Saab Automobile AB

About: Saab Automobile AB is a based out in . It is known for research contribution in the topics: Radar & Antenna (radio). The organization has 760 authors who have published 890 publications receiving 11811 citations.

Simulation and modeling of laser range profiling and imaging of small surface vessels

Abstract: The detection and classification of small surface targets at long ranges is a growing need for naval security. Simulations of a laser radar at 1.5 μm aimed for search, detect, and recognition of small maritime targets will be discussed. The data for the laser radar system will be based on present and realistic future technology. The simulated data generate signal waveforms for every pixel in the sensor field-of-view. From these we can also generate two-dimensional (2-D) and three-dimensional (3-D) range and intensity images. The simulations will incorporate typical target movements at different sea states, vessel courses, effects of the atmospheric turbulence and also include different beam jitter. The laser pulse energy, repetition rate as well as the receiver and detector parameters have been the same during the simulations. We have also used a high resolution (sub centimeter) laser radar based on time correlated single photon counting to acquire examples of range profiles from different small model ships. The collected waveforms are compared with simulated wave forms based on 3-D models of the ships. A discussion of the classification potential based on information in 1-D, 2-D, and 3-D data separately and in combination is made versus different environmental conditions and system parameters.

A model-based and automated approach to size estimation of embedded software components

Abstract: Accurate estimation of Software Code Size is important for developing cost-efficient embedded systems. The Code Size affects the amount of system resources needed, like ROM and RAM memory, and processing capacity. In our previous work, we have estimated the Code Size based on CFP (COSMIC Function Points) within 15% accuracy, with the purpose of deciding how much ROM memory to fit into products with high cost pressure. Our manual CFP measurement process would require 2,5 man years to estimate the ROM size required in a typical car. In this paper, we want to investigate how the manual effort involved in estimation of Code Size can be minimized. We define a UML Profile capturing all information needed for estimation of Code Size, and develop a tool for automated estimation of Code Size based on CFP. A case study will show how UML models save manual effort in a realistic case.

A 0.6–4.0 GHz RF-Resampling Beamforming Receiver With Frequency-Scaling True-Time-Delays up to Three Carrier Cycles

Abstract: True-time-delays (TTDs) enable wideband analog and hybrid beamforming by mitigating the beam squint problem. This letter reports a TTD beamforming receiver supporting delays up to three carrier-frequency cycles. The implementation is the first published work in which the delays scale with the carrier frequency. The scaling enables TTDs for large arrays at low-GHz frequencies where long delays are required due to $\lambda _{c}/2$ antenna spacing. The delays are implemented through delayed resampling of a passive mixer’s discrete-time output. Driving the mixers with pulse-skipped local oscillator (LO) signals allows the delay range to exceed one carrier cycle. A polyphase receiver structure prevents aliasing of noise and unwanted tones caused by LO pulse-skipping. Our prototype implementation demonstrates squint-free beamforming for an-800 MHz instantaneous RF bandwidth. The proposed TTD is efficient for large arrays since the power consumption per antenna is only 5–13-mW across the 0.6–4.0-GHz frequency range. The prototype was implemented in 28-nm FD-SOI CMOS, and the die area including bonding pads is only 1.2 mm2.

A Statistical Analysis for Wavelength-Resolution SAR Image Stacks

Abstract: This letter presents a clutter statistical analysis for stacks of wavelength-resolution synthetic aperture radar (SAR) images. Each image stack consists of SAR images generated by the same sensor, using the same flight track illuminating the same scene but with a time separation between the illuminations. We test three candidate statistical distributions for time changes in the stack, namely, Rician, Rayleigh, and log-normal. The tests results reveal that the Rician distribution is a very good candidate for modeling stack of wavelength-resolution SAR images, where 98.59% of the tested samples passed the Anderson–Darling (AD) goodness-of-fit test. Also, it is observed that the presence of changes in the ground scene is related to the tested samples that have failed in the AD test for the Rician distribution hypothesis.

Quadrifilar helix antenna

Abstract: A quadrifilar helix antenna (1) comprising a first and a second set of helical antenna elements (2 a– 5 a, 2 b– 5 b) symmetrically arranged around a longitudinal axis extending through the axial center of the antenna (1). The antenna (1) is excited from feeding points (2 c– 5 c) in a local ground plane at the bottom (6) of the antenna. The helical antenna elements (2 a– 5 a) of the first set are interconnected in respective top ends of the elements at the top (7) of the antenna. The bottom ends of the first set are in galvanic contact with the respective feeding points (2 c– 5 c). The antenna is characterized in that the top ends of helical antenna elements (2 b– 5 b) of the second set are arranged in an open circuit and remain unconnected. The bottom ends of the helical antenna elements (2 b– 5 b) of the second set each includes a connection (2 d– 5 d) to the local ground plane.