Cartographic Data Products:
The overview of the Cartosat-1 Data Products generation facility is given in
fig.3.1.
The main constituents of this facility are, 1) Data Archival and Quick-look Browser (DAQLB) Systems, 2) Data Processing System (DPS) and 3) Cartosat Data Centre (CDC). The CDC interfaces with the Cartosat user community in getting the user requirements and processes the archived or acquired data, making use of the sub-modules like Stereo Strip Triangulation (SST), the Ground Control Point Library (GCPL) and the Data Products and Services modules. The stereo strip triangulation subsystem takes the primary GCPs and the DLI as input and generates (1) Triangulated Control Points (TCP), (2) Coarse DEM and (3) Updated orientation parameters. The TCPs and coarse DEMs and the IMS work order are the inputs for data products generation subsystem along with DLTs for generation of Data Products operationally. Various types of Data products planned using Cartosat images are (1) Image Data Products, (2) Image Map Data Products and (3) DEM Data products. Various aspects of the Data products (and various resource generation like coarse DEM generation and Triangulated Control
Point (TCP) generations are briefly given below.
- Image Data Products:
The levels of Image Data Products defined on the basis of their indented end use with attended impact on accuracy and turn-around time, covering both stereo and monomode of operations is given in table 3.1. Different types of image data products meeting the targeted user needs are generated based on the spacecraft operational modes like stereo mode or mono mode and the orbit and attitude determination modes. Different types of products meeting the station specific user needs over the entire globe coverage is also planned for different earth stations and onboard SSR modes of data acquisition.
Table 3.1 Levels of Data Products
| Level of Product |
RadiometricCorrection |
Geometric Correction |
Intended End-Use. |
| Level '0A'RAW |
Not Applied |
Not Applied |
For internal use. |
| Level '0B'RAD |
Applied |
Not Applied |
For stereo processing at user end
/ VAS providers / DQE |
| Level '1'SYS |
Applied |
System Knowledge |
Quick turn-around-time digital products,
with acceptable quality for flat terrain or
mono mode data acquisition. |
| Level '2'GCP |
Applied |
System Knowledge + GCPs |
For better location accuracy for
cases when DEM is not available,
for data acquired in mono mode
or for flat terrain. |
| Level '3A'DEMA |
Applied |
System Knowledge + GCPs + DEM
(external input) |
Orthoimage products primarily for
IGS use, where GCPs and DEM are externally available. |
| Level '3B' DEMB |
Applied |
System knowledge+ GCPsDEM (internal) |
For Orthoimage product generation for data acquired in stereo mode. |
| Level '3C' DEMC |
Applied |
System Knowledge + GCPs + DEM
(external/internal,interactively edited
for density and surface
discontinuities) |
For precision Orthoimage / Orthoimage map generation/map updating. |