Third World Satellite (TWSAT) is a small satellite of the Indian Space Research Organization (ISRO), weighing
approximately 100 kg. This spacecraft will carry a 37-meter ground resolution, four band multispectral optical payload.
This is a low cost, quick to develop, payload for studies of coastal regions, forestry, agriculture and related applications.
The payload features four identical lens assemblies, each of which is designed to operate in a particular spectral band by
using an appropriate band pass filter. The optical design is innovative in being usable over a spectral range of 450 to 860
nm. The design of the lens assembly is very compact, and as a result the payload is also small and commensurate with a
small satellite. This payload is expected to reduce cost drastically compared to previous payloads by using qualified,
commercial components to a large extent. The mechanical design of the payload features a monolithic, light weighted,
aluminum main structure. This structure supports the lens assemblies on one side, and the detector head assemblies on
the other side. This paper presents the optical and mechanical design of the electro-optic module, and the various tests
proposed to be carried out to qualify the payload for space use.
The Indian Remote Sensing (IRS) P5 spacecraft carried two identical optical payloads (Cartosat-1), each with a different view angle, for acquiring high resolution remote sensing data in stereo mode for the purpose of generation of topographic maps. Information on terrain height derived from these payloads is useful for applications in a number of forms including digital elevation model (DEM) creation, orthoimage, DEM plus thematic data and scientific visualization. Each optical payload features an unobscured, three-mirror anastigmat, design providing high contrast, and wide swath imagery. The mechanical design of the camera structure enabled accurate location of the mirrors while maintaining a very high degree of dimensional stability during launch and in-orbit environment. This paper presents the optical and mechanical design of the camera assembly as well as the alignment and performance optimization carried out in realizing the Cartosat -1 payload.
Conference Committee Involvement (2)
Earth Observing Missions and Sensors: Development, Implementation, and Characterization V
25 September 2018 | Honolulu, Hawaii, United States
Earth Observing Missions and Sensors: Development, Implementation, and Characterization IV