WAPP Specifications (as on: 2/27/2003)

for 1 quadrant, i.e. a board with 16K correlators

• Bandwidth
• 195kHz to 100MHz in octave steps
• Lags (Spectral Line)
• 195kHz to 50MHz BW
• 1 channel, 3-level auto, 16384 lags
• 2 channel, 3-level auto, 8192 lags/chan
• 1 channel, 9-level auto, 4096 lags
• 2 channel, 9-level auto, 2048 lags/chan
• 3-level Stokes, 4096 lags/product
• 9-level Stokes, 1024 lags/product
• 100MHz BW
• 1 channel, 3-level auto, 8192 lags
• 2 channel, 3-level auto, 4096 lags/chan
• 1 channel, 9-level auto, 2048 lags
• 3-level Stokes, 2048 lags/product

   Max. no of lags per output product (or channel) =

                       16*1024
    ------------------------------------------------------
    {log_3(N_level)}^2 * N_interleave * N_output_products]

   N_level is 3 or 9 [i.e. log_3(N_level) is 1 or 2 respectively];
   N_interleave is 1 (for BW <= 50 MHz) or 2 for 100 MHz BW;
   N_output_products is 1 or 2 (channel autocorrs) or 4 (Stokes);
   & log_3() indicates log to the base 3.

• Pulsar Modes
• 50MBytes/s max for correlator board
• >50MBytes/s max for EDT/computer
• 38MByte/s max data rate to disk

The best resolution for a 100MHz bands, using 16 bits/lag, and summing the polarizations are given by the formulas,

     #lags = (i - 1)* 6.25,  where i = integration time in usecs
     Data rate to disk = 12MBytes/s;  Resolution = 100MHz/#lags

Integration time	Max lags	Resolution
100us	616	162kHz
64us	392	255kHz
32us	192	520kHz



• Direct Sampling

2 channels,continuous sampling

Bandwidth(MHz)	Data Rate Mbyte/s	Bit Packing
50	25	1
25	25	2
12.5	25	4
6.25	12.5	4
3.125	6.25	4
1.56	3.12	4
0.78	1.56	4
0.390	0.78	4
0.195	0.39	4