TY - JOUR
T1 - Using Vehicles' Rendezvous for in Situ Calibration of Instruments in Fleet Vehicle-Based Air Pollution Mobile Monitoring
AU - Xiang, Jianbang
AU - Austin, Elena
AU - Gould, Timothy
AU - Larson, Timothy
AU - Yost, Michael
AU - Shirai, Jeffry
AU - Liu, Yisi
AU - Yun, Sukyong
AU - Seto, Edmund
N1 - Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/4/7
Y1 - 2020/4/7
N2 - This study examines the feasibility of the in situ calibration of instruments for fleet vehicle-based mobile monitoring of ultrafine particles (UFPs) and black carbon (BC) by comparing rendezvous vehicle measurements. Two vehicles with identical makes and models of UFP and BC monitors as well as GPS receivers were sampled within 140 m of each other for 2 h in total during winter in Seattle, Washington. To identify an optimal intervehicle distance for rendezvous calibration, 6 different buffers within 0-140 m for UFP monitors and 5 different buffers within 0-90 m for BC monitors were chosen, and the results of calibration were compared against a reference scenario, which consisted of mobile colocation measurements with both sets of the UFP and BC monitors deployed in one of the vehicles. Results indicate that the optimal distances for rendezvous calibration are 10-80 m for UFP monitors and 0-30 m for BC monitors. In comparison with the mobile colocation calibration, the rendezvous calibration shows a normalized root mean squared deviation of 6-14% and a normalized mean absolute deviation of 4-8% for these monitors. Criteria for applying a rendezvous calibration approach are presented, and an extension of this approach to an instrumented fleet of mobile monitoring vehicles is discussed.
AB - This study examines the feasibility of the in situ calibration of instruments for fleet vehicle-based mobile monitoring of ultrafine particles (UFPs) and black carbon (BC) by comparing rendezvous vehicle measurements. Two vehicles with identical makes and models of UFP and BC monitors as well as GPS receivers were sampled within 140 m of each other for 2 h in total during winter in Seattle, Washington. To identify an optimal intervehicle distance for rendezvous calibration, 6 different buffers within 0-140 m for UFP monitors and 5 different buffers within 0-90 m for BC monitors were chosen, and the results of calibration were compared against a reference scenario, which consisted of mobile colocation measurements with both sets of the UFP and BC monitors deployed in one of the vehicles. Results indicate that the optimal distances for rendezvous calibration are 10-80 m for UFP monitors and 0-30 m for BC monitors. In comparison with the mobile colocation calibration, the rendezvous calibration shows a normalized root mean squared deviation of 6-14% and a normalized mean absolute deviation of 4-8% for these monitors. Criteria for applying a rendezvous calibration approach are presented, and an extension of this approach to an instrumented fleet of mobile monitoring vehicles is discussed.
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U2 - 10.1021/acs.est.0c00612
DO - 10.1021/acs.est.0c00612
M3 - Article
C2 - 32150678
AN - SCOPUS:85083002883
SN - 0013-936X
VL - 54
SP - 4286
EP - 4294
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 7
ER -