Terrestrial photogrammetric mapping of the Neh-Nar glacier in Himalaya, India

Terrestrial photogrammetry holds distinct advantages over the conventional theodolite survey or aerial photogrammetry for glacier surveys, on account of inaccessibility of upper reaches of the glaciers and non-suitability of large-scale aerial photography for very high relief areas. The Neh-Nar glacier was mapped with a contour interval of 10 m utilising terrestrial photogrammetric techniques because no large-scale base map of the glacier was available for detailed glaciological studies. This glacier was selected under the International Hydrological Programme. Apart from topographic details various features of glaciological significance like transient snowline, accumulation and ablation zones, bergschrund, icefalls etc., were also mapped.