His international research team focuses on new imaging technologies to contrast adverse impact of climate-change-related stressors to sustainable agriculture. Based on the evidence, that the metabolism and transport of carbon, sugar and water in crops are the fundament of the mechanism of growth, he noted that Positron Emission Tomography (PET) is the only imaging technique, which allows their non-disruptive and quantitative measurement. After strengthening a new digital signal processing approach based on the Digital PET technology, Prof. D’Ascenzo explored the frontier of PET setting the theoretical, methodological, and technological fundaments for the transition from a lab-based plant PET imaging to an in-field Agri-PET imaging. In-field measurements in fact reflect the complexity of a natural environment, which lab-based experiments can only partially reproduce.

Facing the challenge of low activity and short observation time of agricultural applications, Prof. D’Ascenzo proposed the new theory of Kinetically Consistent Data Assimilation (KCDA) signal processing for incomplete dynamic crop PET signals. Prof. D’Ascenzo invented a new predictor-corrector approach, which adapts the model to the data. The new KCDA theory allows to extract quantitative parameters describing the transport and metabolism in plants by analyzing the first few minutes of the acquired TACs and enables quantitative in-field PET measurements. Based on the KCDA theory, Prof. D’Ascenzo developed new methods for the quantitative imaging of plants and crops. In contrast with preclinical and clinical imaging, plant imaging faces the problem of positron escape in thin and soft tissues. Prof. D’Ascenzo developed new correction methodologies to allow quantitative results for the early identification of plant stress.  Finally, Prof. D’Ascenzo proposed a new high-sensitivity portable technological approach to crop PET imaging, demonstrating experimentally with a prototype system the feasibility of the in-field PET imaging in agriculture.

The compactness and portability of the system is enabled also by a compact sensor technology, the CMOS SiPM, developed by Prof. D’Ascenzo. The sensor, developed in a CMOS compatible process, reaches an unprecedented photo detection efficiency of 43% at a 420 nm spectral region and a single photon time resolution of 70 ps (FWHM). On this basis, he is one of the inventors of the MVT-SiPM, which embeds single photon spatiotemporal digital signal processing on a single chip, enabling high resolution and sensitivity digital PET technologies.

The Agri-PET technology has been recognized internationally and is adopted at the Digital Imaging Multimodal Platform node of the Eurobioimaging European Research Infrastructure in Italy, and at the PETAL international consortium on dynamic crop functional imaging.  Prof. D’Ascenzo has published more than 200 top journals and conference papers and has filled 15 patents.