TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3112 SUBJECT: RXTE Observations of GRB050318 DATE: 05/03/18 23:07:23 GMT FROM: Craig Markwardt at NASA/GSFC/UMD C. B. Markwardt (GSFC/UMD), P. Boyd (GSFC/UMBC), N. Gehrels (GSFC) K. Hurley (UCB), F. E. Marshall (GSFC), M. Still (GSFC/USRA) RXTE observed GRB 050318 starting at 17:47 UTC (123 minutes after the BAT trigger), at the BAT reported position (Krimm et al, GCN Circ #3111). The exposure was 768 seconds. The RXTE PCA is a non-imaging instrument with a field of view of approximately 1 degree (FWHM). A PCA flux of 7E-12 erg/s/cm^2 was detected (2-10 keV), which is about four times the expected fluctuations due to the cosmic X-ray background. The flux is primarily below 6 keV. No obvious temporal variations are detected.