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).