NASA Lidar Lasers to Map Earth's Forests in 3D

An artist's conception of the 3D maps of forest architecture that data from GEDI could produce.

Credit: NASA's Goddard Space Flight Center

A new laser instrument developed for the International Space Station is expected to generate incredible 3D maps of Earth's forests.

The instrument called Global Ecosystem Dynamics Investigation (GEDI) uses lidar, a special kind of laser technology, to create detailed 3D maps and measure the biomass of forests.

NASA has already launched a satellite designed to measure carbon dioxide in the atmosphere, but the new instrument, once launched, will allow scientists to estimate the total amount of carbon stored here on Earth inside trees.

"(GEDI) lidar will have a tremendous impact on our ability to monitor forest degradation, adding to the critical data needed to mitigate the effects of climate change," Patrick O'Shea, chief research officer at the University of Maryland, said in a statement.

Scientists already knew that trees absorb carbon. What scientists don't know is how much they store.

This is a problem because scientists can't predict how much extra carbon would escape into the atmosphere if a forest was destroyed or if planting new trees would be enough to offset the emissions.

"One of the most poorly quantified components of the carbon cycle is the net balance between forest disturbance and regrowth," Ralph Dubayah, the (GEDI) principal investigator at the University of Maryland, said in the same statement.

GEDI's lidar instrument works by shooting streams of light particles at the Earth that then reflect back and are picked up by a detector.

The time it takes the particles to reach Earth and bounce back is converted into a distance.

Every material that the light particles pass through on their journey leaves behind a "fingerprint" that the detector can read.

That means that light particles that pass through leafy tree canopies will look different than the particles that pass through branches or trunks. The unique markers will allow scientists to construct detailed 3D maps of forest architecture.

The lidar pulses will measure the height of trees to about a 3-foot (1 meter) accuracy and allow scientists to estimate the total biomass in a forest and how much carbon it's storing.

GEDI will have three lasers that will shoot out a total of 14 laser beams that will cover about 4 miles (6.5 kilometers). The team of engineers behind GEDI estimate that it will send out about 16 billion laser pulses every year.

Piers Sellers, deputy director of Goddard's Sciences and Exploration Directorate, said GEDI's data will be invaluable when it's combined with historic records of carbon levels collected by satellites like Landsat and MODIS which have been hovering over Earth for decades.

Scientists will also combine the 3D maps with images, maps and data collected from other satellites.

The ultimate goal is to create a database that will monitor changes in forests over time.

Scientists hope the combined data will reveal more about land use, biodiversity and climate change effects.

NASA officials estimate that engineers will complete GEDI by 2018. Once aboard the space station, it will scan most tropical and temperate forests between 50 degrees north and 50 degrees south latitude.

André Kuipers Reports progress on Soyuz Simulator

Always nice to manually fly the Soyuz module around the International Space Station and make a smooth docking.

 Astronauts practice with laser for range /speed between Soyuz and ISS. Just in case radar drops out. Soyuz has 2 sets of radar; KYPC (Koers) 1 and 2.

After 3 months back in the Soyuz simulator with my crew mates it feels like home.

Nice runs with my Soyuz crewmates today. Approaching and docking. And solving malfunctions of course.

Ultra high speed film - Femtoseconds

How fast an intense laser pulse can change the electrical properties of solids is revealed by researchers from Kiel University in the current edition of Nature (09.03.2011). Scientists in the team of Professor Michael Bauer, Dr. Kai Roßnagel and Professor Lutz Kipp from the Institute of Experimental and Applied Physics, together with colleagues from the University of Kaiserslautern and the University of Colorado in Boulder, U.S.A., are following the course of electronic switching processes which occur within fractions of a second (femtoseconds).


The results of their research may trigger future developments of custom-made and ultra fast opto-electronic components in order to increase data transmission rates or to accelerate optical switches, to name just one example of potential areas of application.

“These techniques that we have developed enables us to record films of extremely fast processes in a much more comprehensive manner than it was previously possible with similar techniques”, Bauer explains. “We are able to, for example, directly track phase transitions in solids or catalytic reactions on surfaces.”


To record the films, the Kiel scientists used ultra short flashes of light in the soft x-ray spectral region generated with a specific laser system. Bauer: “The amount of information gained from our pictures when played back in slow motion is vast.

We will get completely new insights into most relevant electronic properties of solids which are important for a variety of current and future technologies, for example, in telecommunications.”

The Christian-Albrechts-Universität zu Kiel (CAU) has proven international expertise as a North German research university in the field of nanosciences and surface science, for example, in the German Research Foundation’s Collaborative Research Centre 855 “Magnetoelectric Composites — Future Biomagnetic Interfaces”.

Furthermore, the CAU is applying for the current round of the Excellence Initiative with the excellence cluster “Materials for Life”.

Background information:

Femto means “one part in a thousand million million”. When, for example, molecules react with one another or when the switching states in electronic components change, processes at the atomic length scale are involved which take place on time scales of femtoseconds.

Ultra short laser pulses in the so-called “soft x-ray spectral region” — i.e. light with very short wavelengths — enables one to make snapshots of the electronic states which are transiently formed during a switching process, for example.

The shots are combined in series to deliver a film depicting such switching processes with a level of detail and a temporal resolution which could previously not be achieved.

Original Paper:
www.nature.com/nature under: 10.1038/nature09829

NASA and ESA Spacecraft to Conduct Massive Experiment With Lasers

NASA and ESA are planning to launch three spacecraft into orbit around the sun some three million miles apart, and then have them shoot lasers at each other, Popular Science reports.

You may want to stop for a moment and just bask in the coolness of that idea. Back yet? The purpose of this project will be to prove one last part of Einstein's theory of relativity: the existence of gravitational waves, or "huge ripples in time and space that flow outwards from the collision of huge celestial bodies like black holes," as the report said.

To do this, NASA and ESA will deploy LISA, the Laser Interferometer Space Antenna; it consists of three spacecraft that will fire lasers at each other and measure the relative positions of floating cubes of gold and platinum alloy--with a precision of 40 millionths of a millionth of a meter.

The project is set for launch in 2020.