MWA Frequency Specifications

The MWA has a very flexible signal path that allows various frequency settings to suit your science. The MWA has 24 coarse frequency channels that each have a bandwidth of 1.28Mhz and can be arranged anywhere between 80 and 300 MHz. Each frequency channel ID has a centre frequency of 1.28xID MHz. For example, channel ID 100 has a centre frequency of 128 MHz. The frequency channels don’t have to be contiguous, so we have a flexible “freqspec” how you wish to arrange the frequency channels

Each freqspec is can be described as either:

<channel>
<center>,<width>,<increment>
<start>:<stop>:<increment>

where the increments default to 1. Multiple entries can be given separated by a ;

Example 1: A Contiguous Channel

You want to observe with 24 contiguous frequency channels, centered on channel 121 (155 MHz):

121,24

Example 2: Picket Fence

You want to spread out the 24 channels, with gaps of 2 channels in between each, centered on 121:

121,24,3

which is the equivalent to:

109;112;115;118;121;124;127;130;131;132;133;134;135;136;137;138;139;140;141;142;143;144;145;146

Example 3: Two bands

You want to two wide frequency bands so you choose channels 101-112 inclusive, and channels 141-152 inclusive:

101:112;141:152

Example 4: 12 Pairs of Contiguous Channels

You want 12 frequency bands, each of which are two channels wide:

62;63;69;70;76;77;84;85;93;94;103;104;113;114;125;126;139;140;153;154;169;170;187;188