ex_mult_downloads.rst

Downloading data from multiple Instruments

Unlike most data sets, space weather index data sets often contain a combination of related indices. This means that data from multiple :pypysat.Instrument sub-modules may be available in a single file. Starting in :pypysatSpaceWeather version 0.1.0, this data is saved for all :pypysat.Instrument sub-modules when downloading any one of them. In this way, downloads are minimized and no data sets are hidden or thrown away. The following example returns both F_10.7and Ap forecasts from SWPC. Previously, this data was contained in :pypysatSpaceWeather.instruments.sw_f107, which does not contain Ap data for all tag values.

import pysat
import pysatSpaceWeather as py_sw

f107 = pysat.Instrument(inst_module=py_sw.instruments.sw_f107, tag='45day')
ap = pysat.Instrument(inst_module=py_sw.instruments.sw_ap, tag='45day')

# Test to see this data hasn't already been downloaded
assert (ap.today() not in f107.files.files) and (ap.today()
                                                 not in ap.files.files)

# Download both data sets using only one Instrument
f107.download(start=f107.tomorrow())
ap.download(start=ap.tomorrow())

# Show that both files have been downloaded
print(f107.files.files[f107.today()], ap.files.files[ap.today()])

This will yield f107_45day_YYYY-MM-DD.txt ap_45day_YYYY-MM-DD.txt, where YYYY-MM-DD is the day you run this example. The table below shows a list of the :pypysat.Instrument sub-modules and tags that download multiple data sets. When possible, the same tag has been used across :pypysat.Instrument sub-modules.

Remote Data Set	Platform	Name	Tag(s)	Inst ID(s)
GFZ Kp	SW	Kp	def, now
		Ap
		Cp
SWPC Daily DSD	SW	F107	daily
		Flare
		SSN
		SBField
SWPC Prelim DSD	SW	F107	prelim
		Flare
		SSN
		SBField
SWPC 3-day Solar-Geo	SW	F107	forecast
Predictions		Kp	prediction
		Ap
		StormProb
		Flare
		PolarCap
SWPC 3-day Geomag	SW	Kp	forecast
Forecast		Ap
		StormProb
SWPC Daily Geomag	SW	Kp	recent
		Ap
SWPC 45-day Forecast	SW	F107	45day
		Ap