The station longitude and latitude data provided by ISC seismic phase travel time is inconsistent with the station longitude and latitude data provided by IRIS, GFZ, IPGP and other servers?
hello everyone. I now have some seismic phase travel time data downloaded from the ISC (The International Seismological Centre), which provides the longitude and latitude coordinates of each station but does not provide the network name.So I want to use clients. fdsn get_ stations () obtains the corresponding STATIONTXT file, and then filters the data in this file to obtain the minimum difference between longitude and latitude coordinates provided by ISC as the network name.
I found that the longitude difference (dlo) of most stations is very small, which can be accurate to 1E-04 °; However, the latitude difference (dla) is relatively large, which can only reach 1E-01 °, and this problem is not an accidental problem.
network | station | stalo | cli_lo | dlo | stala | cli_la | dla | stael |
---|---|---|---|---|---|---|---|---|
GE | KBS | 11.942 | 11.9417 | 0.0003 | 78.853 | 78.925598 | -0.072598 | 0.074 |
GE | KBS | 11.942 | 11.9417 | 0.0003 | 78.853 | 78.925598 | -0.072598 | 0.074 |
NO | SPB4 | 16.348 | 16.34819 | -0.00019 | 78.101 | 78.178909 | -0.077909 | 0.34 |
NO | JMIC | -8.505 | -8.5057 | 0.0007 | 70.867 | 70.986603 | -0.119603 | 0.158 |
SY | SCO | -21.95 | -21.950001 | 1.00E-06 | 70.361 | 70.483299 | -0.122299 | 0.069 |
GE | SUMG | -38.454 | -38.453899 | -0.000101 | 72.466 | 72.576302 | -0.110302 | 3.275 |
IU | KEV | 27.007 | 27.0035 | 0.0035 | 69.63 | 69.7565 | -0.1265 | 0.08 |
IU | KEV | 27.007 | 27.0035 | 0.0035 | 69.63 | 69.7565 | -0.1265 | 0.08 |
NO | ARA0 | 25.506 | 25.505779 | 0.000221 | 69.408 | 69.534859 | -0.126859 | 0.403 |
IM | ARCES | 25.506 | 25.5058 | 0.0002 | 69.408 | 69.534897 | -0.126897 | 0.403 |
network: name of the network to be matched
station: station name provided by ISC
stalo: longitude coordinate provided by ISC
cli_ lo: using get_ Station longitude of the best match obtained by stations ()
dlo: difference between ISC longitude and best matched station longitude
stala: latitude coordinates provided by ISC
cli_ la: using get_ Station latitude of the best match obtained by stations ()
dla: difference between ISC latitude and best matched station latitude
stael: elevation information provided by ISC
Shouldn’t the longitude and latitude coordinates of the same station be identical? Which unit of data should I use?