Add script for ‘AQDM.get.data’ function
Add require statement (for RCurl)
Set the start year and end year for data retrieval
Access URI stub for obtaining station metadata
Add URI stub for EPA air quality data
Create vector list of available AQ parameters
Get updated station data for each of the monitoring networks
Create data frame for the NO2 parameter
Create data frame for the ozone parameter
Add test data for filtering list by several bounding boxes
Create subsets of the ‘NO2_station_metadata’ df by bbox
Combine the subsets by bounding box into one subset
Filter stations not with starting date before requested
Filter stations not with ending date after that requested
Select only stations using FEM or FRM methodologies
Get unique set of ‘AQS.Site.ID’ values for NO2 stations
Get count of stations for NO2
Create subsets of ozone station metadata by bounding boxes
Combine several subsets into one using rbind
Conduct subset of stations not within requested years