The ftp transfer rate in 2001 was an average of 6.2 GB per day (188 GB per
month) compared to 5.0 GB per day in 2000, 3.8 GB per day in 1999,
2.3 GB per day in 1998 and 0.7 GB per day in 1997.
The data transferred is predominantly RXTE (54%), with other missions of note
being ASCA (7.2%), ROSAT (3.4%), XMM-Newton (2.4%), CGRO (1.7%), and
BeppoSAX (1.5%). Significant data transfers are also made from the non-mission
directories Software (11%) and Retrieve (16%).
In terms of data attractiveness DA (defined for each mission as the amount of data
ftped in a year divided by the archive size), RXTE is the most popular mission (DA = 121%)
followed by XMM-Newton (81%), BeppoSAX (54%), ROSAT (45%), and ASCA (25%).
The http transfer rate of Web pages, images, etc., in 2001 was 3.9 GB per day
119 GB per month), compared to 3.0 GB per day (90 GB per month) in 2000 and
1.7 GB per day (50 GB per month) in 1999. The http rate in 2001 was
thus ~ 63% of the ftp rate, and by the first quarter of 2002 exceeded the ftp rate.
Transfers from the HEASARC's main E&PO areas `Imagine the Universe' and
`StarChild' (the latter maintained by Laura Whitlock at Cal State Sunoma) remained very
high: by early 2002 they were getting >4 million & >1 million hits per month, respectively.
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