Today is the 6th operational day on the trot. The aircraft has broken its record for number of flights on the run – 7 as of today.  Unfortunately for the last two days all the clouds have been at a long range from the radar.  Our scanning pattern starts with a surveillance scan at 1° elevation out to 300km range and then 12 scans from 2° up to 15°.  For the surveillance scan at this maximum range the beam is 5.2km wide so it’s providing information from a large volume of atmosphere and is only useful for identifying cloud locations but tells us nothing about the vertical structure. Additionally, due to the curvature of the earth, the centre of the beam is at an altitude of about 10km! So, we decided to change the scanning pattern to include another two surveillance scans, a lower one at 0.5° and one at 1.5°, to try to get a little bit more information at long range to help inform the aircraft.  The image below shows an example of what this gives us. It is vertical cross-section through clouds – think of taking a slice through a cake and being able to see the layers. It is still limited information, but better than the information from a single beam.

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