Evaluation of geometrical parameters of buildings from SAR images

75 %
25 %
Information about Evaluation of geometrical parameters of buildings from SAR images

Published on February 19, 2014

Author: federicoariu



The aim of this study is to develop a tecnique able to support the retrieval of the buildings height from SAR images.
In particular, an automatic method, which allows to evaluate the orientation angle of buildings in respect to the projection on the ground of the flight line of the radar platform, has been developed.
The starting point was the algorithm output that allows to identify and extract from SAR images the double scattering contribution whose intensity is linked to the geometrical and electromagnetic parameters of the buildings.
On SAR images, the double scattering contributions turn out to be misaligned dots, so, before evaluating the slope of the straight line of double scattering, a linear regression operation was necessary, starting from the knowledge of the coordinates of each pixel belonging to the line of double scattering.
Given the prospective presence of outliers, the absolute deviation instead of the standard deviation has been used.


Summary  Introduction and goals  Models description  Developed algorithm  Results

SAR images Pros: • Image quality not depending on: Solar illumination Weather trends • Wide coverage area • High resolution Cons: • Need of processing data to obtain the image

Geometrical distorsions  Layover  Shadowing

Electromagnetic diffusion model Single scattering

Electromagnetic diffusion model Double scattering

EM scattering from buildings BW=Backscattering from Wall BR= Backscattering from Roof BG=Backscattering from Ground D= Double scattering T= Triple scattering Lr =Range size of Layover Sr =Range size of Shadow S= Shadow

Scattering model Double scattering 0 hl tan cos k 4 2 2 S pq 1 tan 2 sin 2 4 k cos 4 r 2 0 E0 2 ES 2 1 2 2 exp tan C ' ' (0) 2 2 θ: detector angle φ: building orientation angle in respect to the detector azimuth k: propagation constant σ2: standard deviation h: buildings height l: buildings length Spq: scattering matrix 2 2 sin 2 2 C ' ' (0)

Evaluation of orientation angle:usefulness  Geometrical knowledge  Geometrical and electromagnetic parameters retrieval

Height retrieval  Geometrical method: h Lr h cos S r cos :  Radiometric method h 0 a b 4 a k 2 where b l tan 2 S pq cos 1 tan 2 2 sin 4 k cos 2 2 1 2 2 C ' ' (0) exp tan 2 2 sin 2 2 C ' ' (0)

Double scattering line retrieval Scanning equiazimuth ith row M Ideal sinc Zero-Padding correlation Retrieval of maxima

Double scattering line analysis y=mx+q m=tanα The software returns coordinates and intensity of the dots forming the double scattering line.

Linear regression Yi Xi Given a cloud of sampled dots, the linear regression supplies the straight line that rounds best the trend of the cloud of dots. ui

Choosing the linear regression algorithm The chosen algorithm minimizes minimizza lo scarto assoluto. ABSOLUTE DEVIATION y x STANDARD DEVIATION

SAR images simulations: 512 x 512 SENSOR OVERVIEW Platform height h = 20 Km Platform speed v = 0.9 Km/s View angle θ = 28° Antenna dim(azimuth) L x SAR 8 .5 m Antenna dim (range) L rSAR 1 .5 m Carrier frequency f = 1.282 GHz Pulse duration τ = 1.9 μs Chirp pulse bandwidth Δf = 14 MHz Sampling frequency fsamp = 31 MHz Pulse repetition frequency p.r.f. = 350 Hz Azimuth resolution Δx = 2.5714 m Range resolution Δy = 10.3067 m

SAR images simulations: 512x512 sensor Simulation 1: φ = 10 φs = 15.0° Simulation 2: φ = 25 φs = 26.6°

SAR images simulations: ERS-1 C SENSOR OVERVIEW Platform height h = 775 Km Platform speed v = 6.7 Km/s View angle θ = 23° Antenna dim(azimuth) L x SAR 11 . 1 m Antenna dim (range) L rSAR Carrier frequency f = 5.3 GHz Pulse duration τ = 37.1 μs 1 .0 m Chirp pulse bandwidth Δf = 15.55 MHz Sampling frequency fsamp = 18.98 MHz Pulse repetition frequency p.r.f. = 1.68 kHz Azimuth resolution Δx = 3.9860 m Range resolution Δy = 19.9285 m

SAR images simulations: ERS-1 C sensor Simulation 1: φ = 10 φs = 10.1° Simulation 2: φ = 30 φs = 30.0°

Conclusions  Pros: • Good accuracy depending on the numbers of dots that belong to the line.  Cons: • Range of angles to be evaluate low.

Add a comment

Related presentations

Presentación que realice en el Evento Nacional de Gobierno Abierto, realizado los ...

In this presentation we will describe our experience developing with a highly dyna...

Presentation to the LITA Forum 7th November 2014 Albuquerque, NM

Un recorrido por los cambios que nos generará el wearabletech en el futuro

Um paralelo entre as novidades & mercado em Wearable Computing e Tecnologias Assis...

Microsoft finally joins the smartwatch and fitness tracker game by introducing the...

Related pages

Building Height Estimation from High Resolution SAR ...

Building Height Estimation from High Resolution SAR ... the building parameter in the image ... building geometrical structure. 5.3. Evaluation by ...
Read more

PIER M Online - Building Height Estimation from High ...

PIER M : Progress In ... on the building geometrical properties in the SAR ... structure prediction in the slant image plane. An evaluation function ...
Read more

Stochastic geometrical model and Monte Carlo optimization ...

... according to radar configuration and building parameters, ... buildings using polarimetric SAR images ... geometrical edge detector for SAR images.
Read more

Evaluation of the Geometric Accuracy of Automatically ...

Evaluation of the Geometric Accuracy of ... statistic leads to accuracy parameters for an automated city modelling ... for X- and P-Band SAR Images.
Read more

Quantitative structure–activity relationship - Wikipedia ...

Quantitative structure–activity relationship models ... geometric parameters) ... Evaluation of the quality of QSAR models ...
Read more

Geometric Shapes | ClipArt ETC - Educational Technology ...

The Geometric Shapes ClipArt ... There are also images of leaning ladders, buildings, ... The Star Polygons ClipArt gallery includes 33 images of star ...
Read more

Multifractal dimension and its geometrical terrain ...

... than the fractal dimension in describing geometrical ... also been used as a parameter to segment SAR images [8] ... and buildings).
Read more

Interpretation of InSAR mapping for geometrical structures ...

... Interpretation of InSAR mapping for geometrical ... especially at building locations different SAR ... the SAR acquisition parameters are ...
Read more

Multichannel SAR Interferometry based on Statistical ...

Multichannel SAR Interferometry ... TanDEM-X, SAR-Lupe or Cosmo-SkyMed) provide SAR images up to ... the GIS data are providing the 2D building footprints ...
Read more