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  MADIS Frequently Asked Questions

MADIS Frequently Asked Questions


Frequently Asked netCDF Questions


Question:

What if there are missing variables in the NetCDF files?

Answer:

In the static/ directory there are 2 files: sfctbl.txt and sfcvcn.txt, where sfcvcn.txt maps the name to a number and sfctbl.txt maps the number to a netcdf variable. If the variable you are looking for is not in these files, it is missing.

Question:

I'm using MADIS data in data assimilation experiments. At hour HH, an hourly surface file at HH contains data from HH + 15m to HH + 44m and an hourly ACARS file at HH contains data from HH + 00m to HH + 59m. Can someone tell me the time range of obs contained in the hourly rawin file?

Answer:

It is in: point/roab/netcdf
It's end time is: HH + 00m to HH + 59m
To tell a MADIS file end time, "ncdump -h" the file.
The fileEndOffset list the endtime.
fileEndOffset = 3599 would be minute 59 second 59.
fileEndOffset = 2699 would be minute 44 seconf 59.
You asked a good question. This is more information than you asked for, in part to give our docs people the full answer in case someone else asks a similar question.
The MADIS data files don't have one common relationship to the filename and the times in the file. This is due to MADIS using the convention of the data where possible. For example profiler data is timestamped at the end of the time range and metar is 15 minutes into the time range. Here are the MADIS data files and the time ranges for them. Time range end compared to file name MADIS File:
Endtime: 59 minutes 59 seconds /LDAD/crn/netCDF/
Endtime: 59 minutes 59 seconds /LDAD/hcn/netCDF/
Endtime: 59 minutes 59 seconds /LDAD/OMO/netCDF/
Endtime: 59 minutes 59 seconds /LDAD/hydro/netCDF/
Endtime: 59 minutes 59 seconds /LDAD/mesonet/netCDF/
Endtime: 59 minutes 59 seconds /LDAD/nepp/netCDF/
Endtime: 59 minutes 59 seconds /LDAD/urbanet/netCDF/
Endtime: 59 minutes 59 seconds /LDAD/snow/netCDF/
Endtime: 59 minutes 59 seconds /point/acars/netcdf/
Endtime: 59 minutes 59 seconds /point/acarsProfiles/netcdf/
Endtime: 59 minutes 59 seconds /point/POES/netcdf/
Endtime: 59 minutes 59 seconds /point/radiometer/netcdf/
Endtime: 59 minutes 59 seconds /point/raob/netcdf/
Endtime: 59 minutes 59 seconds /point/satrad/netcdf/
Endtime: 44 minutes 59 seconds /point/metar/netcdf/
Endtime: 44 minutes 59 seconds /point/maritime/netcdf/
Endtime: 44 minutes 59 seconds /point/sao/netcdf/
Endtime: 29 minutes 59 seconds /point/HDW1h/netcdf/
Endtime: 29 minutes 59 seconds /point/HDW/netcdf/
Endtime: 0 minutes 0 seconds /point/profiler/netcdf/
Endtime: 0 minutes 0 seconds /LDAD/profiler/netCDF/



Last updated 16 June 2016