Paired quality assurance and operational field data from the northern region of the U.S. Forest Inventory and Analysis program

This publication includes collected forest measurement and quality assurance (QA) data used to quantify measurement uncertainty within the data collected by the Northern Region of the USDA Forest Service, Forest Inventory and Analysis (FIA). Field data were collected for the FIA program by the field crew and then the quality assurance crews collected data on the same trees and plots in order to examine bias and assess compliance with measurement quality objectives. The data in this publication include both the FIA and QA measurements from a recent inventory cycle from 2011 to 2016 with measurements occurring from October 2010 to April 2017, depending on the state.
The FIA program has a quality assurance program to assess the repeatability and quality of field measurements. A subset of field measurements are remeasured by QA field crews, who have extensive supervisory, training, and field experience, ideally within three weeks of the original measurements, on at least 4% of plots (Gormanson et al. 2017; Pollard et al. 2006; USDA 2019). These are conducted as “blind checks,” meaning that the QA crew does not view the measurements conducted during the earlier plot visit by the field crew. Although the primary purpose of the QA program has been to evaluate and improve field crew performance, the difference between the two measurements is a rich source of data for quantifying uncertainty in a wide variety of forest measurements.
For more information about these data, see Yanai et al. (2022).

This data package was published on 01/25/2023. On 08/27/2025 we corrected the publication year, which was incorrectly set to 2022, to 2023.

本数据集收录了经整理的森林测量数据与质量保证（QA）数据，用于量化美国农业部（USDA）林业局北部区域森林资源清查与分析（FIA）项目所采集数据中的测量不确定性。野外工作组先为FIA项目采集野外数据，随后质量保证工作组会对同一批林木与样地开展数据采集，以检验测量偏差并评估是否符合测量质量目标要求。本数据集收录的FIA与QA测量数据，来自2011至2016年的最新一轮清查周期，实际测量工作依各州情况从2010年10月持续至2017年4月。

FIA项目设有质量保障计划，用于评估野外测量的可重复性与质量。质量保证野外工作组会对至少4%的样地进行复测，该工作组具备丰富的管理、培训与野外实践经验，理想情况下会在原始测量完成后的三周内开展复测（Gormanson等，2017；Pollard等，2006；USDA，2019）。此类复测以“盲检”形式开展，即质量保证工作组无法获知野外工作组此前在样地调查中完成的测量结果。尽管质量保障计划的核心目标是评估并提升野外工作组的作业水平，但两次测量的差值可作为丰富的数据来源，用于量化各类森林测量中的不确定性。

如需了解该数据集的更多细节，请参阅Yanai等（2022）。

本数据包于2023年1月25日发布。2025年8月27日，我们更正了此前误设为2022年的发布年份，修正为2023年。