Module hBG18

(INTERNAL) Quasi-geoid-heights from the "Belgian hybrid quasi-geoid: hBG18" for 48.5 <= lat <= 52.5 and 1 <= lon <= 7 at increments of 0.01 respectively 0.015 degrees.

See: C. Slobbe, R. Klees, H.H. Farahani, L. Huisman, B. Alberts, P. Voet, F. De Doncker (2018) "The Belgian hybrid quasi-geoid: hBG18. V. 1.0. GFZ Data Services" http://doi.org/10.5880/isg.2018.003