Towards Optical Maritime Surveillance with High-Altitude Platforms

Abstract

Increasing importance and growing needs for mon-itoring and surveillance of maritime areas are a big challenge,in particular facing current solutions. Conventional aircraft arelimited in operation time and range. Moreover, missions are cost-intensive for extended observations. Remote sensing satellites aresuitable for scanning large areas, but they cannot continuouslymonitor a certain region of interest due to its orbit movement.This gap is going to be closed in the next years byHigh AltitudePlatforms(HAP). HAPs are solar-powered unmanned aerialvehicles, which are capable to continuously operate for weeksor months at altitudes of between 15 and 20 kilometers. Thisenables long-term quasi-stationary applications while keeping theability to relocate the platform within a certain range and time.TheGerman Aerospace Center(DLR) researches and developssuch a stratospheric platform within an integrated joint project.This aircraft is designed with a wingspan of 27 meters and amaximum take-off weight of about 138 kilograms. It includes acompartment to carry operational payloads with a weight of upto 5 kilograms.This article presents a design of an integrated optical payloadsystem specially tailored to this undergoing development plat-form. The aim of this novel technology payload is to provide newapplications in the field of maritime remote sensing safety andsecurity. The payload fulfills general high-altitude operation re-quirements. Amongst others this comprises the operation within awide temperature spread between night / daylight conditions andthe on-board real-time image processing at a maximum powerconsumption of 70 watts in total.Requirements of a HAP-based optical payload system areshown. A design fulfilling these requirements and the commu-nication concept using both, the narrowband and broadbanddata link, are presented. Furthermore, AI image on-boardprocessing approaches and its application for maritime purposesare discussed