Satellites

How we use satellite data

We use data from more than 40 geostationary and polar-orbiting satellites. 

Satellites provide more than 90% of the data used in weather forecast models. Their imagery provides vital situational awareness that enhances forecast accuracy and timeliness.

Satellite data has a wide range of applications. For example, we use it on our weather map and to:

• track severe weather location and intensity
• monitor solar radiation
• map sea surface temperatures
• inform vegetation indices used to monitor plant health
• monitor grassland curing (drying) for fire agencies
• calculate atmospheric motion vectors to estimate wind speeds
• monitor ash from volcanic eruptions
• detect Antarctic sea ice to assist ship navigation.

You'll find many products using satellite data on our current website – we're still building this new one.

Geostationary satellites

Geostationary satellites circle the Earth over the equator at a height of about 35,800 km. They follow the Earth’s rotation to complete one orbit every 24 hours.

These satellites remain over the same location above the equator. This means they can take constant and frequent images of a given region of Earth's surface and atmosphere.

There are several such satellites positioned around the globe. We use data from many of these in forecast modelling systems. Japan’s Himawari satellites are perfectly positioned to provide constant observations for Australia.

Himawari-9

Himawari-9 is the Japan Meteorological Agency's current operational satellite. Himawari means 'sunflower' in Japanese.

The satellite, launched in 2016, carries an instrument called the Advanced Himawari Imager. This instrument observes the Earth, ocean and atmosphere in 16 frequencies or 'bands', every 10 minutes. 

Data from each band is turned into images. Sometimes, images from multiple channels are combined to create a more detailed picture. For example, combining visible and infrared data can help distinguish between clouds and surface features. Himawari-9 images have:

• visible imagery at 500 m spatial resolution 
• infrared (thermal) imagery at 2 km spatial resolution.

The images enable forecasters to monitor the intensity of tropical cyclones over the ocean. This supports warnings for coastal cities and towns. They also help forecasters to identify:

• thunderstorms as they develop, and track them
• volcanic ash, fire and smoke
• fog and low cloud for use by airlines.

Rapid updates from Himawari satellites

Under a special arrangement with the Japan Meteorological Agency, the Bureau can request 'rapidscan' images. These are rapid 2.5-minute updates of areas with:

• fast moving weather events such as thunderstorms and bushfires
• volcanic eruptions.

The Bureau and the Japan Meteorological Agency have agreed to collaborate on the next satellite, Himawari-10. Under this agreement, the Bureau will have dedicated access to rapidscans for the Australian region.

Polar orbiting satellites

Polar orbiting satellites for weather forecasting move in a circular orbit. They travel from pole to pole, at a height of about 700–850 km. As the Earth rotates below, polar orbiting satellites provide global coverage.

They are closer to the Earth than geostationary satellites. This means they can provide more detailed images (higher spatial resolution). 

Polar orbiting satellites usually observe the same spot on Earth about twice per day. They also provide frequent coverage of polar regions, not visible from geostationary satellites.

Polar orbiting satellites collect essential data used in forecast models. Our atmospheric forecast model (ACCESS) uses data from about 30 polar orbiting satellites. The types of observations include:

• profiles of temperature and humidity
• winds at the surface of the Earth.

Some of the polar orbiting satellites that we use are from United States of America and European programmes.

Joint Polar Satellite System Programme (JPSS)

The Joint Polar Satellite System is the new generation of polar orbiting environmental satellites. This is a collaboration between the US National Oceanic and Atmospheric Administration (NOAA) and NASA.

There are 3 operational satellites:

• Suomi National Polar-orbiting Partnership (S-NPP), launched in 2011
• NOAA 20, formerly known as JPSS 1, launched in 2017
• NOAA-21, known as JPSS-2, launched in 2023.

As new satellites replace older ones, the combination of satellites we use constantly evolves.

EUMETSAT Polar System Programme (EPS)

The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) operates 2 meteorological operational satellites under its EPS Programme:

• MetOp B
• MetOp C.

These satellites carry several instruments that provide information on the 3-dimensional nature of the atmosphere:

• advanced microwave sounding unit (AMSU-A), to provide temperature profiles of the atmosphere
• advanced scatterometer (ASCAT), which uses microwaves to gather data on surface wind direction and speed
• infrared atmospheric sounding interferometer (IASI), to measure atmospheric temperature and humidity
• advanced very high resolution radiometer (AVHRR/3). This instrument measures reflected visible and near-infrared solar energy and radiated thermal energy from land, sea, clouds, and the intervening atmosphere.

Satellite ground station network

The Bureau operates a national-scale network of satellite ground station antennas at:

• Melbourne, Victoria
• Darwin, Northern Territory
• Learmonth, Western Australia
• Casey and Davis stations in Antarctica.

The receiving stations provide:

• low latency observations for forecast models
• national-scale information for many of our products for the Australian community.

We are also part of the Australian National Ground Segment Technical Team. This is a partnership with:

• Geoscience Australia
• Landgate – Satellite Remote Sensing Services
• CSIRO Space and Astronomy
• the Australian Space Agency.

Direct Broadcast Network (DBNet)

The Bureau is the South Asia-Pacific coordinator for the World Meteorological Organization (WMO)'s Direct Broadcast Network.

DBNet is part of the WMO's Space Programme. It aims to provide numerical weather prediction centres around the world with polar satellite products that have low data latency. This means that the products must arrive at all centres within 15–30 minutes after instrument sensing.

Our satellite receiving stations contribute data to this international effort.