Suitability for data aggregation at state and center level. Based on above criteria three projection systems viz. Polyconic , Transverse Mercator and Lambert conformal conic with two standard parallels are selected for the study. The UTM projection is not selected because of its limitation due to its Zonal characteristic to represent only 6 degree longitude by 8 degrees latitudes area. It introduces minimum distortions in shape , area, scale and direction near central meridian and distortions increase with respect to.
Local angles are accurate along the central meridian.
The scale along each parallel and along the central meridian is accurate. It increases along the meridians as the distance from the central meridian increases One reason for selecting this projection is that SOI topographic maps are prepared using Polyconic projection. Cylinder is kept longitudinal along meridian instead of along the equator. Small shapes are maintained but larger shapes are distorted while going away from the central meridian. Since UTM can not be considered for representing entire India his projection is selected for the study.