Capturing images from space involves trade-off between multiple complementary and conflicting requirements and design choices. One of the major choices is between wider coverage area and finer resolution. To obtain very fine resolution the width of the coverage zone has to be small. On the other hand, images with wider coverage will have lower resolutions. One of the ways this incongruence is circumvented by modern satellites is the adoption of agile pointing maneuvers. While they serve the purpose of increasing the width of coverage with fine resolution cameras, they also enable larger dwell times for the energy collection devices to further enhance the resolution beyond its physical limitation. Such techniques, in combination with advanced energy collection methods and image processing algorithms are providing images with unprecedented resolutions from orbital heights.
Generally as the satellite moves in orbit, the ground below it also continuously changes. Hence the cameras will be scanning a contiguous stretch of land strip as it traverses along the track. But by continuously rotating the spacecraft in a controlled manner so as to keep pointing the camera towards a single region of interest the resolution and quality of images can be greatly enhanced.
The video shows one such imaging sequence. The satellite performs a series of maneuvers to point towards the areas of interest and capture high resolution images. Initially it is in its nominal orientation which maximises the solar power generation by pointing the solar panels towards the Sun. Then it orients itself towards the left of its track to focus and dwell on a preprogrammed region of interest. The it does the some for another region on its right. Following that, it again does the same on a location over its track. After completing this series of imaging, then it reverts back to its nominal orientation. All this sequence of reorientation is carried out by means of sophisticated navigation, guidance and control algorithms residing in the onboard computers.
The mission designers and algorithm developers of SpaceTech Orbital have versatile expertise in devising the required flight systems configuration, onboard software algorithms and ground processing systems that are required to achieve these types of complex objectives for numerous variety of satellite applications.