In this case study we investigate the source region of whistler-mode chorus located close to the geomagnetic equator at a radial distance of 4. 4 Earth radii. We use measurements from the four Cluster spacecraft at separations of less than a few hundreds of km. recorded during the geomagnetic storm of 18 April 2002. https://www.roneverhart.com/ASUS-VivoBook-X515-15-6-FHD-Laptop-Intel-Core-i5-1135G7-2-4-GHz-Intel-Iris-Xe-Graphics-16GB-DDR4-RAM-1TB-SSD-Windows-/