A variety of satellite based instruments provide SO2 and particle data for volcanoes worldwide, including Hawaii:
1. Latest daily (OMI/OMPS) satellite images of SO2 massNASA
Site includes daily SO2 mass plus archived and time series data
2. Near real time OMI satellite images of SO2 massNOAA
Latest OMI SO2 column (5 km) images by volcano, plus cloud and aerosol index images.
http://satepsanone.nesdis.noaa.gov/pub/OMI/OMISO2/index.html
3. GOES-WEST satelliteNOAA
Used mostly for weather tracking, but also for volcanic gas emissions and lava flows. Images are acquired every 15 minutes.
http://www.ssd.noaa.gov/VAAC/kilauea/sloop-vis.html
4. MODIS satelliteNASA
Passes over Hawai’i twice a day, and can be useful for tracking plumes.
http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=AERONET_Mauna_Loa
5. SACS - Support to aviation control serviceConsortium hosted by Belgian Institute for Space Aeronomy
Subscription service for image notification of volcanic gas and particle events from 5 instruments (OMI; Gome2; IASI; AIRS; Sciamachy)
6. TropomiConsortium consisting of Airbus Defence and Space, KNMI, SRON and TNO
The TROPOspheric Monitoring Instrument (TROPOMI) has UV, UVIS, NIR and SWIR on board the Copernicus Sentinel-5 Precursor satellite which will come online later in 2016.
7. NASA Earth ObservatoryNASA
Various types of space-based images for Kilauea.
http://earthobservatory.nasa.gov/Search/index.php?hq=&q=kilauea+plume&sa=search