)− Provide wind speed and direction profile from near ground to the stratosphere directly above

the radar, depending on the frequency.

RadComms 2014

Increased Uncertainty for Radar

C-band weather radars

• The Bureau operates over forty C-band weather radars;

• Over $200 million investment in hardware and service delivery systems, plus $$ billions in value to the community, etc.

• Threatened by RLAN noise , particularly if airborne.

RadComms 2014

With satellite data to use – forecast rain fields

RadComms 2014

What is there satellite datawas too uncertain to use?

RadComms 2014

Economic Value

The protection of spectrum used for passive and active Earth observations requires a global perspective.

• Earth observations, whether made from space or from terrestrial networks, are shared globally between meteorological agencies free of charge, for the benefit of all countries in protecting life and property.

Australian Perspective• Earth observations sector contributes an estimated $4 billion to the GDP as of Sep 2014.• Entirely dependent on Earth observation satellites funded and launched by other countries

with a 10-15 year lead time.• In return we provide science and mission support to these countries:

− Validation and calibration of sensors, e.g. CP2 radar in Brisbane for GPM, OzNet Hydrological monitoring network (Australian Universities) .

− Satellite command and control, e.g. Bureau Turn Around Ranging Station for Chinese FENGYUN geostationary satellites.

RadComms 2014

A Spiky Beanstalk on my Roof providing Cake!

RadComms 2014

Certainty in Measuring to Manage

Measurements - space and surface platforms

• Active and passive sensing in multiple noise/contamination free bands

Communicating

• Integral to measurement transfer process

• Essential for transmission of measurements and derived data

Informing

• Service delivery

• Point to point

• Broadcasting

Spectrum is a shared resource to achieve mutually beneficial outcomes

Bruce W Forgan03 9669 4111b.forgan@bom.gov.au

Thank you…

'The one thing you can't trade for your heart's desire is your heart.'Louis McMaster Bujold, Memory