The third dimension in GIS:The third dimension in GIS:Practical issues and Future trendsPractical issues and Future trends
Presented during CSI-2011 at Presented during CSI-2011 at Ahmedabad on 02 Dec. 2011Ahmedabad on 02 Dec. 2011
Dr. PK SrivastavaDr. PK Srivastava
MD, GeoSpatial Delhi LtdMD, GeoSpatial Delhi Ltd
OverviewOverview
• Definitions
• Data sources and examples
• Visualisation of elevation
Definition of heightDefinition of height
Direction of verticalDirection of vertical
Figure 8.2
Deflection of the verticalDeflection of the vertical
Data sources and examplesData sources and examples
• Global topography
• CartoDEM
• LunarDEM
• Laser mapping
Global topographyGlobal 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 OrientaleOrthoimage Color Coded DEM Contour Image
Strip width: 20 km Strip length: 65 km
Ortho-Image, DEM and Color Coded DEMOrbit Number: 798; DOP: 13 Jan. 2009
-8000 Km 8000 Km
Ortho DEM Color CodedDEM
Detailed View
0 3 Km
Height Range: - 4386 to + 4120 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 ElevationVisualisation of Elevation
• Cartographic presentations
• Contours
• Built up area models in GIS
Colorcoded Raster DEMColorcoded 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
888.40 890.32 891.78 891.38 892.78 893.81
887.50 889.10 890.36 890.21 893.47 892.57
884.75 887.85 888.45 887.78 890.40 892.59
885.35 886.12 884.35 886.52 891.54 894.75
888.37 887.30 886.67 888.55 898.40 895.54
5’
898.40 884.52 884.32 889.54 896.35 895.35
0’ 0’ 5’
Digital Elevation Models
893.81 891.78 892.78 890.32 891.38 888.4 888.40 890.32 891.78 891.38 892.78 893.81 893.47
892.57 890.36 890.21 889.1 887.5 887.50 889.10 890.36 890.21 893.47 892.57 892.59
894.75 890.898. 888.45 887.85 900 4 887.78 884.75 887.85 888.45 887.78 890.40 892.59 895.54 884.75
891.54 896.35 886.12 895
885.35 886.12 884.35 886.52 891.54 894.75 886.52 885.38 895.35 88.3 A 888.55 884.35 887.3
886.67 7 890 888.37 887.30 886.67 888.55 898.40 895.54 889.54
B 888.4
898.40 884.52 884.32 889.54 896.35 884.52 885
895.35 884.32 C
D Elevation grid 880
E 875
F 2
3 4 5 6 Extrusion of grid values
Digital Elevation Models
888.40 890.32 891.78 891.38 892.78 893.81
887.50 889.10 890.36 890.21 893.47 892.57 900
884.75 887.85 888.45 887.78 890.40 892.59 895
885.35 886.12 884.35 886.52 891.54 894.75
A 890 888.37 887.30 886.67 888.55 898.40 895.54
B 885
898.40 884.52 884.32 889.54 896.35 895.35 C
880 Elevation grid D
E 875
2 3 F 5 6
Continuous elevation surface
White modelWhite model
Generic modelGeneric model
Textured modelTextured model
• Gopaldas.avi
Shortcut to Gopaldas.avi.lnk
Thank YouThank You
Author can be contacted at [email protected]
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 kmOrbit No.:2714; DOP: 22-06-2009; 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) INSAT Meteorological Data Processing System(IMDPS)
IMDPS Activity ScheduleIMDPS 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) is completed : 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