Weather Balloon Helps Measure Earth's Reflectivity
November 1, 2013

HyperSpectral Imager for Climate Science Makes First Weather Balloon Flight

Lee Rannals for - Your Universe Online

The amount of sunlight reflecting off of Earth’s atmosphere is a key measurement for better understanding climate change, and weather balloons could help advance data collection techniques even more.

NASA’s Earth Science Technology Office is supporting the development of the HyperSpectral Imager for Climate Science (HySICS). This instrument made its inaugural engineering balloon flight at the end of September, providing realistic, space-like conditions at a fraction of the cost of launching an instrument into space.

A 60-story tall balloon helped to take HySICS to an altitude of nearly 122,000 feet, which is far above the majority of Earth’s atmosphere. HySICS was able to make measurements of Earth, the sun and the moon during both daylight and night hours.

Data from this engineering flight will be used to improve the instrument over the next year and to help advance the science algorithms used to process the data. The imagers were able to collect radiance data for nearly half of its eight and a half hour flight, during which it also periodically calibrated itself by performing accurate radiance scans of the sun and moon.

“HySICS images scenes onto a single focal plane array at wavelengths between 350 and 2,300 nanometers, covering the extremely important solar and near infrared spectrum containing most of the sun’s emitted energy. Using only a single array allows HySICS to be smaller and lighter than many imagers, a feature necessary for cost-effective space-based Earth observing missions,” NASA said.

The space agency is planning another balloon flight for September 2014, during which HySICS will be able to collect the most accurate solar radiance measurements that have ever been made of Earth. The next test flight will also allow HySICS to make the highest accuracy radiance measurements of the moon, which will have great value to lunar calibrations for other instruments.

Data collected during these flights will help refine the instrumentation needed for radiance and other hyperspectral studies. HySICS is not only able to act as a space-based radiance testbed, but the instrument is able to be a great benefit to both the Earth and lunar science communities.

The European Space Agency’s GlobAlbedo project is also helping scientists map out the changes in Earth’s reflectivity. Changes on Earth’s surfaces can affect how much of the Sun’s energy is being absorbed, which can have an effect on Earth’s energy budget and ultimately impact our weather and climate.

Earth-observing satellites have helped provide measurements of solar radiance for years, but new technology could lead to better measurements than those currently available. Scientists will be able to use data from GlobAlbedo and HySICS to better predict processes like global warming.