Guest EI2KK Posted July 29, 2016 Share Posted July 29, 2016 Since last Wednesday data to NOAA is provided from DSCOVR instead of ACE but some files still contain ACE data.. There is difference between json file (looks like it is DSCOVR) http://services.swpc.noaa.gov/products/solar-wind/mag-5-minute.json and text file http://services.swpc.noaa.gov/text/ace-swepam.txt For the speed difference today was about 20km/s but for density looks like json file shows two times more p+/cm^3 than txt file.. Anyone knows where is such huge difference from? Is DSCOVR not calibrated yet? or mayby ACE data acuracy is questionable? I did some math and it looks like Solar Wind dynamic pressure showed on some NOAA's charts are calculated using ACE values from txt file.. Hori Link to comment Share on other sites More sharing options...
Marcel de Bont Posted July 30, 2016 Share Posted July 30, 2016 If my memory serves me correctly, there were been long standing issues with ACE's SWEPAM instrument. Not sure what the cause was but might be a combination of it just being old or if it was somehow damaged. I remember reading about it but don't exactly remember the details. Anyway, there used to be a time that especially the density readings were really bad, always being close to zero. They somehow fixed that but the density readings were never really optimal I think. I am sure DSCOVR is calibrated and ready to take over ACE's duty. The almost 1,5 year between launch and now was used to fine tune all the instruments so they wouldn't have switched if they weren't done. I trust the readings from DSCOVR more than I do from ACE to be honest. The data seems much steadier as well without any glitches like ACE had with insane density spikes sometimes. Remember also that while the two of them are at L1, they are in an orbit around the L1 point so they do not occupy the exact same patch of space and will also therefor not have exactly the same readings. Link to comment Share on other sites More sharing options...
Guest EI2KK Posted July 30, 2016 Share Posted July 30, 2016 Thanks for explanation Marcel.. Yes, I know both are orbiting around L1.. but for a few days density from ACE was about half of value from DSCOVR.. I wonder what abut all forecast algorythms used by NOAA if they are based on data having 50% accuracy... I hope DSCOVR is OK.. Link to comment Share on other sites More sharing options...
Vancanneyt Sander Posted July 31, 2016 Share Posted July 31, 2016 The density data from ACE wasn't that reliable in the past, density below 20 was always pretty inaccurate at ACE. Also a bit due to the age of ACE cuz i remember back in the previous cycle it was more accurate then the last 5 years. That would explain the better readings from DSCVR Link to comment Share on other sites More sharing options...
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