the PACE OCI Toolkit (the PACE Toolkit)

Summary

This is a set of JavaScript-based Google Earth Engine 🌎 (GEE) tools for accessing land data from the Ocean Color Instrument (OCI) sensor on NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite 🛰️. One of the dependency packages provides direct access to PACE OCI provisional surface reflectance (SR) and vegetation index (VI) data that have been loaded into GEE. Another dependency package provides data on the hyperspectral wavelengths of the PACE OCI surface reflectance bands, as well as the wavelengths of NASA's other spaceborne hyperspectral imagers, namely EO-1 Hyperion and the ISS EMIT, for comparison. Aside from the dependencies, example scripts are provided to allow users to interact with the data, and the geographic and temporal scopes of those examples can be modified to meet users' needs.

Functions

The scripts are divided into the following main functions:

(i) Data discovery (for discovering which PACE OCI SR and VI data are available, as well as which EO-1 Hyperion and EMIT data are available)

(ii) Data visualization (for viewing PACE OCI SR and VI data are available, as well as viewing available EO-1 Hyperion and EMIT data)

(iii) Spectral signature visualization (for extracting and viewing the spectral signatures of specific land cover or vegetation features)

(iv) Data gap filling (for filling data gaps using averages or using harmonic functions)

(v) Time series analysis (for viewing the time series of SR or VI data)

(vi) Image classification (for basic unsupervised learning classification of PACE OCI data)

📢 Add this repo to Google Earth Engine 📢

To add the code repository 💾 directly to your GEE account, use the following bit.ly 🔗: https://bit.ly/geerepopace_oci.

Additional information

1. A changelog focusing on the updates to the PACE OCI data is being maintained and regularly updated.
2. More information on the PACE Land data Users' Group (PLUG) can be found at: https://pace.oceansciences.org/event_archive/landDataUserGroup.htm.
3. More information on PACE's data products can be found at: https://pace.oceansciences.org/data_table.htm.

1. Explore the PACE OCI hyperspectral signatures using the PACE OCI Hyperspectral Data Explorer, based on the awesome Planet Tanager Viewer developed by Dr. Sam Roy: https://servirbz.users.earthengine.app/view/pace-oci-spectral-viewer-v1.

1. Videos 🎥 featuring the PACE OCI Toolkit are available in the following recordings:

• [1 July 2025] The 2nd PACE Land data Users' Group (PLUG) meeting: https://youtu.be/hOu8rPd_x6I?t=1779.
• [22 July 2025] The 2nd day of the NASA Earthdata webinar on the Fundamentals of Hyperspectral & Thermal Earth Observations: https://youtu.be/0JuN_raCcvk?t=8827.
• [6 August 2025] The pre-AmeriGEO Week 2025 webinar on PACE and GEE: https://youtu.be/nOXNXBQR3cw?t=8142.
• [19 August 2025] A general PACE OCI Toolkit overview: https://youtu.be/8Ln6CMkyv00.

Methods: Workflow for getting PACE OCI land data into GEE

The following is a graphical representation of the process for ingesting the PACE OCI land data into GEE. An R script was used for batch processing of the PACE OCI vegetation index data that were ingested into GEE.

Acknowledgements

This work was initially soft-launched on 22 May 2025, during the virtual Technical Interchange Meeting of NASA's Surface Biology and Geology (SBG) mission. This work is being led by researchers from the Lab for Applied Science of the Earth System Science Center of the University of Alabama in Huntsville and has been supported by the NASA Earth Action / NASA Marshall Space Flight Center. This work is being done in the context of an Early Adopters project for PACE. The PACE Mission Applications Lead, Dr. Morgaine McKibben (NASA / SSAI), is acknowledged for her support, as are Skye Caplan (NASA / SSAI) of the PACE mission, and Dr. K. Fred Huemmrich of the PACE Science & Applications Team (NASA / UMBC). Kudos are also due to Kelsey Herndon (NASA / UAH), Prof. Rob Griffin, Dr. Africa-Flores-Anderson (NASA), Eric Anderson (NASA), Dr. Kevin Horn (NASA), Dr. Ashutosh Limaye (NASA), and Dan Irwin (NASA) of NASA MSFC. This work also draws inspiration from the GEE Toolkit for water quality monitoring developed by Dr. Ileana Callejas et al. (2022), and pioneering work done by Dr. Gennadii Donchyts (formerly of Deltares, and currently at Google) in developing various add-on functions for GEE.

Citation

If this toolkit is used in publications, presentations, or other venues, please cite 📝 the following:

Cherrington, E. (2025). PACE OCI data Toolkit (Version 1.0.0.1) [Computer software]. https://doi.org/10.5281/zenodo.15873995

Contact information

If you have any questions, feel free to contact Emil Cherrington by :envelopewitharrow: email: emil.cherrington [at] uah.edu.