frost_assembler: download MET Norway in-situ data and format the output

In metno/gibson: get in-situ observations

download MET Norway in-situ data and format the output

Description

The data are downloaded by using gibson_frost that is linked to the Frost API (frost.met.no).

The output is formatted and presented as a data frame where every row includes all the metadata and the observations for a specific source/timestamp.

The function has been implemented and tested to download hourly and diurnal data.

Usage

frost_assembler(client_id=NULL,
                oldElementCodes=NULL,
                start_date=NULL,
                stop_date=NULL,
                format="
                formatOUT="
                countries="NO",
                spatial_extent=c(4,34,54,72),
                stationholders=NULL,
                stationholders.exclude=F,
                WMOonly=F,
                WMOin=T,
                na.rm=T,
                url.show=F,
                coords=data.frame(x="lon",y="lat",
                       proj4="+proj=longlat +datum=WGS84",
                       stringsAsFactors=F),
                verbose=F
                )

Arguments

client_id	character string with the API Client ID https://frost.met.no/auth/requestCredentials.html
oldElementCodes	character vector with the abbreviations used to define weather and climate elements (before Frost-era). See Details for more information or https://frost.met.no/elementtable.
start_date	character string with the time stamp of the first observation
stop_date	character string with the time stamp of the last observation
format	charater string specifying the date-time format of start_date and stop_date (see strptime help page)
formatOUT	charater string specifying the date-time format of the output timestamps (see strptime help page)
countries	character vector with the abbreviations of the countries. Only data sources located in those countries will be returned.
spatial_extent	numeric vector of the form c(long_min,long_max,lan_min,lan_max) that identifies a rectangle used to select the data sources. The lower left corner is (long_min,lan_min) the upper right corner is (long_max,lat_max).
stationholders	character vector with the names of the station holders
stationholders.exclude	logical, it is used in combination with stationholders If FALSE, then the stationholder list will be used to select the station holders to include in the output. If TRUE, then the stationholder list will be used to select the station holders NOT to include in the output.
WMOonly	logical, if TRUE then only WMO stations (i.e., having a WMO code) will be returned
WMOin	logical, used only if WMOonly=FALSE. if TRUE then WMO stations (i.e., having a WMO code) will be returned otherwise the will not.
na.rm	logical, if TRUE remove NAs from the output
url.show	logical, if TRUE the urls are shown to the user
coords	data frame specifying the coordinate reference systems (as proj4 strings http://proj4.org/) to include in the output together with the names of the easting and northing coordinate.
verbose	logical, if TRUE verbose mode is activated

Details

oldElementCodes abbreviations are listed at https://frost.met.no/elementtable. Not all abbreviations have been implemented (see frost_translate_oldElementCodes).

It is not possible to mix variables with hourly time resolution and variables with daily time resolution.

SourceId is the data source identifier of an observation. From the documentation on frost.met.no: \"The ID(s) of the data sources to get time series for as a comma-separated list of Frost API station IDs: SN<int>[:<int>|all] (e.g. SN18700, SN18700:0, or SN18700:all). 0 is the main sensor and x≥1 is a parallel sensor.\"

The coordinate reference systems (CRS) are specified by means of proj4 strings http://proj4.org/. A list of proj4 string can be found at http://spatialreference.org/. Further details on the coordinate conversion can be found at crs_transform. It is possible to specify more than one CRS to be included in the output. The coordinate transformation is based on functions available through the packages sp, rgdal.

The output variables have the same names of the oldElementCodes and the KDVH quality codes are also returned. The quality code meanings are available at this link https://frost.met.no/observations/availableQualityCodes/v0.jsonld?lang=nb-NO.

The observation timestamp (UTC) mark the end of the aggregation period.

Value

A data frame is returned. The number of columns depends on the input parameters. Each row includes all the metadata and observed values for a single sourceId/timestamp.

The column names are: timestamp (end of the aggregation period), sourceId (station:sensor), easting coordinate for the 1st CRS, northing coordinate for the 1st CRS, easting coordinate for the 2nd CRS, northing coordinate for the 2nd CRS, ... , z (elevation a.m.s.l.), variable1, variable1_qcode, variable2, variable2_qcode, ...

Note

The R-packages sp and rgdal are needed for the coordinate conversions.

Author(s)

Cristian Lussana

See Also

gibson_frost crs_transform

Examples

# load libraries
library(gibson)
#
auth<-put_your_ClientID_here
# get hourly precipitation and temperature for all Norwegian stations, add coordinates
#  transformed over several CRSs
d<-frost_assembler(client_id=auth,oldElementCodes=c("RR_1","TA"),start_date="2018-03-08T01:00",stop_date= "2018-03-10T01:00",format="%Y-%m-%dT%H:%M",formatOUT="%Y-%m-%dT%H",countries="NO",spatial_extent=c(4,34,54,72),stationholders=NULL,stationholders.exclude=F,WMOonly=F,na.rm=T,url.show=T,coord=data.frame(x=c("lon","x_lcc","x_utm33","x_laea"),y=c("lat","y_lcc","y_utm33","y_laea"),proj4=c("+proj=longlat +datum=WGS84","+proj=lcc +lat_0=48 +lon_0=8 +lat_1=48  +lat_2=48 +a=6371229 +no_defs","+proj=utm +zone=33 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0","+proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000 +ellps=GRS80 +units=m +no_defs"),stringsAsFactors=F),verbose=T)

#dowload 1 hour for several hourly variables
d<-frost_assembler(client_id=put_your_ClientID_here,oldElementCodes=c("FF","PR","TA","DG","DD","RR_1","FG","UU"),start_date="2018-03-08T13:00",stop_date= "2018-03-08T13:00",format="
#dowload 1 hour for several hourly variables but only for MET.NO and WMO stations
d<-frost_assembler(client_id=put_your_ClientID_here,oldElementCodes=c("FF","PR","TA","DG","DD","RR_1","FG","UU"),start_date="2018-03-08T13:00",stop_date= "2018-03-08T13:00",format="

metno/gibson documentation built on Feb. 12, 2024, 7:25 a.m.