The third dimension in GIS: Practical issues and Future trends Presented during CSI-2011 at Ahmedabad on 02 Dec Dr. PK Srivastava MD, GeoSpatial Delhi Ltd

Overview Definitions Data sources and examples Visualisation of elevation

Definition of height

Direction of vertical

Deflection of the vertical

Data sources and examples Global topography CartoDEM LunarDEM Laser mapping

Global topography

National DEM from Cartosat-1 Study team considered three approaches : –Approach 1,2 COTS-based, –Approach 3 Indigenous (2006) using Augmented SST & High Density image matching (Approved) Refined specifications & Objective: ~10m DEM seamless homogenous with coregistered 2.5m orthoimage –Segment-based production (ASST) –Strip-level mosaicing –Quality Verification & Editing –Tile archival & Dissemination Ortho-Image Hilly Terrain Near Jammu DEM

DEM REPRESENTATION OF SONAMARG AREA IN SRINAGAR

Perspective view of Sonamarg

DEM generated for Himalayan region using new image matching algorithm LEGEND SSTS run using GCPS collected from neighboring segment Not processed Outside India Completed Note : SSTS in the southern generated using GCPL library (pink color in this region represents non availability of cloud free data )

LunarDEM and Lunar Mapping

Part of Mare Orientale OrthoimageColor Coded DEMContour Image Strip width: 20 km Strip length: 65 km

Ortho-Image, DEM and Color Coded DEM Orbit Number: 798; DOP: 13 Jan Km 8000 Km Ortho DEMColor Coded DEM Detailed View 0 3 Km Height Range: to m

LiDAR LiDAR is technology that uses lasers to measure objects Each beam hitting the ground returns the X, Y and Z (elevation) coordinate at that location Accuracy of each position is accurate within centimeters

Aerial coverage

LiDAR coverage

Visualisation of Elevation Cartographic presentations Contours Built up area models in GIS

Colorcoded Raster DEM

Hillshade Elevation raster with hillshade

Slope Slope identifies the steepest downhill slope for a location on a surface Higher the slope value, the steeper the terrain Slope can be expressed as degrees or percent Formula: Percent Slope = (Rise/Run) * 100 Slope approaches ∞ as the angle reaches 90° An example: 100’ (100/100) * 100 = 100% Slope 45° 100’

Percent slope Percent slope with hillshade

Slope Variations in color result from hillshade Percent slope with hillshade

Percent slope viewed in 3-dimensions Percent slope with hillshade

Aspect Defined Aspect is the direction that a slope or hill faces Potentially significant as a restoration tool to identify species appropriate for certain faces

Aspect Percent slope viewed in 3-dimensions Percent slope with hillshade

Aspect Percent slope viewed in 3-dimensions Percent slope with hillshade

Contours

Digital Elevation Models ’ ’ 5’

Digital Elevation Models A B C D Elevation grid 880 E 875 F Extrusion of grid values

Digital Elevation Models A B C 880 Elevation grid D E F 5 6 Continuous elevation surface

White model

Generic model

Textured model

Gopaldas.avi

Thank You Author can be contacted at

1,000,000 Graticule extent (LCC/TM) with 1 :250k Grids 1:1000,000 1:250,000 Polar Stereographic Projection for latitudes between 70 and90

Typical Chandrayaan-1 Topo Ortho-image Map

Part of PLASKETT Crater Viewed by Chandrayaan-1 TMC from 200 km Orbit No.:2714; DOP: ; Ascending FORE NADIRAFT Detailed View 0 4 Km

Mandate - To Design, Develop, Procure and Integrate Hardware and Software for a complete INSAT Data Processing facility at IMD, Delhi KALPANA-1 & INSAT- 3A ( VHRR & CCD) Installed and operational at BES & IMD on 24 x 7 (SAT Completed) Data Acquisition and Quick Look Display Data Products Generation Geophysical Parameters (AMV,OLR,UTH,QPE,CMV/WVWV, SST, AOD, NDVI) INSAT Meteorological Data Processing System(IMDPS)

IMDPS Activity Schedule INSAT 3D Design Review for DAQLS and DP elements: Jan 2007 ATBD for 21 Geo-physical parameters completed : Mar 2007 Discussion on GPR (with IMD) iscompleted : Dec 2008 All Procurements of Target Hardware including SIDS : Completed  Hardware Shipment to IMD (DAQLS, DPPR): Completed  DAQLS (K1,3A): Completed  UPS Installation at IMD : Completed  Networking at IMD : Completed  System Procurement & Installation at IMD: Completed Infrastructure Readiness at IMD: Ready Algorithm Theoretical Basis Definition (ATBD) : Completed Design Review & Prototype development : Completed INSAT 3D Software Development : In final stages Factory Acceptance (FAT) at SAC: Completed System Integration and SAT (K1,3A): Completed Software & Hardware Training : completed Operationalization at IMD (24 x 7): Completed (K1 & 3A) SAT at IMD with INSAT-3D: Launch + 6 Months GP Products Validation : 3A/K1 : In Progress

Switch to Demo of Terrain visualisation This software is developed in-house by carrying out low level programming of graphics card as a visualisation and analysis tool