Design criteria for a multispectral, medium resolution, optical remote sensing system for nano-satellites

Abstract

ABSTRACT The use of small satellites has opened up new areas of opportunity enabling the use of this technology to solve problems with a high level of confidence at low cost for many areas including the remote sensing area. This paper presents the technical considerations for the design of a multispectral optical imaging system suitable for medium-resolution image acquisition working under the limitations of a small satellite, specifically a nano-satellite (satellite of less than 10Kg). The specifications of this kind of satellite platforms and how this affects the design considerations are discussed. The document describes a proposed design for the system and the applicability and potential use of such development. Keywords: nano-satellite, remote sensing, small satellites, camera medium-resolution 1. INTRODUCTION The remote sensing of a territory is a strategic activity for a country, both for the medium-term planning and for the supervision and monitoring of short-term contingencies; such as natural disasters, pollution, environmental assessment and management of water resources, agriculture and conserva tion of forest resources and protected areas, management of marine and fishery resources, cartography, topography, urban land, and so on. Due to the size of Mexico in both surface and territorial sea, a large number of satellite images and other remote se nsing information, important to perform studies related to our natural resources is required periodic ally. Unfortunately, these imag es are not always accessible in date, area or both, also the cost factor could be a limitation for have access to this imagery. In general all this limiting th e usability and impact of the available images but in another ha nd also open de problem to of fer solutions according to our national reality. 1.1 Nano-Satellites The start of the satellite development was based on the use of small satellites by the launching of the Sputnik, with the increase in launch capability and maturity of technological developments the size and complexity of satellites grew to dimensions never expected, currently there are satellites of mo re than 7000 Kg. However with the growth of this sector and its focus on the minimization of the risk as principal design consideration, the projects have grown in complexity and cost. This paradigm was challenged by a group of academics at the University of Surrey in the UK, led by Professor Sir Martin N. Sweeting, who proposed the use of COTS tech nology (Commercial-Off-the-Shelf) on a small platform and assuming that the risk is just one more factor but not the dominant, in order to be able to develop small satellites with and acceptable cost. The proposal grew to develop technology in what is no w one of the fastest growing niches in the aerospace sector. It was there we re proposed a nomenclature for classifying th e satellites based on their size, a table that also includes the associate cost is shown in Figure 1 [1]. The concept of Nano-satellites was developed in 1999 by Stanford University and Polytechnic State University San Luis Obispo in California under the name of CubeSat, [2]. Since th en, a lot of universities around the world have adopted this standard for the development of satellite projects as a mech anism for engaging accelerated in space activities. The most popular Cubesat format so far is called 1U which have a measuring of 10x10x10 cm and weighs maximum 1 kg, is