Dr Raffaella Guida

Research Interests

  • Microwave remote sensing
  • Synthetic Aperture Radar (SAR)
  • Scattering models from natural and not natural targets
  • Statistical models for SAR images
  • Main applications: urban areas, natural disasters (flooding, earthquake, oil spill), vegetation, maritime surveillance

Research Collaborations

Raffaella has a huge network of international collaborations with universities, space agencies, space and remote sensing companies and non-governmental organizations.

Teaching

  • Satellite Remote Sensing
  • Laboratories, Design and Professional Studies I
  • Laboratories, Design and Professional Studies II

For her excellence in teaching and keen attitude to introduce new teaching methodologies, Raffaella has been awarded the Teaching with New Technologies (TeNT) Award by University of Surrey in 2008.

Departmental Duties

  • Member of the Student Liaison Committee (SLC)
  • Member of the Faculty Research Degrees Committee (FRDC)
  • FRDC representative on the Postgraduate Research Student Engagement Forum
  • Rep for the Electronic Engineering Library

Affiliations

Raffaella is a member of the IEEE Geoscience and Remote Sensing Society.

PhD Programme

Possible work areas and topics

Earth observation
  • Urban areas monitoring with high resolution SAR images
  • UK forests monitoring with optical, infrared and radar imagery
  • Carbon stocks mapping
  • SAR polarimetry for land mapping
  • Maritime surveillance
  • Mines detection with remote sensing imagery
  • Remote sensing data fusion over urban areas
Disaster monitoring
  • Detection of flooded areas with optical and SAR images
  • Detection of damaged urban areas after earthquake in SAR images
Technology
  • S-band SAR

Requirements

You hold a first class honours degree in Engineering, Physics or Maths. You have knowledge of Remote Sensing and interest in Earth Observation and Disaster Monitoring, together with familiarity with at least one of the following fields: Electromagnetics, Image Processing, Geographical Information Systems (GIS).
Creative and hard-working profiles are particularly encouraged.

Other skills

Experience with IDL and/or ENVI software is an advantage.

Contact Me

E-mail:
Phone: 01483 68 2227

Find me on campus
Room: 25 BA 01


My office hours

9am-5pm

Publications

Highlights

  • Khan SS, Guida R. (2014) 'On Fractional Moments of Multilook Polarimetric Whitening Filter for Polarimetric SAR Data'. IEEE IEEE Transactions on Geoscience and Remote Sensing, , pp. 3502-3512.
  • Khan SS, Guida R. (2014) 'Application of Mellin Kind Statistics to Polarimetric G Distribution for SAR Data'. IEEE IEEE Transactions on Geoscience and Remote Sensing, , pp. 3513-3528.

    Abstract

    The ${cal K}$ distribution can arguably be regarded as one of the most successful and widely used models for radar data. However, in the last two decades, we have seen tremendous growth in even more accurate modeling of radar statistics. In this regard, the relatively recent ${cal G}^{0}$ distribution has filled some deficiencies that were left unaccounted for by the ${cal K}$ model. The ${cal G}^{0}$ model, in fact, resulted as a special case of a more general model, the ${cal G}$ distribution, which also has the ${cal K}$ model as its special form. Single-look and multilook complex polarimetric extensions of these models (and many others) have also been proposed in this prolific era. Unfortunately, statistical analysis using the polarimetric ${cal G}$ distribution remained limited, primarily because of more complicated parameter estimation. In this paper, the authors have analyzed the ${cal G}$ model for its parameter estimation using state-of-the-art univariate and matrix-variate Mellin-kind statistics (MKS). The outcome is a class of estimators based on the method of log cumulants and the method of matrix log cumulants. These estimators show superior performance characteristics for product model distributions such as the ${cal G}$ model. Diverse regions in TerraSAR-X polarimetric synthetic aperture radar data have also been statistically analyzed using the ${cal G}$ model with its new and old estimators. Formal goodness-of-fit testing, based on the MKS theory, has been used to assess the fitting accuracy between different estimators and also between the ${cal G}$, ${cal K}$, ${cal - }^{0}$, and Kummer-${cal U}$ models.

  • Brett PTB, Guida R. (2013) 'Earthquake Damage Detection in Urban Areas using Curvilinear Features'. IEEE IEEE Transactions on Geoscience and Remote Sensing,
    [ Status: Accepted ]

    Abstract

    Bright curvilinear features arising from the geometry of man-made structures are characteristic of synthetic aperture radar (SAR) images of urban areas, particularly due to double-reflection mechanisms. An approach to urban earthquake damage detection using double-reflection line amplitude change in single-look images has been established in previous literature. Based on this method, this paper introduces an automated tool for fast, unsupervised damage detection in urban areas. Ridge-based curvilinear features are extracted from a preevent SAR image, and double-reflection candidates are selected using prior probability distributions derived from a simple geometrical building model. The candidate features are then used with the ratio of a pair of single preevent and postevent SAR single-look amplitude images to estimate damage levels. The algorithm is very efficient, with overall computational complexity of $O(Nlog k)$ for an $N$-pixel image containing features of mean length $k$. The technique is demonstrated using COSMO-SkyMed data covering L'Aquila, Italy, and Port-au-Prince, Haiti.

  • Khan SS, Guida R. (2012) 'On Single-look Multivariate G Distribution for PolSAR Data'. IEEE IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 5 (4), pp. 1149-1163.
  • Guida R, Iodice A, Riccio D. (2010) 'Assessment of TerraSAR-X Products with a New Feature Extraction Application: Monitoring of Cylindrical Tanks'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE T GEOSCI REMOTE, 48 (2), pp. 930-938.
  • Guida R, Iodice A, Riccio D. (2010) 'Height Retrieval of Isolated Buildings From Single High-Resolution SAR Images'. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 48 (7), pp. 2967-2979.
  • Guida R, Iodice A, Riccio D, Stilla U. (2008) 'Model-Based Interpretation of High-Resolution SAR Images of Buildings'. IEEE IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 1 (2), pp. 107-119.

    Abstract

    High-resolution (HR) synthetic aperture radar (SAR) images of urban areas reveal a large variety of details that, although potentially bringing a lot of information, are often very difficult to interpret. Until now, most of the research activity in this field has been devoted to the attempt to retrieve geometric information on buildings in terms of their positions and sizes, by using simplified geometrical models. However, this approach does not allow us to fully exploit the large amount of information present in HR SAR images. In order to improve information retrieval from such images, and, hence, their interpretation, in this paper, we propose to employ a more refined model that accounts for both geometrical (including fine details) and electromagnetic properties of the building. A meaningful case study is presented to show that the main features appearing on the SAR image of a building can be interpreted by using our geometric and electromagnetic model. In addition, a first example of retrieval of the complex dielectric constant of building materials from a SAR image is presented.

  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G. (2004) 'Efficient Simulation of hybrid stripmap/spotlight SAR raw signals from extended scenes'. IEEE IEEE Transactions on Geoscience and Remote Sensing, 42 (11), pp. 2385-2396.

    Abstract

    The hybrid stripmap/spotlight mode for a synthetic aperture radar (SAR) system is able to generate microwave images with an azimuth resolution better than the one achieved in the stripmap mode and a ground coverage better than the one of the spotlight mode. In this paper, time- and frequency-domain-based procedures to simulate the raw signal in the hybrid stripmap/spotlight mode are presented and compared. We show that a two-dimensional Fourier domain approach, although highly desirable for its efficiency, is not viable. Accordingly, we propose a one-dimensional (1-D) range Fourier domain approach, followed by 1-D azimuth time-domain integration. This method is much more efficient than the time-domain one, so that extended scenes can be considered. In addition, it involves approximations usually acceptable in actual cases. Effectiveness of the simulation scheme is assessed by using numerical examples.

Journal articles

  • Iervolino P, Guida R . (2017) 'A Novel Ship Detector Based on the Generalized-Likelihood Ratio Test for SAR Imagery'. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10 (8), pp. 3616-3630.

    Abstract

    Ship detection with synthetic aperture radar (SAR) images, acquired at different working frequencies, is presented in this paper where a novel technique is proposed based on the generalized-likelihood ratio test (GLRT). Suitable electromagnetic models for both the sea clutter and the signal backscattered from the ship are considered in the new technique in order to improve the detector performance. The GLRT is compared to the traditional constant false alarm rate (CFAR) algorithm throughMonte–Carlo simulations in terms of receiver operating characteristic (ROC) curves and computational load at different bands (S-, C-, and X-). Performances are also compared through simulations with different orbital and scene parameters at fixed values of band and polarization. The GLRT is then applied to real datasets acquired from different sensors (TerraSAR-X, Sentinel-1, and Airbus airborne demonstrator) operating at different bands (S-, C-, and X-). An analysis of the target-to-clutter ratio (TCR) is then performed and detection outcomes are comparedwith an automatic identification system data when available. Simulations show that the GLRT presents better ROCs than those obtained through the CFAR algorithm. On the other side, results on real SAR images demonstrate that the proposed approach greatly improves the TCR (between 22 and 32 dB on average), but its computational time is 1.5 times slower when compared to the CFAR algorithm.

  • Iervolino P, Guida R, Whittaker P. (2016) 'A Model for the Backscattering from a Canonical Ship in SAR imagery'. IEEE IEEE Transactions on Geoscience and Remote Sensing, 9 (3), pp. 1163-1175.

    Abstract

    Synthetic aperture radar (SAR) sensors represent one of the most effective means to support activities in the sector of maritime surveillance. In the field of ship detection, many SAR-based algorithms have been proposed recently, but none of them has ever considered the electromagnetic aspects behind the interactions of SAR signals with the ship and surrounding waters, with the detection step and rate strongly influenced by relative thresholding techniques applied to the SAR amplitude or intensity image. This paper introduces a novel model to evaluate the radar cross section (RCS) backscattered from a canonical ship adapted, to the case at issue, from similar existing models developed for, and applied to, urban areas. The RCS is modeled using the Kirchhoff approximation (KA) within the geometrical optics (GO) solution and, following some assumptions on the scene parameters, derived by empirical observations; its probability density function is derived for all polarizations. An analysis of the sensitiveness of the RCS to the uncertainty on the input scene parameters is then performed. The new model is validated on two different TerraSAR-X images acquired in November 2012 over the Solent area in the U.K.: the RCS relevant to several isolated ships is measured and compared with the expected value deriving from the theoretical model here introduced. Results are widely discussed and ranges of applicability finally suggested.

  • Khan SS, Guida R. (2014) 'On Fractional Moments of Multilook Polarimetric Whitening Filter for Polarimetric SAR Data'. IEEE IEEE Transactions on Geoscience and Remote Sensing, , pp. 3502-3512.
  • Khan SS, Guida R. (2014) 'Application of Mellin Kind Statistics to Polarimetric G Distribution for SAR Data'. IEEE IEEE Transactions on Geoscience and Remote Sensing, , pp. 3513-3528.

    Abstract

    The ${cal K}$ distribution can arguably be regarded as one of the most successful and widely used models for radar data. However, in the last two decades, we have seen tremendous growth in even more accurate modeling of radar statistics. In this regard, the relatively recent ${cal G}^{0}$ distribution has filled some deficiencies that were left unaccounted for by the ${cal K}$ model. The ${cal G}^{0}$ model, in fact, resulted as a special case of a more general model, the ${cal G}$ distribution, which also has the ${cal K}$ model as its special form. Single-look and multilook complex polarimetric extensions of these models (and many others) have also been proposed in this prolific era. Unfortunately, statistical analysis using the polarimetric ${cal G}$ distribution remained limited, primarily because of more complicated parameter estimation. In this paper, the authors have analyzed the ${cal G}$ model for its parameter estimation using state-of-the-art univariate and matrix-variate Mellin-kind statistics (MKS). The outcome is a class of estimators based on the method of log cumulants and the method of matrix log cumulants. These estimators show superior performance characteristics for product model distributions such as the ${cal G}$ model. Diverse regions in TerraSAR-X polarimetric synthetic aperture radar data have also been statistically analyzed using the ${cal G}$ model with its new and old estimators. Formal goodness-of-fit testing, based on the MKS theory, has been used to assess the fitting accuracy between different estimators and also between the ${cal G}$, ${cal K}$, ${cal - }^{0}$, and Kummer-${cal U}$ models.

  • Iervolino P, Guida R, Iodice A, Riccio D. (2014) 'Flooding water depth estimation with high-resolution SAR'. IEEE Transactions on Geoscience and Remote Sensing, 53 (5), pp. 2295-2307.

    Abstract

    © 1980-2012 IEEE.The retrieval of flooding levels with high-resolution (HR) synthetic aperture radar (SAR) images is presented in this paper. A new framework is proposed. It is based on the inversion of theoretical scattering models initially developed for nonflooded urban areas and here adapted to the flooding case. Starting from the theory, two possible retrieval approaches have been developed and are the main topic of this paper: two possible retrieval approaches have been developed and are the main topic of this paper: the local Single Image Objects Aware (SIObA) and the global Two Image Area Aware (TIArA). These two approaches are conceived to be applicable under different working conditions and consequently holding different properties and reliability. For each of them, a different algorithm is derived and tested, and the retrieval results are validated on a meaningful data set of HR TerraSAR-X images relevant to the Gloucestershire (U.K.) flooding that occurred in year 2007.

  • Bird R, Whittaker P, Stern B, Angli N, Cohen M, Guida R. (2013) 'NovaSAR-S: A Low Cost Approach to SAR Applications'. APSAR 2013 Conference proceedings,
    [ Status: Accepted ]
  • Brett PTB, Guida R. (2013) 'Earthquake Damage Detection in Urban Areas using Curvilinear Features'. IEEE IEEE Transactions on Geoscience and Remote Sensing,
    [ Status: Accepted ]

    Abstract

    Bright curvilinear features arising from the geometry of man-made structures are characteristic of synthetic aperture radar (SAR) images of urban areas, particularly due to double-reflection mechanisms. An approach to urban earthquake damage detection using double-reflection line amplitude change in single-look images has been established in previous literature. Based on this method, this paper introduces an automated tool for fast, unsupervised damage detection in urban areas. Ridge-based curvilinear features are extracted from a preevent SAR image, and double-reflection candidates are selected using prior probability distributions derived from a simple geometrical building model. The candidate features are then used with the ratio of a pair of single preevent and postevent SAR single-look amplitude images to estimate damage levels. The algorithm is very efficient, with overall computational complexity of $O(Nlog k)$ for an $N$-pixel image containing features of mean length $k$. The technique is demonstrated using COSMO-SkyMed data covering L'Aquila, Italy, and Port-au-Prince, Haiti.

  • Khan SS, Guida R. (2012) 'On Single-look Multivariate G Distribution for PolSAR Data'. IEEE IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 5 (4), pp. 1149-1163.
  • Guida R, Iodice A, Riccio D. (2010) 'Assessment of TerraSAR-X Products with a New Feature Extraction Application: Monitoring of Cylindrical Tanks'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE T GEOSCI REMOTE, 48 (2), pp. 930-938.
  • Guida R, Iodice A, Riccio D. (2010) 'Height Retrieval of Isolated Buildings From Single High-Resolution SAR Images'. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 48 (7), pp. 2967-2979.
  • Guida R, Iodice A, Riccio D, Stilla U. (2008) 'Model-Based Interpretation of High-Resolution SAR Images of Buildings'. IEEE IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 1 (2), pp. 107-119.

    Abstract

    High-resolution (HR) synthetic aperture radar (SAR) images of urban areas reveal a large variety of details that, although potentially bringing a lot of information, are often very difficult to interpret. Until now, most of the research activity in this field has been devoted to the attempt to retrieve geometric information on buildings in terms of their positions and sizes, by using simplified geometrical models. However, this approach does not allow us to fully exploit the large amount of information present in HR SAR images. In order to improve information retrieval from such images, and, hence, their interpretation, in this paper, we propose to employ a more refined model that accounts for both geometrical (including fine details) and electromagnetic properties of the building. A meaningful case study is presented to show that the main features appearing on the SAR image of a building can be interpreted by using our geometric and electromagnetic model. In addition, a first example of retrieval of the complex dielectric constant of building materials from a SAR image is presented.

  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G. (2007) 'Building Height Retrieval From Radiometric Parameters On SAR Images'. Italian Society of Remote Sensing (Associazione Italiana di Telerilevamento - AIT) Rivista Italiana di Telerilevamento - Italian Journal of Remote Sensing, 38, pp. 97-106.
  • Guida R, Franceschetti G, Iodice A, Riccio D. (2006) 'A Tool for Planning of High Resolution/Wide Coverage Imaging Radars'. Italian Society of Remote Sensing (Associazione Italiana di Telerilevamento - AIT) Rivista Italiana di Telerilevamento - Italian Journal of Remote Sensing, 35, pp. 45-52.
  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G. (2004) 'Efficient Simulation of hybrid stripmap/spotlight SAR raw signals from extended scenes'. IEEE IEEE Transactions on Geoscience and Remote Sensing, 42 (11), pp. 2385-2396.

    Abstract

    The hybrid stripmap/spotlight mode for a synthetic aperture radar (SAR) system is able to generate microwave images with an azimuth resolution better than the one achieved in the stripmap mode and a ground coverage better than the one of the spotlight mode. In this paper, time- and frequency-domain-based procedures to simulate the raw signal in the hybrid stripmap/spotlight mode are presented and compared. We show that a two-dimensional Fourier domain approach, although highly desirable for its efficiency, is not viable. Accordingly, we propose a one-dimensional (1-D) range Fourier domain approach, followed by 1-D azimuth time-domain integration. This method is much more efficient than the time-domain one, so that extended scenes can be considered. In addition, it involves approximations usually acceptable in actual cases. Effectiveness of the simulation scheme is assessed by using numerical examples.

Conference papers

  • Khan S, Doulgeris AP, Savastano S, Guida R. 'Automatic clustering of multispectral data using a non-Gaussian statistical model'. International Geoscience and Remote Sensing Symposium (IGARSS), , pp. 4276-4279.
  • Iervolino P, Guida R, Lumsdon P, Janoth J, Clift M, Minchella A. (2017) 'Ship detection in SAR imagery: a comparison study'. IEEE Proceedings of the IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2017), Fort Worth, Texas, USA: IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2017)

    Abstract

    This paper presents a ship-detection study with Synthetic Aperture Radar (SAR) images acquired at two different frequencies: X- and C-band. The detection procedure relies on a novel algorithm based on the likelihood functions of both canonical ship target and sea clutter. Spaceborne images were acquired over the same area in the Solent Channel in UK at approximately the same time on the 7th June 2016. Here, datasets are compared in terms of probability of detection (PD), probability of false alarm (PFA) and Target-to-Clutter Ratio (TCR). Detection maps are validated with Automatic Identification System (AIS) data when available and preliminary results show a higher TCR for the X-band SAR image.

  • Cabrera Alvarado S, Guida R, Iervolino P . (2016) 'The Use of Earth Observation to Address SDG13 Climate Change in Mexico The UK and Mexico Cooperation to Address Environmental Protection: The Bacalar Case Study'. Guadalajara, Mexico: 67th IAC 2016
    [ Status: Accepted ]

    Abstract

    One of the main goals of the State is to guarantee the security and welfare of the citizens. States have agreed in making “a better world” for citizens under the United Nations (UN) Sustainable Development Goals (SDG) targets and actions. States have acquired the obligation to address this mandate and seek all possible solutions to address it. International cooperation and the use of space technology are tools to achieve this endeavor. This paper discusses the innovations of international cooperation introduced by States and its impact in law-making agreements focusing on Climate Change effects and the protection of the environment under the SDG 13. It explains the innovation in cooperation and law-making procedures by taking as an example the UK-Mexico cooperation for the protection of the Bacalar region and its ecosystem within the International Partnership Space Programme (IPSP). Within this scenario, an Earth observation (EO) product for the flood detection using Synthetic Aperture Radar (SAR) images is presented and efficiently tested over two images acquired during the Hurricane Dean in 2007. Disclaimer: The information and contents in this paper are solely the original work of the author and does not claim to represent the views of the UKSA, AEM and/or its space partners.

  • Guida R, Iervolino P, Freemantle T, Spittle S, Minchella A, Marti P, Napiorkowska M, Howard G, Arana HH, Alvarado SC. (2016) 'Earth Observation for the Preservation of the Bacalar Area'. Spacebooks Online Living Planet Symposium 2016, Prague, Czech Republic: 5th ESA Living Planet Symposium (LPS16)
  • Guida R, Ng SW. (2015) 'S- and X-band SAR data fusion'. IEEE / Curran Associates Inc. Proceedings of 2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR), Marina Bay Sands, Singapore: APSAR 2015 (2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar), pp. 578-581.

    Abstract

    This paper investigates the benefits deriving from introducing a wavelet-transform-based fusion framework for multi-frequency Synthetic Aperture Radar (SAR) data. A specific application is considered in the assessment of the fused classification map derived and this is the discrimination of different kinds of oil in sea. S-band and X-band datasets, concurrently acquired from the same airborne platform, have here been used. The findings suggest that fusing S-band and X-band SAR data does improve the oil type discrimination between crude oil and diesel oil used in the exercise, although a more quantitative analysis should be conducted in the future to measure the degree of improvement.

  • Iervolino P, Guida R, Whittaker P. (2015) 'A Novel Ship-Detection Technique for Sentinel-1 SAR Data'. IEEE / Curran Associates Inc. Proceedings of 2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR), Marina Bay Sands, Singapore: APSAR 2015 (2015 IEEE 5th Asia-Pacific Conference on Synthetic Aperture Radar), pp. 797-801.

    Abstract

    The paper shows a novel algorithm for ship-detection in Synthetic Aperture Radar (SAR) imagery. The algorithm is divided in three main steps: land mask rejection, detection and discrimination. In the first step land pixels are rejected by using Shuttle Radar Topography Mission (SRTM) data; in the second stage the potential ships are detected on a method based on the Generalized Likelihood Ratio Test (GLRT) and, finally, some targets are rejected by removing the azimuth ambiguities and by gathering the target pixels in clusters. The algorithm is tested on a Sentinel-1 image acquired over the Portsmouth harbour and compared with the outcomes coming from a Constant False Alarm Algorithm (CFAR).

  • Guida R. (2015) 'Multi-Sensor Data Fusion for Long Range Demining Area Reduction'. Milan, Italy: IGARSS 2015
    [ Status: Accepted ]
  • Iervolino P, Guida R, Whittaker P. (2015) 'A New GLRT-Based Ship Detection Technique in SAR Images'. Milan, Italy: IGARSS 2015
  • Guida R, Fotias V. (2015) 'Soil Moisture Retrieval with S-Band SAR Data'. Milan, Italy: IGARSS 2015
  • Guida R, Marcello J, Eugenio F. (2015) 'SAR, Optical and Lidar Data Fusion for the High Resolution Mapping of Natural Protected Areas'. IGARSS 2015
    [ Status: Accepted ]
  • Guida R, Brett PTB. (2014) 'Remote sensing and crowd-sourcing for water-quality measurements in Malawi'.
    [ Status: Accepted ]
  • Hagen-Zanker AH, guida . (2014) 'A computational framework for scale-sensitive landscape pattern analysis'. Glasgow: GISRUK
  • Bird R, Whittaker P, Stern B, Angli N, Cohen M, Guida R . (2014) 'NovaSAR-S: A Low Cost Approach to SAR Applications'. IEEE Conference Proceedings of 2013 Asia-Pacific Conference on Synthetic Aperture Radar (APSAR), Tsukuba, Japan: APSAR 2013 The 4th Asia-Pacific Conference on Synthetic Aperture Radar

    Abstract

    NovaSAR-S is SSTL’s revolutionary small Synthetic Aperture Radar (SAR) satellite designed for low cost missions. The instrument specification and mission characteristics of the NovaSAR satellite have been designed to provide benefit to a range of applications - the key ones being maritime surveillance (including ship and oil slick detection), forestry, disaster monitoring (particularly flooding) and agriculture. The paper will present an assessment of the ability of NovaSAR to address these key applications and provide examples of products that could be derived from NovaSAR imagery to support these applications.

  • Iervolino P, Guida R, Whittaker P. (2014) 'ROUGHNESS PARAMETERS ESTIMATION OF SEA SURFACE FROM SAR IMAGES'. IEEE Geoscience and Remote Sensing Symposium (IGARSS), 2014 IEEE International, Quebec City: IGARSS, pp. 5013-5016.

    Abstract

    Some knowledge of sea state and conditions is input in ship detection algorithms based on inversion of scatteri ng models for Synthetic Aperture Radar (SAR) images. This paper shows a novel technique for the estimati on of roughness parameters of the sea surface from SAR images. The estimation procedure is based on the minimization of the absolute error between the Radar Cross Section (RCS) of the sea surface measured on the SAR image and the expected RCS computed using the Kirchhoff approach within the Geometrical Optics (GO) solution. The technique is tested on three different TerraSAR-X images acquired in November 2012 over the Portsmouth harbour in the UK

  • Iervolino P, Cohen M, Guida R, Whittaker P. (2014) 'Ship-detection in SAR imagery using Low Pulse Repetition Frequency Radar'. VDE EUSAR 2014, EUSAR

    Abstract

    The paper introduces a novel approach for ship-detection and ambiguity removal in images acquired from Synthetic Aperture Radar (SAR) operating in Low Pulse Repetition Frequency (LPRF) mode. The procedure consists of four steps. In the detection step, the bright clusters of pixels representative of the ships are isolated using a Constant False Alarm Rate (CFAR) algorithm; in the maximum selection step a pixel maximum in amplitude is chosen for each cluster; in the third step the isolated pixels are interpolated and, finally, the stationary point of the curve, corresponding to the actual position of the target, is computed. The algorithm is tested on an airborne S-band SAR image of the Solent in the United Kingdom.

  • Bird R, Whittaker P, Stern B, Angli N, Cohen M, Guida R. (2013) 'NovaSAR-S: A Low Cost Approach to SAR Applications'. Tsukuba, Japan: APSAR
  • Iervolino P, Guida R, Whittaker P. (2013) 'NovaSAR-S and Maritime Surveillance'. IGARSS Proceedings, Melbourne, Australia: IEEE Geoscience and Remote Sensing Symposium

    Abstract

    The paper shows a new algorithm for ship-detection from Synthetic Aperture Radar (SAR) images. The algorithm consists of three main stages: pre-processing, detection and discrimination. In the pre-processing a land mask is obtained considering the different statistics between the sea and the land’s backscattered field; the detection stage isolates the bright points over the sea background employing a Constant False Alarm (CFAR) method; while the ships are retrieved, in the discrimination step, by evaluating the scattering contributions of the possible targets detected in the previous stage. The algorithm is tested on an airborne S-band SAR image of Portsmouth harbor, similar to those that will become available with the upcoming UK SAR mission NovaSAR-S.

  • Khan S, Guida R . (2013) 'Single-Look PolSAR Statistical Analysis Using Fractional Moments of Polarimetric Whitening Filter'. Melbourne, Australia: International Geoscience and Remote Sensing Symposium. IGARSS 2013

    Abstract

    This paper proposes a new method of estimating the shape parameters of polarimetric singlelook complex compound distributions which model synthetic aperture radar data. The estimators derived from this method utilize fractional moments of polarimetric whitening filter, and can be derived for all commonly occurring distributions. They also exhibit low variance properties.

  • Guida R, Brett PTB, Khan SS. (2013) 'Remote Sensing and Crowd-Sourcing'. IEEE IGARSS Proceedings, Melbourne, Australia: IEEE Geoscience and Remote Sensing Symposium
    [ Status: Accepted ]

    Abstract

    Collection of ground truth to validate remote sensing classification and/or detection algorithms is rarely accounted for due to the inaccessibility of the sites or the elevated costs of such operations. In this paper some of the opportunities behind crowd sourcing are explored through the description of a remote sensing project on water quality monitoring in Africa where the ground truth was collected involving and training people from local communities.

  • Khan, SS, Guida R. (2012) 'THE NEW DUAL-TEXTURE G DISTRIBUTION FOR SINGLE-LOOK POLSAR DATA'. IEEE IGARSS 2012, pp. 1469-1472.

    Abstract

    A new form of G distribution, called the dual-texture G distribution, is proposed for Single-Look Complex (SLC) PolSAR data. Unlike the scalar texture productmodel, the dual texture G distribution is derived considering different texture variables for co-pol and cross-pol (x-pol) channels. The co-pol and x-pol texture variables are modelled by the Generalized Inverse Gaussian (GIG) distribution, separately. The result is a more flexible multivariate distribution. Also Mellin Kind Statistics (MKS) are utilized to analyze GIG textures, observe evidence of dual texture and to estimate shape parameters.

  • Guida R, Natale, A, Bird, R, Whittaker, P, Cohen, M, Hall, D . (2012) 'CANOPY CLASSIFICATION WITH S-BAND POLARIMETRIC SAR DATA'. IEEE IEEE International Geoscience and Remote Sensing Symposium IGARSS 2012, pp. 6535-6538.

    Abstract

    New Synthetic Aperture Radar (SAR) missions in S-band are currently under design but the potential performance of this microwave frequency is still under discussion. This paper presents the outcomes of a study on canopy classification carried out with fully polarimetric S- and X-band datasets contemporaneously acquired by the Astrium airborne SAR demonstrator. Classical polarimetric decompositions have been applied to investigate the S-band capabilities in vegetation monitoring and preliminary results are here presented.

  • Iervolino P, Guida R, Iodice A, Riccio D. (2012) 'FLOODING LEVEL ESTIMATION IN URBAN AREAS WITH SAR IMAGES'. GOLD Conference
  • Natale, A, Guida R, Bird, R, Whittaker, P, Hall, D, Cohen, M . (2012) 'Validation of S-band data performance for future spaceborne SAR missions'. IEEE EUSAR. 9th European Conference on Synthetic Aperture Radar, Nuremberg, Germany: EUSAR 2012, pp. 75-78.

    Abstract

    Most of the SAR missions of the latest years presented sensors working in X-band (like in the TerraSAR-X and Cosmo-SkyMed missions). Today new SAR missions, working at alternative frequencies like S-band, are under planning/design and will be launched in the upcoming years. In addition, full polarimetry is likely to be implemented in some of those missions. This is the case of the UK sensor NovaSAR-S to be launched by 2013. In order to validate the performance of S-band, especially in comparison with the better known and tested X-band, an airborne demonstrator has been set up to contemporaneously acquire fully polarimetric SAR data in both bands. In this paper we present, compare and discuss results deriving from the application of the H/α and the Pauli decompositions to the fully polarimetric datasets in both bands to understand possible advantages of S-band in specific applications.

  • Khan SS, Guida R. (2012) 'The new form of G distribution for single-look PolSAR data'. IEEE EUSAR. 9th European Conference Synthetic Aperture Radar, Nuremberg, Germany: EUSAR 2012, pp. 523-526.
  • Brett, P.T.B., Guida R. (2012) 'Geometry-based SAR curvilinear feature selection for damage detection'. IEEE EUSAR. 9th European Conference on Synthetic Aperture Radar, Nuremberg, Germany: EUSAR 2012, pp. 62-65.

    Abstract

    Bright curvilinear features in Synthetic Aperture Radar (SAR) images arising from the geometry of urban structures have been successfully used for estimating urban earthquake damage, using single pre- and post-event high resolution amplitude SAR images. In this paper, further automation of the process of selecting candidate curvilinear features for change detection is proposed, based on a model selection using priors derived from idealised building geometry. The technique is demonstrated using COSMO-SkyMed data covering the 2010 Port-au-Prince earthquake.

  • Natale A, Guida R, Bird R, Whittaker P, Cohen M, Hall D. (2011) 'Demonstration and analysis of the applications of S-band SAR'. 2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, Seoul, South Korea: 3rd APSAR 2011, pp. 167-170.

    Abstract

    The use of some working frequencies is still novel in Synthetic Aperture Radar (SAR) especially when associated to a full exploitation of polarimetric channels. In this paper the potential value of a spaceborne multi-pol SAR system in S-band (3.2 GHz) is presented following the first acquisitions of the Astrium UK airborne SAR demonstrator and relevant analysis based on Pauli and eigenvalue-eigenvector decompositions. Most interesting results are presented and discussed.

  • Guida R, Iodice A, Riccio D. (2011) 'An application of the deterministic feature extraction approach to COSMO-SKyMed data'. Proceedings of the European Conference on Synthetic Aperture Radar, Aachen (germany): EUSAR10, pp. 1014-1017.

    Abstract

    In the last years a new feature extraction approach from a single amplitude SAR image of urban areas has been introduced by the authors. In this paper they discuss the feasibility of this approach to detect changes in urban areas when natural hazards occur, with the aim to identify damaged or collapsed buildings by monitoring changes in the radiometric content of relevant SAR images. The test is performed on COSMO-SKyMed data provided before and after the earthquake that took place in the area around L¿Aquila, Italy, in April 2009. First results are presented and discussed.

  • Guida R, Brett PTB. (2011) 'A SAR image-based tool for prompt and effective earthquake response'. IEEE Proceedings of 2011 Joint Urban Remote Sensing Event, Munich, Germany: JURSE 2011, pp. 213-216.

    Abstract

    Recently, a new concept for detection of damaged infrastructure after earthquakes has been introduced, based on analysis of double reflection lines in SAR images. This paper describes the development of a processing step for extraction of double-reflection lines, and its implementation. In particular, an unsupervised bright line detector working on the ratio of pre- and post-event single look complex SAR data is introduced, and is demonstrated using COSMO-SkyMed SAR data from the 2009 L'Aquila earthquake.

  • Iervolino P, Diessa V, Iodice A, Ricciardi A, Riccio D, Guida R. (2011) 'A new local approach for flooding level estimation in urban areas using single SAR images'. IEEE Proceedings of 2011 Joint Urban Remote Sensing Event, Munich, Germany: JURSE 2011, pp. 257-260.

    Abstract

    The aim of this paper is to evaluate the level of flooding in proximity of sensible targets in urban areas using only one Synthetic Aperture Radar (SAR) image. To this purpose a two-step algorithm is here proposed: first the flooded areas are detected in the SAR image; and then the water level is retrieved by inverting scattering models developed for urban areas and now properly adapted for the case at issue. The retrieval is performed through a local approach where the a-priori knowledge of the target ground truth and two gauges in the premises is required. The approach is tested on a High Resolution (HR) TerraSAR-X image acquired during the flooding occurred in the Gloucestershire in July 2007.

  • Brett PTB, Guida R. (2011) 'Bright line detection in COSMO-SkyMed SAR images of urban areas'. IEEE Proceeedings of Joint Urban Remote Sensing Event, Munich, Germany: JURSE 2011, pp. 253-256.

    Abstract

    Bright lines are a characteristic feature of synthetic aperture radar (SAR) amplitude images of urban areas, and are commonly associated with man-made structures. In order to aid in the development of SAR applications using these features, an automated approach to bright line detection is proposed, based on scale-space ridge detection at a single scale, and using a naïve Bayesian classification step to select the ridge points corresponding to bright lines. The effectiveness of the technique is demonstrated by applying it to a COSMO-SkyMed image of L'Aquila, Italy.

  • Khan S, Guida R. (2011) 'Feasibility of time-frequency urban area analysis on TerraSAR-X fully polarimetric dataset'. IEEE Proceedings of 2011 Joint Urban Remote Sensing Event, Munich, Germany: JURSE 2011, pp. 265-268.

    Abstract

    The feasibility of azimuthal Time-Frequency (TF) analysis for urban area identification using TerraSAR-X (TX) fully polarimetric data has been investigated for the first time. Space-borne sensors, unlike airborne sensors, are characterized by a very small azimuth antenna aperture, which limits the Sub-Aperture (SA) decomposition in the azimuth direction. Due to this limitation, the usefulness of SA decomposition for space-borne sensors, has still not been explored. Pixel stationarity, which generally has lower values over urban areas, has been measured for TX data. It has been found that the full doppler spectrum has to be utilized for TX to generate a meaningful stationarity pixel map from SA coherency matrices. This analysis has been performed on TX fully polarimetric data acquired in April, 2009 over a site called Wallerfing in Germany.

  • Guida R, Iodice A, Riccio D. (2010) 'MONITORING OF COLLAPSED BUILT-UP AREAS WITH HIGH RESOLUTION SAR IMAGES'. IEEE 2010 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, Honolulu, HI: IEEE International Geoscience and Remote Sensing Symposium, pp. 2422-2425.
  • Guida R. (2010) 'Introduction of Podcasts in Remote Sensing Education'. IEEE Proceedings of the IEEE International Geoscience and Remote Sensing Symposium, Honolulu, USA: IGARSS'10, pp. 1104-1106.

    Abstract

    This paper deals with a new teaching experience carried on at the Department of Electronic Engineering at University of Surrey. The experience is based on the enhancement of students learning in the Satellite Remote Sensing class with the adoption of new technologies for assessment and teaching purposes. More precisely, podcasts have been introduced in a 3-year long project as supporting teaching material or coursework. Here the experience of the first year, where podcasts are introduced as group coursework, is described in detailed and commented.

  • Guida R, Iodice, A, Riccio, D . (2010) 'Fast Change Detection Algorithm for Single Post-Earthquake SAR Images of Urban Areas'. SIEm Proceedings of the 18th RiNEm, Beneveneto, Italy: RiNEm
  • Guida R, Franceschetti G, Iodice A, Riccio D. (2009) 'Electromagnetic Modelling for Information Extraction from High Resolution SAR Images of Urban Areas'. IEEE Proceedings of the IEEE International Geoscience and Remote Sensing Symposium '08, Boston (Massachusetts, USA): IGARSS'08 1, pp. I-78-I-81.

    Abstract

    Analysis, interpretation and feature extraction concerning High Resolution (HR) Synthetic Aperture Radar (SAR) images of urban areas urgently require support of sound and appropriate electromagnetic modelling. The modelling takes into consideration the radar geometry and the (geometric and electromagnetic) scene parameters but also the novelty brought by high resolution. In this paper, this way of developing suitable electromagnetic modelling for HR SAR images of urban areas is shown to be successful as able to interpret and retrieve, from these scenarios, new and interesting details that will certainly represent the main actor of next generation of applications for urban areas with SAR sensors.

  • Guida R, Iodice A, Riccio D. (2009) 'SAR monitoring of suburban areas based on an electromagnetic scattering model'. IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Cape Town: International Geoscience and Remote Sensing Symposium (IGARSS) 5, pp. V104-V107.

    Abstract

    Cylindrical-shape tanks are typical of any suburban area and often contain dangerous gases or fluids. In this paper, we suggest a way to monitor them by means of high resolution Synthetic Aperture Radar (SAR) images and a scattering model able to quantitatively consider how the radar signal interacts with this kind of structures and how they appear m the SAR images. Adopting the model, geometrical information as the tank height is retrieved from the SAR images m a non-conventional way that is exploiting the information content contained m the double reflection contribution to the radar cross section. Results are compared with more traditional methods and discussed.

  • Guida R, Franceschetti G, Iodice A, Riccio D. (2008) 'TerraSAR-X for urban areas monitoring: novelties and promises of High Resolution'. Oberpfaffenhofen, Munich (Germany): TerraSAR-X Science Team Meeting
  • Franceschetti G, Guida R, Iodice A, Riccio D. (2008) 'Modelli elettromagnetici per immagini SAR ad alta risoluzione di edifici'.
  • Guida R, Iodice A, Riccio D. (2008) 'New Models for the Analysis of High Resolution SAR Images of Urban Areas'. Proceedings of the IEEE GOLD Conference, Frascati (Italy): IEEE GOLD Conference
  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G, Stilla U. (2008) 'Building Feature Extraction via a Deterministic Approach: Application to Real High Resolution SAR Images'. IEEE IEEE International Geoscience and Remote Sensing Symposium, Barcelona (Spain): IGARSS'07, pp. 2681-2684.

    Abstract

    Interpretation of high resolution SAR (synthetic aperture radar) images is still a hard task, especially when man-made objects crowd the scene under detection. This paper contributes to the analysis of this kind of data by adopting an approach, based on a scattering model, for the retrieval of buildings height from real SAR images and presenting first numerical results.

  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G. (2007) 'Accuracy of Building Height Estimation from SAR images'. IEEE Proceedings of the IEEE International Geoscience and Remote Sensing Symposium '06, Denver (Colorado,USA): IGARSS'06, pp. 3647-3650.

    Abstract

    Abstract—Applicability and efficiency of building height retrieval from radiometric parameters on SAR images is here investigated. The influence of an imperfect knowledge of ground truth is studied by means of a theoretical analysis compared with results deriving from simulation examples. For some cases, propagated errors are quantitatively evaluated and discussed.

  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G, Stilla U. (2007) 'Simulation Tools for Interpretation of High Resolution SAR Images of Urban Areas'. IEEE Urban Remote Sensing Joint Event, 2007, Paris (France): 4rd RSS/ISPRS joint Symposium on Remote Sensing and Data Fusion over Urban Areas

    Abstract

    New powerful spaceborne sensors for monitoring urban areas have been designed and are ready for launch. More detailed SAR images will be soon available and, consequently, new tools for their interpretation are needed, above all when urban scenes are illuminated. In this paper, the authors propose some tools for the study and the analysis of high resolution SAR images based on a SAR raw signal simulator for urban areas. Comparing simulated SAR images with the real one, interpretation of SAR data is improved and fundamental support of the employed tools is further assessed.

  • Franceschetti, G, Guida R, Iodice, A, Riccio, D, Ruello, G, Stilla, U . (2007) 'ELECTROMAGNETIC FEATURE EXTRACTION FROM REAL SAR IMAGES OF BUILT-UP AREAS'. Proceedings of the 27th Symposium of the European Association of Remote Sensing Laboratories (EARSeL), Bolzano, Italy: 27th EARSeL Symposium: Geoinformation in Europe
  • Franceschetti, G, Guida R, Iodice, A, Riccio, D, Ruello, G . (2006) 'ANALISI DI SENSIBILITA’ PER LA STIMA DELL’ALTEZZA DI EDIFICI DA IMMAGINI SAR'. Genova, Italy: XVI RiNEm

    Abstract

    In the last years, new approaches for feature extraction from high resolution SAR images have been presented. One of them is the deterministic approach for building height retrieval from double reflection contribution on SAR images of urban areas. Actually, promising results can be guaranteed only if a high aprioristic knowledge of involved radar and scene parameters is available, but this requirement is not always satisfied. For this reason, here we investigate the influence of an imperfect knowledge of the scene on the final result of building height estimation. In particular, by means of sensitivity analyses and simulation examples, the influence on the height retrieval of an error on the knowledge of the angle between the building wall and the radar flight trajectory is investigated and discussed.

  • Franceschetti, G, Guida R, Iodice, A, Riccio, D, Ruello, G . (2006) 'VERIFICA DI UN SOFTWARE PER LA PREVISIONE DELLA RADIOCOPERTURA'. Genova, Italy: XVI RiNEm

    Abstract

    In this paper a measurement procedure for the validation of a software for the evaluation of the electromagnetic field levels in urban environment is presented. The considered software is a ray-tracing based tool. It relies on a deterministic description of the macroscopic environment and a statistical contribution to account for the several random phenomena typical of urban scenarios. The measurements are performed in an area made of different building density and properties. A transmitting antenna radiated a field, whose values were acquired by a receiver mounted on a car. The obtained measured data are compared with the software evaluation. Matching and differences between measurements and theoretical results are provided.

  • Franceschetti G, Guida R, Iodice A, Riccio D, Ruello G. (2005) 'Building Height Retrieval From Radiometric Parameters On SAR Images'. Mantova, Italy: AIT/SIFET Workshop

    Abstract

    Urban structure detection, in terms of both geometric and electromagnetic features, from a single Synthetic Aperture Radar (SAR) image is, nowadays, an interesting still open challenge. Within this framework a new deterministic approach for the extraction of the height of an isolated building on a rough terrain is presented. The approach is based on a sound electromagnetic model which fully represents the electromagnetic return from an isolated building to an active microwave sensor, analytically evaluated in closed form. Particularly, building height is extracted from double scattering contribution to the radar cross section measured on the SAR image. Some simulation examples, relative to canonical scenes, accompany and validate the approach proposed.

  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G. (2005) 'Models for Features Extraction from SAR images of Urban Areas'. Proceedings of the XXVIIIth URSI General Assembly, New Delhi (India): URSI 2005
  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G. (2005) 'Deterministic Extraction of Building Parameters from High Resolution SAR Images'. Proceedings of the 3rd RSS/ISPRS joint Symposium on Remote Sensing and Data Fusion over Urban Areas, Tempe (Arizona,USA): Symposium on Remote Sensing and Data Fusion over Urban Areas
  • Guida R, Franceschetti G, Iodice A, Riccio D, Ruello G. (2004) 'Efficient Hybrid Stripmap/Spotlight SAR Raw Signal Simulation'. IEEE Proceedings of the IEEE International Geoscience and Remote Sensing Symposium '04, Anchorage (Alaska, USA): IGARSS'04 3, pp. 1767-1769.

    Abstract

    Recently, a new operating mode for Synthetic Aperture Radar (SAR) system, referred to as hybrid stripmap/spotlight mode, has been presented [1-2]. In the hybrid acquisition mode the radar antenna beam is steered about a point farther away from the radar than the area being illuminated, thus generating microwave images with an azimuth resolution better than that achieved in the stripmap configuration, and a ground coverage better than the one of the spotlight configuration. The subject of design, processing and data interpretation for the hybrid SAR mode is gaining an increasing interest in the remote sensing scientific community. Consequently, a hybrid SAR raw signal simulator is strongly required, especially when real raw data are not available yet, to test processing algorithms and to help mission planning. In addition, to analyse the effects of processing errors and to verify the impact of different system design choices on the final image for different kinds of imaged scenes, an extended scene SAR raw signal simulator simulator is very useful: it is what we present in this paper. After showing that in this case a 2D Fourier domain approach is not viable, we demonstrate that a 1D range Fourier domain approach, followed by 1D azimuth time domain integration, is possible when some approximations, usually valid in the actual cases, are accepted.

  • Guida R, Iodice A, Riccio D. (2004) 'A New Efficient Simulator for Hybrid SAR Raw Signals'. IEEE Napoli (Italy): IEEE GOLD Remote Sensing Conference Conference

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