September 21, 2019 Markus Geldenhuys

Hexagons, Alpacas and Tomography

So maybe I am running out of creativity or I suffer from severe sleep deprivation. So tonight I will talk about our latest science flight and combine that with photos of the wildlife in Argentina. I know they don’t fit, but hey it’s my post … 😉

Tonight is a special night for us; we are flying Hexagons!!! You probably wonder why am I so excited about flying this oddly shaped flight pattern?! Once you know what we can do with such a flight pattern you will understand. (Or at least I will try to explain as best I can to try and make you as excited as I am.)

A hexagon allows us to measure one airmass from all angles. As our sensor is in a gimbal frame which we can control to move forwards and backwards (45° to 135°). This allows us to measure the same air parcel not only from all sides but also multiple times from all sides. This all provides us with the input to do a tomographic retrieval (in a sort-of similar way how they reconstruct your brain to find tumours and so forth). In short, this means that we can then portray our observations within this airmass in a 3-D way. Thus, viewing a circle of 500km in a 3-D way is any atmospheric observationalist (if such a word exists) dream! This is seeing patterns in the air that you normally can’t see … These structures are gold from a dynamical standpoint. You don’t have to rely on a model and worry about all the assumptions going into it, you don’t have to look at point or 2-D measurements and try to interpolate or imagine what is going on, you simply look at what’s in your 3-D field.

Now that everyone is excited about hexagons ;-), I leave the best for last… We will not only do one hexagon but repeat the same hexagon twice. This is to develop a new retrieval method, a temporal retrieval (retrieval of the wave changing in time, instead of with distance). The hexagons will then be rounded off by two cross-sections to utilise the LIDAR looking above the aircraft. We then will use the LIDAR to track the gravity waves propagating to 50km (according to the forecast, but we hope to see some up to 80km!!).

So here are a few random photos of the wildlife encountered up to now in Argentina. This includes alpacas (Guanakos), foxes, flamingos, seagulls and a sole. The ‘not-so-much wildlife’ includes sheep, Shepard dogs (really fluffy big ones) and cattle.

Tags: Allgemein
Last Modified: 16.03.2025