Radar altimeters

"It is commonly understood that an altimeter is a down-looking radar device designed to measure relative altitude, thus to establish the height of the radar above the surface below. Although similar in form and function, the purpose of a remote-sensing altimeter is different, since usually it is mounted on a spacecraft whose orbital height is known. Remote-sensing altimeters are designed to retrieve certain geophysical parameters about the surface from the timing and shape of the radar reflections (waveforms)." (Raney, Keith. 2014)
 

Sources

Raney, Keith. 2014. “Radar, Altimeters.” In: Njoku E.G. (eds) Encyclopedia of Remote Sensing. Encyclopedia of Earth Sciences Series, 525–32. https://doi.org/10.1007/978-0-387-36699-9_134.
 

Related Content

Article

Monitoring hydrological changes from space in a sparse gauged basin

Monitoring hydrological changes from space in a sparse gauged basin

Satellites that measure water related parameters and orbit around the Earth

Africa is endowed with abundant freshwater resources. It has sufficient rainfall and relatively low levels of water withdrawals for three major uses: domestic, agricultural and industrial uses. Changes in Africa’s water resources has been noticed transpiring in changes in water flow and variability, falling groundwater levels, changes in rainfall levels and timing, strongly influenced under climate change. The continent has a huge potential for energy production through hydropower.

Read More

A global eye on water: What the SWOT mission reveals about Earth’s water

A global eye on water: What the SWOT mission reveals about Earth’s water

SWOT Capturing the Yukon River in Alaska

From Nile floods to satellites: Humanity’s long quest to measure water

For as long as people have lived near rivers and seas, we have watched the water, measured it and tried to understand it because our survival depended on it. In fact, ancient Egyptians built nilometers along the Nile more than 5,000 years ago to predict floods while in China early engineers estimated the speed of rivers with floating objects. In Europe thinkers like Leonardo da Vinci designed new ways to track river flow.

Read More

Monitoring hydrological changes from space in a sparse gauged basin

Monitoring hydrological changes from space in a sparse gauged basin

Satellites that measure water related parameters and orbit around the Earth

Africa is endowed with abundant freshwater resources. It has sufficient rainfall and relatively low levels of water withdrawals for three major uses: domestic, agricultural and industrial uses. Changes in Africa’s water resources has been noticed transpiring in changes in water flow and variability, falling groundwater levels, changes in rainfall levels and timing, strongly influenced under climate change. The continent has a huge potential for energy production through hydropower.

Read More

Seguimiento de los cambios hidrológicos desde el espacio en una cuenca escasamente medida

Seguimiento de los cambios hidrológicos desde el espacio en una cuenca escasamente medida

The role of space technologies in integrated water resources management      

The role of space technologies in integrated water resources management      

Corn field

On a sweltering summer day along the banks of the Mekong River, villagers in Laos watched nervously as water levels fell dramatically. Upstream, hydropower dams in China had altered the river’s flow, leaving communities downstream scrambling for water to irrigate crops, sustain fisheries, and meet drinking needs. This scene is far from unique. Across the world, transboundary rivers are flashpoints of tension, where one country’s energy or agricultural ambitions can ripple downstream, affecting millions of people (UNESCO 2023). Global water stress is escalating at an unprecedented pace.

Read More