AOP Data Availability Notification – Release 2026

As part of the upcoming 2026 NEON Annual Release, AOP is in the process of updating data products with known quality issues, as well as standardizing L3 discrete lidar data and metadata products. Major planned AOP quality updates are summarized in Tables 1 and 2 below. 

We recommend deferring the download of L3 Lidar data products, as well as the AOP data products summarized in Table 1 until the end of January 2026 (when RELEASE-2026 becomes available).

AOP Data Availability between Dec 2025 - Jan 2026

There will be an approximately 6 week period between December 15, 2025 and ~January 30, 2026 (when RELEASE-2026 becomes available) where the data availability chart on the NEON data portal may not reflect the true availability of the products for the Discrete Lidar data products as well as the released sites listed in Table 1. Neither the RELEASE-2025 tag nor the DOIs for the released data products listed will be applicable during this period due to the changing data content. We recommend deferring  downloading the listed AOP data products in Table 1 during this interim period. If you require AOP data from Table 1 during this time period, please use the NEON Contact Us form to request the status of a given data product, site, and year. The 2026 Release is estimated to be complete by the end of January 2026, and at that time, all AOP data from RELEASE-2025 will be “tombstoned” and superseded by RELEASE-2026. For more information on the release process as it pertains to AOP, please refer to the AOP Release Process section of NEON's Data Product Revisions and Releases page. 

We also encourage you to visit the new tutorial Understanding AOP Data Releases and Best Practices for AOP Data Management for more details. This tutorial demonstrates some of the tools in the Python neonutilities package pertaining to AOP data releases, citation, and data management. Note that downloading AOP data via the neonutilities packages will also be subject to the availability interruptions between Dec. 2025-Jan. 2026, as described above. 

Explanation of AOP Data Quality Updates for RELEASE-2026

The majority of AOP data quality issues that will be fixed for RELEASE-2026 fall into one the categories listed below. For additional details, refer to the data product issue logs for individual AOP data products on the Data Portal.

• Mis-alignment in the L1 lidar line to line adjustments
  • Alignment is a step in the Lidar L1 processing which adjusts adjacent flight lines to ensure consistency between lines. This data issue also affected downstream camera and reflectance data products which rely on the DSM generated from the Lidar data for orthorectification. Starting in 2020, AOP started using the Bayes StripAlign software to perform these flightline adjustments, as it was found to provide better results than the software solutions previously used. Some of the earlier (pre-2020) AOP collections were found to have poor alignments between lidar flightlines in portions of the site, increasing geolocation error, which could be on the order of tens of centimeters up to meters of vertical differences between lines.
• Partially missing data (GRSM 2017, NOGP 2017).
• DTM horizontal offset (2017 D08 and D11 sites).

In addition to addressing these quality issues, some more minor data and metadata updates will be made to the L3 Lidar data products (DP3.30015.001, DP3.30024.001, DP3.30025.001), as summarized below:

• Standardizing the L3 lidar geotiff format to be consistent with tiff files generated in the past 2 years (2024 and 2025). These new geotiff files include LZW compression and standard geotiff tags and are generated with Python GDAL library
• Removing L3 geotiff files that were entirely comprised of no data values (more prevalent in earlier years).
• Fixing metadata file names that do not follow the standard naming conventions and standardizing metadata file organization.
• Adding missing metadata files (QA reports, uncertainty lidar).
• Replacing L3 tile boundary shapefiles and kmls, previously generated for each tile, with a single merged shapefile boundary file derived from the L3 discrete lidar products (instead of the L3 classified point cloud data).

Table 1: Planned AOP data quality updates for RELEASE-2026 that are currently included in RELEASE-2025

Table 2: Planned AOP data quality updates for RELEASE-2026 that are currently PROVISIONAL

As part of the upcoming Data Release, only discrete lidar data products (DP1.30003.001, DP3.30015.001, DP3.30024.001, DP3.30025.001) and RGB camera data products (DP1.30010.001, DP3.30010.001) will be re-processed to correct for the data quality issues related to orthorectification, continue reading for more information about the planned status of the AOP reflectance data products in 2026.

Status of AOP Reflectance Data Products (Directional and Bidirectional) in 2026

As of 2024, NEON began publishing bidirectional reflectance data products, which include BRDF (Bidirectional Reflectance Distribution Function) and topographic corrections. These corrected L1 reflectance and derived (L2-L3) reflectance data products are currently available provisionally under a separate revision (.002) for AOP data collected between 2022-2025. Level 1 (L1; delivered by flightline) directional reflectance is still available (DP1.30006.001) in addition to the L1 bidirectional reflectance (DP1.30006.002). 

All bidirectional data will continue to be available only provisionally in 2026 and will not be included in RELEASE-2026. A rare numerical instability  in the BRDF correction was recently discovered, only affecting pixels in heavily shaded / water areas. The issue resulted in anomalous spikes in the spectral curve, and affects a small percentage (typically well under 3%) of pixels for each site, primarily occurring in shadowed regions or dark water bodies that are characterized by a low signal to noise ratio.   AOP scientists are implementing an additional masking routine to  remove these pixels from the BRDF correction routine and avoid the anomalies. For this reason we will keep the bidirectional reflectance datasets in Provisional status in 2026. Stay tuned for a data notification providing more information about this issue in the coming weeks.

Starting in early 2026, AOP plans to back-process earlier years of reflectance data (2013-2021) to include the BRDF and topographic corrections; eventually, all of the directional reflectance products will be replaced by the bidirectional reflectance data. As part of this planned re-processing effort, any original reflectance data products (.001 revisions) for the sites with known orthorectification issues will be updated in 2026 and are currently planned to be included in RELEASE-2027.

Updates to AOP data on Google Earth Engine in 2026

Once RELEASE-2026 is available, the AOP team will update the Image Collections on Google Earth Engine (GEE) to provide the updated datasets from the 2026 release. We expect this to be complete by February 20, 2026. If you are using AOP data on GEE, please check the PROVISIONAL_RELEASED and RELEASE_YEAR properties for each image to make sure you are using the most recent data and citing the data properly.

For any inquiries, please use the Contact Us form.