Estimating Bias within the National
Atmospheric Deposition Program and the National Trends Network Last Updated: September 28, 1995 Approach: As there is no `standard' network against which the NADP/NTN monitoring program can be measured, the network has attempted to estimate bias by comparing NADP/NTN data to those of other similar networks. This comparison is being accomplished through the collection and analysis of data from other networks that have located there sampling equipment within 30 meters of NADP/NTN sampling equipment. This type of collocation however, only identifies systematic differences between the collocated networks. Collocated equipment precision (random error) must also be known so that overall network measurement error can be estimated as the sum of the systematic and random error. This approach follows in part, the general framework of collaborative testing outlined by Youden (1967).
Chemical Analysis
and Rain Gage Volumes: ![]() Environmental Protection Agency. 1990. Progress Report: Comparison of Precipitation Measurements by Nipher-Shielded and Standard Belfort Recording Rain Gages at NADP/NTN Sites. EPA 600-3-90-064. Bigelow, D.S., A.S. Denning, and J. Baron. 1990. Differences Between Nipher and Alter Shielded Universal Rain Gages at Two Colorado Deposition Sites. Environmental Science and Technology, 24, (5), pp 758-760.
![]() ![]() Graham, R.C.; Obal, J. 1989. The Non-parametric Statistical Evaluation of Precipitation Chemistry Sampler Intercomparison Data; Atmos. Environ., 23, 1117-1130. Graham, R.C.; Robertson, J.K. 1990. An Assessment of Performance of Wet Atmospheric Deposition Samples. U.S. Geological Survey; Reston, VA. Water-Resources Investigations Report 90-4042. Graham, R.C.; Robertson, J.K.; Obal, J. 1987. An Assessment of the Variability in Performance of Wet Atmospheric Deposition Samples. U.S. Geological Survey; Denver, CO. Water-Resources Investigations Report 87-4125. Graham, R.C.; Robertson, J.K.; Schroder, L.J.; Lafemina, J. 1988. Atmospheric Deposition Sampler Intercomparison; Water, Air, Soil Pollut. 37, 139-147. |