The geomagnetic field 1-minute digitized data in IAGA-2002 format, extracted from magnetograms at Memambetsu (MMB). We evaluated the differences between the digital data obtained from the fluxgate magnetometer and the values extracted from magnetograms during the period of August 1994. Standard deviation of the differences for 60-minutes were less than 0.2nT (for H,Z) or 0.02' (for D) in a ratio of 99.5%, 99.6% and 98.7% for H, Z and D components, respectively, according to the data from August 1994. The data from the 58th minute to the 2nd minute of every hour may include reading errors of less than 2 nT due to crossing with the time marks on the magnetogram. When a trace is overlapped with a baseline on the magnetogram, the missing value with 99999 may be embedded. For details, refer to 'Mashiko, N. et al., 2012: Digitization of bromide paper records to extract one-minute geomagnetic data. Proceedings of 1st ICSU-WDS conference "Global data for global science", Kyoto, 251-254.' [Available online at www.icsu-wds.org.]
Version:2.5.0
The geomagnetic field 1-minute digitized data in IAGA-2002 format, extracted from magnetograms at Memambetsu (MMB). We evaluated the differences between the digital data obtained from the fluxgate magnetometer and the values extracted from magnetograms during the period of August 1994. Standard deviation of the differences for 60-minutes were less than 0.2nT (for H,Z) or 0.02' (for D) in a ratio of 99.5%, 99.6% and 98.7% for H, Z and D components, respectively, according to the data from August 1994. The data from the 58th minute to the 2nd minute of every hour may include reading errors of less than 2 nT due to crossing with the time marks on the magnetogram. When a trace is overlapped with a baseline on the magnetogram, the missing value with 99999 may be embedded. For details, refer to 'Mashiko, N. et al., 2012: Digitization of bromide paper records to extract one-minute geomagnetic data. Proceedings of 1st ICSU-WDS conference "Global data for global science", Kyoto, 251-254.' [Available online at www.icsu-wds.org.]
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | GeneralContact | spase://IUGONET/Person/Chosaka.KMO-JMA |
As for digitized data extracted from magnetograms, the service allows the download of quasi-definitive geomagnetic data, which have been corrected for baseline variations.
Reference: MMB
One-minute values are calculated as averages of 7.62-second values, centered on the minute. Then one-minute values are calibrated using absolute values observed at a one-week interval. D(eastward+)[arc minute], H[nT], Z(downward+)[nT], F[nT]