Development of a panoramic third generation IRST: initial study and experimental work

Abstract

The paper introduces the analysis carried out by Selex ES (SE) for the development of a third generation IRST system based on large format MWIR sensors, separable in blue and red bands. In the feasibility study, physical constraints have been evaluated relying on different optics and scanning options. The goal is a system based on distributed heads to cover 360 with a resolution better than 0.3 mrad and high frame rate that allow to take advantage of the typical atmospheric phenomena of the maritime environment as scintillation and super and sub refraction. Two critical aspects were investigated: (i) the setting of an adequate scanning mechanism to assure a high frame rate and (ii) the stitching of the collected images while maintaining the bit-depth so as to avoid abrupt changes of SNR at the seams between two subsequent images

Conceptual Design and Image Motion Compensation Rate Analysis of Two-Axis Fast Steering Mirror for Dynamic Scan and Stare Imaging System

“…The imaging FOV can be expanded by scanning of the gimbal. TDI mode can be used to improve the signal-to-noise ratio (SNR) and realize IMC [3,8,9].…”

“…In the surveillance/tracking mode, the camera can obtain the target image and trajectory in real time, which requires the aerial reconnaissance camera to have the characteristics of a high frame frequency and positioning accuracy [ 1 , 2 , 3 , 4 , 5 ]. There are four common aerial camera imaging modes: staring imaging, linear array scanning imaging, step and stare imaging, and dynamic scan and stare imaging [ 6 , 7 , 8 , 9 , 10 , 11 ]. The advantages and disadvantages of these imaging methods are shown in Table 1 .…”

Digital readout integrated circuit (DROIC) implementing time delay and integration (TDI) for scanning type infrared focal plane arrays (IRFPAs)

“…Infrared imaging technology has been developed first in the 1950s to be used in military surveillance systems and it has been a very useful tool for many military and civilian applications such as IR search and track [5] [6], medical examination [7], astronomy [8], forward-looking infrared (FLIR) systems [9], missile guidance [10], security [11], process control [12], environmental monitoring [13] and spectroscopy [14]. The main motivation for the IR technology was military demands at the beginning, and it is still the main driving force to develop high-performance IR detectors and imaging systems.…”

Non-Rotationally Symmetric Field Mapping for Back-Scanned Step/Stare Imaging System

“…The third-generation IRST systems utilize the FPAs with step/stare imaging to achieve wide area coverage. The new IRST achieves greater performances than the previous generation thanks to their staring nature, i.e., to longer integration times (milliseconds rather than microseconds) [3][4][5][6][7][8].…”

“…They also suffer from more false alarms [2].The third-generation IRST systems utilize the FPAs with step/stare imaging to achieve wide area coverage. The new IRST achieves greater performances than the previous generation thanks to their staring nature, i.e., to longer integration times (milliseconds rather than microseconds) [3][4][5][6][7][8].In step/stare imaging applications, a high-resolution narrow FOV sensor is rapidly stepped or indexed across an area of interest, stopping at intervals to stare and collect imagery. Then the images at each location are stitched together to form a large but high-resolution image.…”