Agnieszka Chojka

Dr. Agnieszka Chojka

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
21 May 2020 in Sensors
Verified
Journal Article
Open access
PDF file
ACAgnieszka Chojka
Agnieszka Chojka
Piotr ArtiemjewPiotr Artiemjew
Piotr Artiemjew
JRJacek Rapinski
Jacek Rapinski
Interferometric Synthetic Aperture Radar (InSAR) data are often contaminated by Radio-Frequency Interference (RFI) artefacts that make processing them more challenging. Therefore, easy to implement techniques for artefacts recognition have the potential to support the automatic Permanent Scatterers InSAR (PSInSAR) processing workflow during which faulty input data can lead to misinterpretation of the final outcomes. To address this issue, an efficient methodology was developed to mark images with RFI artefacts and as a consequence remove them from the stack of Synthetic Aperture Radar (SAR) images required in the PSInSAR processing workflow to calculate the ground displacements. Techniques presented in this paper for the purpose of RFI detection are based on image processing methods with the use of feature extraction involving pixel convolution, thresholding and nearest neighbor structure filtering. As the reference classifier, a convolutional neural network was used.

22 December 2020 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Piotr ArtiemjewPiotr Artiemjew
Piotr Artiemjew
ACAgnieszka Chojka
Agnieszka Chojka
JRJacek Rapinski
Jacek Rapinski
Beyond the variety of unwanted disruptions that appear quite frequently in synthetic aperture radar (SAR) measurements, radio-frequency interference (RFI) is one of the most challenging issues due to its various forms and sources. Unfortunately, over the years, this problem has grown worse. RFI artifacts not only hinder processing of SAR data, but also play a significant role when it comes to the quality, reliability, and accuracy of the final outcomes. To address this issue, a robust, effective, and—importantly—easy-to-implement method for identifying RFI-affected images was developed. The main aim of the proposed solution is the support of the automatic permanent scatters in SAR (PSInSAR) processing workflow through the exclusion of contaminated SAR data that could lead to misinterpretation of the calculation results. The approach presented in this paper for the purpose of recognition of these specific artifacts is based on deep learning. Considering different levels of image damage, we used three variants of a LeNet-type convolutional neural network. The results show the high efficiency of our model used directly on sample data.

25 April 2020 in Applied Sciences
Verified
Journal Article
Open access
PDF file
Kamil KowalczykKamil Kowalczyk
Kamil Kowalczyk
AKAnna Maria Kowalczyk
Anna Maria Kowalczyk
ACAgnieszka Chojka
Agnieszka Chojka
The main aim of this study was to evaluate the applicability of the co-kriging method for modeling the vertical movements of the Earth’s crust based on data acquired with the use of precision leveling techniques and measurements conducted by permanent Global Navigation Satellite System (GNSS) stations. Data were processed with the use of empirical, theoretical, and directional variograms (semivariograms), as well as variogram maps. Large-scale spatial variability was determined using polynomial regression. The relationships between the length of the semi-major and semi-minor axes vs. the root mean square (RMS) and the standard error of the estimate were analyzed. The relationships between the anisotropic direction and the number of lags were determined, and other parameters were calculated. Preliminary data fitting produced non-stationary surfaces. The leveling data were anisotropic, and the GNSS data were isotropic. Nugget effects were observed in both datasets, in particular in the GNSS data. The size of the ellipse was strongly correlated with the RMS and σ (average standard deviation of prediction). The anisotropy angle was determined using the number of lags. Co-kriging was found to not be a suitable method for modeling the vertical movements of the Earth’s crust based on data from various sources. The final result was strongly influenced by the initial dataset. The obtained results show how the method of combining data sets (interpolation, network adjustment) affected the final cartographic model.

13 August 2025 in Computers
Verified
Journal Article
Open access
PDF file
Telmo AdãoTelmo Adão
Telmo Adão
ACAgnieszka Chojka
Agnieszka Chojka
DPDavid Pascoal
David Pascoal
NSNuno Miguel dos Santos Pinto da Silva
Nuno Miguel dos Santos Pinto da Silva
Raul MoraisRaul Morais
Raul Morais
Emanuel PeresEmanuel Peres
Emanuel Peres
The development of reliable visual inference models is often constrained by the burdensome and time-consuming processes involved in collecting and annotating high-quality datasets. This challenge becomes more acute in domains where key phenomena are time-dependent or event-driven, narrowing the opportunity window to capture representative observations. Yet, accelerating the deployment of deep learning (DL) models is crucial to support timely, data-driven decision-making in operational settings. To tackle such an issue, this paper explores the use of 2D synthetic data grounded in real-world patterns to train initial DL models in contexts where annotated datasets are scarce or can only be acquired within restrictive time windows. Two complementary approaches to synthetic data generation are investigated: rule-based digital image processing and advanced text-to-image generative diffusion models. These methods can operate independently or be combined to enhance flexibility and coverage. A proof-of-concept is presented through a couple case studies in precision viticulture, a domain often constrained by seasonal dependencies and environmental variability. Specifically, the detection of Lobesia botrana in sticky traps and the classification of grapevine foliar symptoms associated with black rot, ESCA, and leaf blight are addressed. The results suggest that the proposed approach potentially accelerates the deployment of preliminary DL models by comprehensively automating the production of context-aware datasets roughly inspired by specific challenge-driven operational settings, thereby mitigating the need for time-consuming and labor-intensive processes, from image acquisition to annotation. Although models trained on such synthetic datasets require further refinement—for example, through active learning—the approach offers a scalable and functional solution that reduces human involvement, even in scenarios of data scarcity, and supports the effective transition of laboratory-developed AI to real-world deployment environments.

21 September 2020 in Geomatics and Environmental Engineering
Verified
Journal Article
Open access
ACAgnieszka Chojka
Agnieszka Chojka
Interoperability is one of the core concepts of Spatial Data Infrastructure due to the fact that exchange and access to spatial data is the foremost aim of any SDI. These issues are closely related to the concept of application schema that plays a significant role in interchanging spatial data and information across SDI. It is the basis of a successful data interchange between two systems as it defines the possible content and structure of data, thus it covers both semantic and syntactic interoperability. These matters also appear in a couple of questions concerning SDI including, among others, a model‑driven approach and data specifications. Spatial data exchange through SDI involves UML and GML application sche­mas that comprise semantic and syntactic interoperability respectively. How­ever, working out accurate and correct application schemas may be a challenge. Moreover, their faultiness or complexity may influence the ability to valid data interchange. The principal subject of this paper is to present the concept of interoperability in SDI, especially semantic and syntactic, as well as to discuss the role of UML and GML application schemas during the interoperable exchange of spatial data over SDI. Considerations were conducted focusing on the European SDI and the National SDI in Poland.

5 September 2025 in Algorithms
Verified
Journal Article
Open access
PDF file
DPDavid Pascoal
David Pascoal
Telmo AdãoTelmo Adão
Telmo Adão
ACAgnieszka Chojka
Agnieszka Chojka
NSNuno Miguel dos Santos Pinto da Silva
Nuno Miguel dos Santos Pinto da Silva
SRSandra Rodrigues
Sandra Rodrigues
Raul MoraisRaul Morais
Raul Morais
Proper management of water resources in agriculture is of utmost importance for sustainable productivity, especially under the current context of climate change. However, many smart agriculture systems, including for managing irrigation, involve costly, complex tools for most farmers, especially small/medium-scale producers, despite the availability of user-friendly and community-accessible tools supported by well-established providers (e.g., Google). Hence, this paper proposes an irrigation management system integrating low-cost Internet of Things (IoT) sensors with community-accessible cloud-based data management tools. Specifically, it resorts to sensors managed by an ESP32 development board to monitor several agroclimatic parameters and employs Google Sheets for data handling, visualization, and decision support, assisting operators in carrying out proper irrigation procedures. To ensure reproducibility for both digital experts but mainly non-technical professionals, a comprehensive set of guidelines is provided for the assembly and configuration of the proposed irrigation management system, aiming to promote a democratized dissemination of key technical knowledge within a do-it-yourself (DIY) paradigm. As part of this contribution, a market survey identified numerous e-commerce platforms that offer the required components at competitive prices, enabling the system to be affordably replicated. Furthermore, an irrigation management prototype was tested in a real production environment, consisting of a 2.4-hectare yellow kiwi orchard managed by an association of producers from July to September 2021. Significant resource reductions were achieved by using low-cost IoT devices for data acquisition and the capabilities of accessible online tools like Google Sheets. Specifically, for this study, irrigation periods were reduced by 62.50% without causing water deficits detrimental to the crops’ development.