Soan Reservoir calculations

Here are some basic numbers about Soan reservoir size, using two different elevation data sets for accuracy and cross checking.

Both datasets are off by 10 meters in abosolute elevation at area of interest.
but it doesn't effect the capacity or functional design of project, because in both cases, entire volume of lake comfortably lies below the required elevation, i.e, Tarbela's dead level (420 meters) with upto 20 meters head available for transferring water from Tarbela to Soan.

SRTM DEM V4.1 (one used inside google earth)
The Shuttle Radar Topography Mission (SRTM) is an international research effort that obtained digital elevation models on a near-global scale from 56° S to 60° N,[2] to generate the most complete high-resolution digital topographic database of Earth prior to the release of the ASTER GDEM in 2009. SRTM consisted of a specially modified radar system that flew on board the Space Shuttle Endeavour during the 11-day STS-99 mission in February 2000, based on the older Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR), previously used on the Shuttle in 1994. To acquire topographic (elevation) data, the SRTM payload was outfitted with two radar antennas.[2] One antenna was located in the Shuttle's payload bay, the other – a critical change from the SIR-C/X-SAR, allowing single-pass interferometry – on the end of a 60-meter (200-foot) mast[2] that extended from the payload bay once the Shuttle was in space. The technique employed is known as Interferometric Synthetic Aperture Radar.

The elevation models are arranged into tiles, each covering one degree of latitude and one degree of longitude, named according to their south western corners. It follows that "n45e006" stretches from 45°N 6°E to 46°N 7°E and "s45w006" from 45°S 6°W to 44°S 5°W. The resolution of the raw data is one arcsecond (30 m), but this has only been released over United States territory. A derived one arcsecond dataset (with trees and other non-terrain features removed) covering Australia was made available in November 2011; the raw data are restricted for government use.[3] For the rest of the world, only three arcsecond (90 m) data are available.[4] Each one arcsecond tile has 3,601 rows, each consisting of 3,601 16 bit bigendian cells. The dimensions of the three arcsecond tiles are 1201 x 1201.

The elevation models derived from the SRTM data are used in Geographic Information Systems. They can be downloaded freely over the Internet, and their file format (.hgt) is supported by several software developments.

The Shuttle Radar Topography Mission is an international project spearheaded by the U.S. National Geospatial-Intelligence Agency (NGA) and the U.S. National Aeronautics and Space Administration (NASA).



ASTER GDEM
ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is a Japanese sensor which is one of five remote sensory devices on board the Terra satellite launched into Earth orbit by NASA in 1999. The instrument has been collecting superficial data since February 2000.

ASTER provides high-resolution images of the planet Earth in 14 different bands of the electromagnetic spectrum, ranging from visible to thermal infrared light. The resolution of images ranges between 15 to 90 meters. ASTER data are used to create detailed maps of surface temperature of land, emissivity, reflectance, and elevation.