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saverin0/README.md

Abhishek Singh

M.Sc. Data Science. Machine learning for Earth observation and remote sensing. Berlin, Germany.

Glacier calving front drawn by a probe on frozen C-RADIO features, Mapple glacier, Sentinel-1 VGGT-Omega predicted depth against LiDAR on an FZI-AURA driving scene, error on moving objects, all 40 frames Building change detection on LEVIR-CD from frozen DINOv3 features

From left, a SAR calving front from a frozen photo-pretrained encoder (CaFFe, Sentinel-1); VGGT-Ω depth error on a driving scene, black rings mark moving objects (FZI-AURA); new buildings found from frozen DINOv3 features (LEVIR-CD).

Projects

Columbia glacier calving front, SAR, model front against real front

sar-transfer-glaciers — Do frozen encoders pretrained on optical images transfer to SAR? Glacier calving-front delineation on the CaFFe benchmark with frozen DINOv3 (satellite and photo), C-RADIOv4-H and two SAR-pretrained encoders, only small probes and heads trained on top, a U-Net from scratch as reference. A 0.57 M-parameter decoder on frozen C-RADIO features matches the 7.8 M-parameter U-Net on front error on the test glaciers (979 ± 31 m vs 979 m). Photo-pretrained encoders beat the SAR-pretrained ones we tried, and satellite pretraining gave no clear advantage over photo pretraining.

One Sentinel-1 test chip each from glacial lakes, snow, forest types and alpine glaciers, with the labels and the frozen satellite DINOv3 output

sar-transfer-domains — Part two of the SAR study. The same frozen pipeline, nothing tuned per dataset, on four Sentinel-1 datasets (glacial lakes, snow, forest types, alpine glaciers). With a small decoder, the satellite-pretrained DINOv3 is ahead of C-RADIOv4-H on every dataset and test split (snow IoU 0.735 vs 0.602), the reverse of the glacier study. In the one like-for-like published comparison, frozen features reach a snow F1 of 0.847 against 0.897 for a U-Net trained on the same radar channels. From one lake patch, 83 % of the 100 most similar test patches are lake for the satellite DINOv3, against 37 % for C-RADIO.

Patch features of the frozen satellite DINOv3 and two distilled students as colours, one Sentinel-1 chip each from glacial lakes, snow, forest types and alpine glaciers

sar-transfer-distillation — Part four of the SAR study. Can a small model learn to read Sentinel-1 radar by copying several large frozen models at once? A C-RADIO-style ViT-B student is distilled from SigLIP2, satellite DINOv3, PE-Spatial and, as a fourth teacher, TerraFM-B reading the radar itself, then scored with frozen features on the four radar datasets of part two. The student does not reach the frozen satellite DINOv3, behind on all four by 0.030 to 0.055. The radar-reading teacher helps, snow IoU 0.659 against 0.603 without it and alpine glaciers 0.508 against 0.477, with ties on lakes and forest.

VGGT-Omega depth prediction, LiDAR ground truth and signed error on all 40 frames of an urban driving scene

vggt-omega-aura-benchmark — Failure analysis of the released VGGT-Ω 3D reconstruction checkpoint on FZI-AURA, a driving dataset published after the model and so outside its training data. Depth and pose error are broken down by weather, lighting and object motion instead of averaged. Daytime depth on the held-out test split reaches AbsRel 0.082; error concentrates on thin objects, people and moving vehicles. Python reference implementation with a C++ core for the scoring.

A drone flight over a river valley in Armenia, the drone DSM, DTM and land cover at 0.5 m, then the Copernicus DEM, ESA WorldCover, a canopy height map, Sentinel-2 and OpenStreetMap on the same map

uav-lidar-vs-satellite — Raw drone sensor logs of two MARS-LVIG flights in Armenia, a river valley and a small town, turned into DSM, DTM and land cover at 0.5 m with our own ROS 2 readers, gyro-aided poses and a ground filter written in numpy, then checked against Copernicus GLO-30, ESA WorldCover, a global canopy height map, Sentinel-2 and OpenStreetMap. GLO-30 meets the drone DSM to 0.80 m RMSE on bare ground in the valley and 0.45 m in the town, sits 0.74 m below it over buildings and metres below it over trees. WorldCover agrees on 82 % of the valley but 32 % of the town, where it calls the gardens trees and grass.

LEVIR-CD before and after images, ground truth and prediction

Change-Detection-Using-Dinov3 — Building change detection on frozen satellite-pretrained DINOv3 features, on SpaceNet-7 monthly imagery and LEVIR-CD. Decoder designs compared on identical features, feature differencing at 0.56M parameters and cross-attention at 0.83M, finished within 0.002 F1 of each other at 0.910 on LEVIR-CD, so the smaller head was the one to keep. Both beat the frozen embeddings read directly by roughly ten times on SpaceNet-7. Trained on a free Colab T4.

Eight aerial survey patches where the best detector missed caribou in clear view, found animals green, misses orange, false alarms pink

owl-caribou-overhead — Cross-herd, cross-year evaluation of four overhead animal detectors on 2,607 aerial survey patches of the Central Arctic caribou herd (Alaska, 2022), with error bars from resampled mosaics, a failure analysis and a threshold sweep. The two best models tie threshold-free (average precision 0.978 vs 0.977); the gap at the fixed setting is an operating-point effect. Half of the remaining errors sit in a 16 px band at the patch border, and most of those are real animals the patch's ground truth does not list.

Monthly winter wheat NDVI time series across Bavarian districts

bavaria-wheat-sentinel2-oco2 — Monthly NDVI and NIRv for winter wheat across the 96 NUTS-3 regions of Bavaria, 2017–2024, from 1.13 TB of Sentinel-2 L3A composites masked with yearly 10 m crop type maps, aggregated with exact partial-pixel zonal statistics on the GPU. The Sentinel-2 half of a two-person MSc capstone. A side analysis matches Sentinel-2 reflectance to OCO-2 solar-induced fluorescence footprints.

Master's thesis

Carried out at the DLR Earth Observation Center, Oberpfaffenhofen, on the detection of greenhouses and plastic-covered parcels in southern Germany from 20 cm aerial orthophotos, with no hand-drawn annotation anywhere in training. Labels were derived from EU parcel-level crop declarations and refined against the imagery. The detector combines a frozen satellite-pretrained DINOv3 backbone, decoded back to 20 cm by guided feature upsampling, with a trainable ResNet-34 branch and a small fusion head. Supervised by Dr Ursula Gessner (DLR) and Prof Dr Iftikhar Ahmed (UE). A paper is in preparation.

How I work

Most of my projects derive training labels from registers or benchmarks that were never made for the purpose, then deal with the biases those labels carry. A result that has come back in every project so far is that, past a small model budget, improving the data moves accuracy further than adding model capacity does, and I measure both sides rather than assume it. Pipelines are numbered stages with pinned environments so someone else can rerun them, and evaluation is on sites and conditions held out from training, not on random splits.

Experience

  • Student Assistant, Robotics and Perception, TU Berlin, 2025–2026. Onboard image capture and control components in Python for REINCARNATE, a Horizon Europe consortium project.
  • Test Engineer, Infosys, India, 2021–2024. Automated test pipelines in Java and JavaScript with Selenium and TestNG, and data validation in SQL.

Education

  • M.Sc. Data Science, University of Europe for Applied Sciences, Potsdam, 2024–2026.
  • B.Eng. Electronics and Communication Engineering, Jaypee Institute of Information Technology, India, 2016–2020.

Tools

Python, PyTorch, C++17 (CMake, pybind11), SQL. GDAL, rasterio, geopandas, xarray, QGIS, Google Earth Engine, STAC. Linux, Git, Docker, pinned environments. GPU training on A100 and HPC on LRZ terrabyte (SLURM).

Contact

Figure data from CaFFe (Gourmelon et al. 2022, CC BY 4.0), Glacial-Lake-Bench (Kaushik et al., CC BY 4.0), FZI-AURA, LEVIR-CD, the OWL caribou survey release (CC BY-NC-SA 4.0), DLR Sentinel-2 composites, and MARS-LVIG and UAVScenes (CC BY-NC-SA 4.0) with Copernicus GLO-30, ESA WorldCover, the Meta and WRI canopy height map, Sentinel-2 and OpenStreetMap contributors (ODbL).

Pinned Loading

  1. sar-transfer-glaciers sar-transfer-glaciers Public

    Do frozen image encoders transfer to SAR? Glacier calving fronts on CaFFe with frozen DINOv3 (satellite and photo), C-RADIO, TerraMind and SARATR-X and small heads, against a U-Net from scratch; pi…

    Jupyter Notebook

  2. Change-Detection-Using-Dinov3 Change-Detection-Using-Dinov3 Public

    Can frozen DINOv3 satellite embeddings find new buildings? Temporal transformer on SpaceNet-7 and LEVIR-CD, free Colab T4. Test F1 0.91 on LEVIR-CD, where a 0.56M-parameter difference head matched …

    Jupyter Notebook

  3. vggt-omega-aura-benchmark vggt-omega-aura-benchmark Public

    Where does VGGT-Omega fail on real driving data? Depth and camera-pose error on FZI-AURA, split by moving vs parked objects, rain and night. Python reference + C++ core, 394 scenes scored, every nu…

    Jupyter Notebook

  4. owl-caribou-overhead owl-caribou-overhead Public

    Cross-herd, cross-year evaluation of four overhead caribou detectors on CAH 2022 aerial survey patches, with error bars, failure analysis and threshold sweeps

    Jupyter Notebook

  5. sar-transfer-distillation sar-transfer-distillation Public

    Can a distilled student match its frozen teachers on radar? Part four of a SAR transfer series. A C-RADIO-style ViT-B student learns from SigLIP2, satellite DINOv3, PE-Spatial and TerraFM-B reading…

    Python

  6. uav-lidar-vs-satellite uav-lidar-vs-satellite Public

    Raw drone LiDAR logs from MARS-LVIG turned into DSM, DTM and land cover at 0.5 m, checked against Copernicus DEM, ESA WorldCover, a global canopy height map, Sentinel-2 and OpenStreetMap

    Python