Difference between revisions of "Questions and Comments about CF-1.6 Station Data Convention"
From Earth Science Information Partners (ESIP)
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The objective of this page is to promote discussion about CF-netCDF formats for station point data. | The objective of this page is to promote discussion about CF-netCDF formats for station point data. | ||
| − | == | + | == CSV, Comma Separated Values: Its Uses and Limitations == |
| − | + | CSV format is easy, compact and practical for many uses.It can be fed to any spreadsheet and consumed easily with custom software. | |
<html><a href="http://data1.datafed.net:8080/AQS?Service=WCS&Version=1.1.2&Request=GetCoverage&Identifier=AQS_H&Format=text/csv&Store=true&TimeSequence=2007-05-12/2007-05-12T06:00:00/PT1H&RangeSubset=pm25nr[location[350439004,350610008]]&BoundingBox=-130,24,-60,50,urn:ogc:def:crs:OGC:2:84">Example of WCS GetCoverage query returning an envelope with uri to the result CSV file</a></html> | <html><a href="http://data1.datafed.net:8080/AQS?Service=WCS&Version=1.1.2&Request=GetCoverage&Identifier=AQS_H&Format=text/csv&Store=true&TimeSequence=2007-05-12/2007-05-12T06:00:00/PT1H&RangeSubset=pm25nr[location[350439004,350610008]]&BoundingBox=-130,24,-60,50,urn:ogc:def:crs:OGC:2:84">Example of WCS GetCoverage query returning an envelope with uri to the result CSV file</a></html> | ||
| + | |||
| + | |||
| + | Trimmed result: | ||
| + | |||
| + | loc_code,lat,lon,datetime,pm25nr, etc... | ||
| + | 350610008,34.81,-106.74,2007-05-12T00:00:00,3.8, etc... | ||
| + | 350439004,35.62,-106.72,2007-05-12T00:00:00,20.9, etc... | ||
| + | 350610008,34.81,-106.74,2007-05-12T01:00:00,6.9, etc... | ||
| + | |||
| + | Unfortunately, the format makes embedding metadata in a CF-like convention difficult. | ||
| + | |||
| + | * Location dimension: | ||
| + | ** Incompleteness: No idea what else is known about the stations than loc_code, lat and lon. | ||
| + | ** Inefficient: Repetition of the same latitude and longitude values. | ||
| + | |||
| + | * Time dimension: | ||
| + | ** What's the periodicity? The software needs to guess, that AQS_H actually is hourly data. | ||
| + | ** Are all the locations in the same periodicity, or do the locations have individual recording times? Again a guess. | ||
| + | ** What was the requested time min + max, and what's the real returned time range. | ||
| + | |||
| + | There's field '''pm25nr''' but [http://data1.datafed.net:8080/AQS?Service=WCS&Version=1.1.2&Request=DescribeCoverage&Identifiers=AQS_H there's more about it]. It's PM 2.5 Non-Reference Method, units are ug/m3, source is from EPA Air Quality Network. | ||
Revision as of 11:15, August 29, 2011
The objective of this page is to promote discussion about CF-netCDF formats for station point data.
CSV, Comma Separated Values: Its Uses and Limitations
CSV format is easy, compact and practical for many uses.It can be fed to any spreadsheet and consumed easily with custom software.
Example of WCS GetCoverage query returning an envelope with uri to the result CSV file
Trimmed result:
loc_code,lat,lon,datetime,pm25nr, etc... 350610008,34.81,-106.74,2007-05-12T00:00:00,3.8, etc... 350439004,35.62,-106.72,2007-05-12T00:00:00,20.9, etc... 350610008,34.81,-106.74,2007-05-12T01:00:00,6.9, etc...
Unfortunately, the format makes embedding metadata in a CF-like convention difficult.
- Location dimension:
- Incompleteness: No idea what else is known about the stations than loc_code, lat and lon.
- Inefficient: Repetition of the same latitude and longitude values.
- Time dimension:
- What's the periodicity? The software needs to guess, that AQS_H actually is hourly data.
- Are all the locations in the same periodicity, or do the locations have individual recording times? Again a guess.
- What was the requested time min + max, and what's the real returned time range.
There's field pm25nr but there's more about it. It's PM 2.5 Non-Reference Method, units are ug/m3, source is from EPA Air Quality Network.
