Phenocam Data User Manual

Authors: José M. Beltrán-Abaunza Lars Eklundh Contributors: Shangharsha Thapa

Lars Eklundh Release: 1.0 - draft

The SITES Spectral Phenocam Data User Manual provides comprehensive guidance for the installation and use of phenocam data for monitoring of vegetation phenology carried out by the Swedish Infrastructure for Ecosystem Science (SITES). This infrastructure operates high- resolution digital cameras to capture temporal dynamics of vegetation at stations spanning diverse Swedish ecosystems from the Arctic to temperate regions. The phenocam network serves as a critical tool for understanding vegetation responses to climate change, bridging the gap between ground-based observations and satellite remote sensing. The cameras provide continuous, automated monitoring that captures fine scale phenological transitions including leaf emergence, senescence, and snow dynamics. The system delivers four processing levels: L0 (raw images with EXIF metadata), L1 (quality- controlled imagery), L2 (vegetation indices and ROI statistics), and L3 (daily solar-weighted aggregates). Key metrics include Green Chromatic Coordinate (GCC), Red Chromatic Coordinate (RCC), and raw RGB channel values, all processed through standardized ROI (Region of Interest) analysis. The network employs Mobotix cameras (with some exceptions) mounted at standardized heights and orientations, with automated image capture every half an hour up to 2 hours during daylight. Processing pipelines include solar weighting corrections (based on Lambert's cosine law), automated quality assessment flagging poor visibility or extreme conditions, and SITES- compliant data formatting for seamless integration with the SITES Data Portal. All L2 and L3 products are openly accessible through the SITES Data Portal (https://data.fieldsites.se/portal/), following standardized naming conventions and metadata schemas. The system ensures interoperability across stations through rigorous protocols for platform naming, instrument IDs, and product codes. The phenocam data supports research on vegetation-climate feedback, phenological trend analysis, validation of satellite observations, and ecosystem productivity modelling. The high temporal resolution (sub-daily to daily) fills critical gaps in understanding rapid ecosystem responses to environmental changes. Creation Date: 2025 02 25 Last Modified: 2026-01-27