The challenge for still unresolved development of multi-band equatorially orbiting POLSAR satellite sensors — An integral task for the major space-SAR technology centers world-wide

With the relentless increase in population density, the anthropogenic expansion into natural terrestrial hazard zones has become irreversible resulting in ever more catastrophic disasters especially within the entire tropical belts engulfing Mother Earth. What is required is around-the-clock local and wide-area surveillance and remote sensing of the vegetative cover for which hitherto well designed optical equatorially orbiting satellite sensors had been developed but their successful implementation is failing ever more because of the ever increasing cloud, precipitation, humidity and increasing aerosol cover within the entire equatorial belt of +/- 15* - 20* latitude rendering penetration at optical wavelength mostly ineffective. Hence, recourse must be taken of active microwave sensing, and implementing radar and synthetic aperture sensors from air and space operational at day & night and which are mainly independent of weather: The sensors especially suited are the fully polarimetric POLSAR sensors developed for satellite remote sensing by the major SAR technology development centres worldwide. The challenge is thus to develop equatorially orbiting SAR, preferably wide-swath POL-SAR satellite sensors, within the desirable P/L/S/C/X/Ka multi-bands by implementing novel beam-steering radar for wide-swath high-resolution coverage. Therefore, we need to mobilize and draw full responsible attention of the main SAR Development Centres and its supporting organizations worldwide in order for realizing the challenging proposal.