add a short circuit for empty detector list in demodulation
fix atmospheric snapshot output for debugging
noise estimator will automatically create the output directory if it does not exist
and some bigger items:
the three concentric atmospheric cones are now scaled to fit the specified zmax so we don't simulate useless volume elements. This change means that old and new atmospheric simulations will be incompatible.
Volume element size (xstep, ystep, zstep) is now defined in terms of the largest, not the smallest concentric cone. This is more intuitive since it is the same length scale as the total simulated volume.
fixed broken snapshot plot generation in atmospheric simulation
Small tweaks that didn't deserve a separate PR:
zmaxso we don't simulate useless volume elements. This change means that old and new atmospheric simulations will be incompatible.xstep,ystep,zstep) is now defined in terms of the largest, not the smallest concentric cone. This is more intuitive since it is the same length scale as the total simulated volume.