Guest Observer Facilities & Science Centers Select One AGILE ASCA BeppoSAX COBE CGRO Chandra EUVE Fermi (formerly GLAST) GALEX HETE-2 INTEGRAL ROSAT RXTE Suzaku Swift WMAP XMM-Newton NASA Archives Select One ADS AstroGravS EOSDIS HORIZONS IRSA LAMBDA MAST NExScI (formerly Michelson) NED NSSDC NStED PDS SDAC SPDF Spitzer Science Center HEASARC Tip: View all tips HEASARC Usage Statistics The HEASARC periodically makes its usage statistics available for the HEASARC Users Group and other interested parties. Archive size and data downloads over time (1993-2007 & projected thru 2010) Growth of the HEASARC Archive (1996-2008) Demand for HEASARC Web services (1993- 2007) Citations of selected HEASARC missions (1993-2007) Data requests by quarter (1998-2008) Data transfer rates by TB and by equivalent numbers of datasets, broken down by mission (1998-2007) History of Data Transfers by Mission (1993-2007) Data Holdings over time and by mission (1998-2007) Detailed HEASARC Usage Statistics (Internal Access only) Click on any figure below to see an enlarged, printable version. Archive Size and Data Downloads over Time Figure 1: HEASARC archive size & annual data download amounts over time. Back to top Growth of the Archive Figure 2: Past (1996-2008) growth of the size of the HEASARC science data archive. Back to top Demand for HEASARC Web Services Figure 3: Demand for HEASARC Web Services: Annual numbers of SkyView images requested, Browse queries submitted, and volume of science web pages downloaded from 1993-2007. Back to top Citations of Selected HEASARC Missions Figure 4: Number of citations of selected HEASARC missions over time. Back to top Science data and web pages requested Figure 5: FTP and HTTP requested volume of data and web pages (TB per quarter). Back to top Transfer rates Figure 6(a): The amount of TB of data downloaded in 2007, broken down by mission. A grand total of 28.88 TB of HEASARC data was copied by our users in 2007. Figure 6(b): The number of (equivalent) datasets downloaded in 2007, broken down by mission. A grand total of 64,351 HEASARC datasets was copied by our users in 2007. Back to top The number of datasets transferred in 2005 by mission/directory. The number of datasets transferred in 2004 by mission/directory. The number of gigabytes transferred in 2003 by mission/directory (top) and datasets transferred in 2003 by mission (bottom). The number of gigabytes transferred in all of 2001 by mission/directory. The number of gigabytes transferred in all of 2000 by mission/directory. The number of gigabytes transferred in all of 1998 by mission/directory. Back to top History of Data Transfers by Mission Figure 7: History of data transfers for major missions, in terms of annual data downloads (Terabytes per year). Back to top Data Holdings Figure 8: HEASARC data holdings as of October 2007, broken down by mission. These totalled 16.4 TB, which is more double the 7.6 TB size of the archive in October 2005. Back to top HEASARC data holdings as of October 2005, broken down by mission.These totalled 7.57 TB. HEASARC data holdings as of November 2003, broken down by mission.These totalled 3.219 TB. HEASARC data holdings as of November 2001, broken down by mission. These totalled 2.430 TB. HEASARC data holdings as of December 2000, broken down by mission. These totalled 2.217 TB. HEASARC data holdings as of December 1999, broken down by mission. These totalled 1.663 TB. HEASARC data holdings as of January 1999, broken down by mission. These totalled 1.373 TB. HEASARC data holdings as of March 11, 1998, broken down by mission. These totalled 0.955 TB. Back to top HEASARC Home | Observatories | Archive | Calibration | Software | Tools | Students/Teachers/Public Last modified: Friday, 23-May-2008 09:14:20 EDT