BGU | The Sky is No Limit

for the loan of NASA instruments for monitoring the components of the atmosphere, and the other supported joint research activity in Israel. Instruments worth hundreds of thousands of dollars were shipped from the US to Karnieli’s lab in Sde Boker, enhancing remote sensing research across the University. The agreement has since been renewed and extended every few years and several of those original instruments are still operating today as part of a global atmospheric monitoring network, studying climate change and more. In addition, NASA scientists participated in two large-scale field experiments, which included ground and aerial measurements, conducted in the Negev in the 1990s. They included testing a sun photometer prototype used to measure atmospheric particles in the summer of 1993. In 1995, a finished device was permanently placed on the Sde Boker campus. The photometer transmits atmospheric data to NASA once every ten minutes, and has since featured in countless studies, including, for example, monitoring a powerful dust storm that covered Israel between September 5 and 8, 2015. Nowadays, the Remote Sensing Lab is busy with data sent by VENμS (Vegetation and Environment monitoring New Micro-Satellite), a first of a kind cooperation between the Israeli and French space agencies. VENμS, whose scientific mission is spearheaded by Ben-Gurion University, is dedicated to monitoring vegetation on the Earth’s surface using a super-spectral camera and was built entirely by the local aerospace industry. It was launched into orbit in 2017 and remains active to this day. " VENμS is a unique satellite," explains Karnieli. "We receive the images every 48 hours in 12 wavelengths with a spatial resolution of 4 meters. The amount of information and volume of the digital data we receive are enormous." These images undergo processing and cataloguing before being shared with scientists around the world. "I am very pleased with the significant number of scientific articles published in leading journals, and especially

those that prove VENμS’s advantage over other satellites of its type that are operated by larger, better funded space agencies," Prof. Karnieli notes. Remote sensing is an effective tool in supporting sustainable agriculture in the face of increasing global food demand, while at the same time minimizing agricultural inputs. The application of remote sensing to precision agriculture, for example, allows growers to identify anomalies in their field, orchard, or vineyard almost instantly. "The goal of research using remote sensing applications for precision agriculture is to ensure the collected data does not just remain in the laboratory. The high spatial resolution and consistency of observations make it possible to identify a range of potential problems, such as damage to irrigation pipes or pests, and to inform farmers of their exact location so they can precisely control the application of irrigation, pesticides or fertilizer to the area in question,” says Karnieli. The laboratory is also involved in the analysis of satellite data about compromised ecosystems. For example, the effect of the oil leak in the Evrona Nature Reserve in 2014, the contamination of Nahal Ashalim by acidic effluents following the collapse of a containment pool at a fertilizer plant in 2017, or tar buildup on the beaches following oil spills at sea. It also helps detect and monitor fires in forests and agricultural fields, as well as measure environmental and functional remediation in their aftermath. Prof. Karnieli believes that the future lies in satellites: "Some are synchronized, working and communicating in concert to ensure continuous coverage, at different wavelengths and different resolutions, of every point on the Earth’s surface. This vast amount of data, which continues to grow every day, requires tremendous computing resources, innovative processing methods, and the involvement of scientists who specialize in computer learning and analysis. We have come a long way: from just two satellites in orbit at the beginning of my journey as a young scientist, there are now thousands.”

Thermal Imaging Reveals Discrepancies

along the Egyptian Border

Prof. Arnon Karnieli had already spent years studying the spatial and temporal shifting of sand in the northern Negev, when he noticed that the sand in the Negev appeared to be darker than the sand in northern Sinai, just across the border. He was particularly surprised by how clearly the contrast along the Egypt-Israel border was reflected in thermal measurements: “One day I was looking at thermal satellite images we received at the station and realized that the Negev sand was four degrees warmer than the sand in Sinai. This was astonishing because the border between Israel and Egypt is just a political line. The two sides are actually very similar in terms of their geomorphology, soil and climate, so these differences in color and temperature should not exist.” Karnieli’s subsequent research revealed that the contrast can be ascribed to human activity. The Negev side of the border is primarily a nature reserve, where a relatively dark crust of topsoil has remained largely undisturbed. On the Egyptian side, there is much more human activity, including intensive grazing, which has eroded the crust and exposed the lighter-colored sand beneath. The darker crust emits greater heat than the exposed lighter sand.

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