Research

Earth observation and climate

Hypergraphs over NASA Earth-observation layers that predict one climate variable from the others.

1 paper

We use the same hypergraph models as for drone video, applied to dozens of NASA Earth Observations (NEO) layers: aerosol optical depth, chlorophyll, cloud fraction, vegetation index, temperature and others. Each layer is predicted from the rest (ICCV 2023 Workshops). The monthly version of the dataset is on Hugging Face. Alexandru Todoran works on climatic correlations between these layers and on semi-supervised learning with ensembles of randomly masked autoencoders.

Datasets

NEO: NASA Earth Observations, monthly

On Hugging Face

Monthly global NASA Earth Observations layers at 540×1080, prepared for multi-task learning, with loaders, viewer notebooks and train/test splits.

AOD, Chlorophyll, Cloud fraction, NDVI, Temperature, + more

Publications (1)

Multi-Task Hypergraphs for Semi-supervised Learning using Earth Observations

Mihai Pirvu, Alina Marcu, Alexandra Dobrescu, Nabil Belbachir, Marius Leordeanu

Proceedings of the IEEE/CVF International Conference on Computer Vision Workshops (ICCVW), 2023

Abstract

There are many ways of interpreting the world and they are highly interdependent. We exploit such complex dependencies and introduce a powerful multi-task hypergraph, in which every node is a task and different paths through the hypergraph reaching a given task become unsupervised teachers, by forming ensembles that learn to generate reliable pseudolabels for that task. Each hyperedge is part of an ensemble teacher for a given task and it is also a student of the self-supervised hypergraph system. We apply our model to one of the most important problems of our times, that of Earth Observation, which is highly multi-task and it often suffers from missing ground-truth data. By performing extensive experiments on the NASA NEO Dataset, spanning a period of 22 years, we demonstrate the value of our multi-task semi-supervised approach, by consistent improvements over strong baselines and recent work. We also show that the hypergraph can adapt unsupervised to gradual data distribution shifts and reliably recover, through its multi-task self-supervision process, the missing data for several observational layers for up to seven years.