This panorama has been shot handheld with the innovative Sony ILCE-QX1 ‘camera’. I took one image in each cardinal direction and an extra shot for zenith and nadir. I held the camera obove my head to reach a higher view point and released using my smart phone. For a more detailed description of the setup see this post from PanoTwin Jürgen.
The maximum equirectangular panorama size of this setup is about 10000×5000 pixel according to PTGui. However the one you see below has been downsized to 6000×3000 pixel before publishing it on Google Views.