Radiation Sensor Comparisons During Gate International Sea Trails Gist

Radiation Sensor Comparisons During GATE International Sea Trails (GIST)

Radiation sensors on two ships of the U.S.S.R., one of Mexico, and one of the U.S. were compared during the GATE International Sea Trials (GIST), 2-10 August 1973, near 20N, 60W. Pyranometer comparison showed that two instruments disagreed by 23%, but the remaining four pyranometers disagreed by less than 6%. The data also suggest the Yanishevsky and Eppley pyranometers have dissimilar cosine response characteristics which causes them to disagree by 4 mW cm−2 or less at low sun elevation angels. Pyheliometers on the fours ships were in agreement to within 1.7%. Two pyrgeometers (an Anström type and Eppley type) differed by only 1.3%. An analysis of the GIST data suggests that, if conditions during the main field experiment are the same as in GIST, the three-day comparison period should be sufficient to reduce random errors in pyranometer measurements to 0.8%. This will allow determination of systematic pyranometer errors to well within the 5% level specified by ISMG.

Radiation Sensor Comparisons During GATE International Sea Trails (GIST)

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