Full HTML for
Given by Deepak Ramanathan at Rome Lab Quarterly Review for CIV on October 1 96. Foils prepared 22 February 97
Outside Index
Summary of Material
| Dataset Requirements |
| Digital Elevation Models |
| Satellite Imagery |
| Census data |
| Handling the Data |
Denote Foils where Image Critical
Denote Foils where HTML is sufficient
Database Support for GIS Application
Dataset Requirements
Digital Elevation Models
Satellite Imagery
Census data
Handling the Data
Conclusions
Outside Index
Summary of Material
HTML version of Basic Foils prepared 22 February 97 
Full HTML Index
| Deepak Ramanathan |
HTML version of Basic Foils prepared 22 February 97
Full HTML Index
For providing 3-D terrain rendering, the following datasets were needed:
|
| These data were identified as being either in Public Domain or needed to be purchased from commercial organizations. |
| Data was evaluated from both these resources. |
HTML version of Basic Foils prepared 22 February 97 
Full HTML Index
| A DEM consists of a sampled array of elevations for a number of ground positions that are normally at regularly spaced intervals. These intervals determine the spatial resolution of the DEM. |
| The USGS offers DEM in Public Domain having a spatial resolution of 90 m whereas commercial organizations have the DEM's at 30 m. This is a marked improvement over USGS data. |
HTML version of Basic Foils prepared 22 February 97
Full HTML Index
| Satellite imagery needs to be of high spatial resolution owing to the visual nature of the CIV project. |
| Currently the highest spatial resolution available is 5 m obtained by the IRS-1C satellite. This is the finest spatial resolution offered by a non-military satellite. |
| The data would consist of a 70km x 70 km swath of the region of interest. |
| This would be enhanced with merging techniques that would impart color to the image based on visible wavelength bands. |
| Very expensive.... |
HTML version of Basic Foils prepared 22 February 97
Full HTML Index
The topological structure of the Census TIGER database defines
|
This data is freely accessible to the public, and
|
The Census database also includes
|
HTML version of Basic Foils prepared 22 February 97
Full HTML Index
A large percentage of the data is static.
|
| For visually appealing terrain rendering, it is imperative that data having high spatial content be obtained. |
| Public Domain data lacks the spatial resolution that the project demands. |
| Commercial data, when used, has been found to meet these requirements. In the case of satellite imagery, commercial data is the only reasonable alternative. |
HTML version of Basic Foils prepared 22 February 97
Full HTML Index
| NPAC will aquire samples of commercial data for DEM and satellite imagery |
| We will build local databases replicating public domain data in a format suitable for the project |
| Data covering the entire scenario area can only be aquired by the funding agency |