# Obslist

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This page documents the obslist function of Python module analysisUtils.

In CASA, task listobs tells you the antenna positions in Longitude and Latitude. Sometimes it's informative to know the positions in a local offset coordinate system, and what the min/max baseline lengths are. This function parses the telescope name from the OBSERVATION table, then finds the coordinates of the center of the array (COFA), then converts each station coordinates into local offsets in meters from the COFA and prints the information. See also plotconfig.

## Examples

```# In CASA
au.obslist('Band7multi_april22.ms')
```
```Antenna 0 = DV04 on pad J505, lat/long offset (m) = -7.2138/ -488.2036 Antenna 1 = DV06 on pad T704, lat/long offset (m) = +42.8973/ -465.4952 Antenna 2 = DV07 on pad J510, lat/long offset (m) = -0.3652/ -512.3043 Antenna 3 = DV08 on pad T703, lat/long offset (m) = +42.8783/ -525.0569 Antenna 4 = DV09 on pad N602, lat/long offset (m) = +8.8009/ -473.7260 Antenna 5 = DV10 on pad N606, lat/long offset (m) = +19.1975/ -515.2704 Antenna 6 = PM01 on pad T702, lat/long offset (m) = -23.6261/ -532.1683 Antenna 7 = PM02 on pad T701, lat/long offset (m) = -29.1258/ -468.2863 Antenna 8 = PM03 on pad J504, lat/long offset (m) = +22.2007/ -497.7628 Longest baseline = 91.018 m = DV06-PM01 Shortest baseline = 16.586 m = DV10-PM03 ```

In some cases it may be useful to use one Antenna's position as a reference rather than the center of the array stored in casa. To do this, simply specify the antenna ID or its name:

```# In CASA
au.obslist('Band7multi_april22.ms',cofa=8)
```
```Antenna 0 = DV04 on pad J505, lat/long offset (m) = -29.4146/ +9.5595 Antenna 1 = DV06 on pad T704, lat/long offset (m) = +20.6965/ +32.2686 Antenna 2 = DV07 on pad J510, lat/long offset (m) = -22.5659/ -14.5420 Antenna 3 = DV08 on pad T703, lat/long offset (m) = +20.6775/ -27.2949 Antenna 4 = DV09 on pad N602, lat/long offset (m) = -13.3998/ +24.0375 Antenna 5 = DV10 on pad N606, lat/long offset (m) = -3.0033/ -17.5081 Antenna 6 = PM01 on pad T702, lat/long offset (m) = -45.8268/ -34.4065 Antenna 7 = PM02 on pad T701, lat/long offset (m) = -51.3266/ +29.4773 Antenna 8 = PM03 on pad J504, lat/long offset (m) = +0.0000/ +0.0000 Longest baseline = 91.018 m = DV06-PM01 Shortest baseline = 16.586 m = DV10-PM03 ```
```# In CASA
au.obslist('Band7multi_april22.ms',cofa='DV06')
```
```Antenna DV06 has ID 1 Antenna 0 = DV04 on pad J505, lat/long offset (m) = -50.1111/ -22.7091 Antenna 1 = DV06 on pad T704, lat/long offset (m) = +0.0000/ +0.0000 Antenna 2 = DV07 on pad J510, lat/long offset (m) = -43.2624/ -46.8105 Antenna 3 = DV08 on pad T703, lat/long offset (m) = -0.0189/ -59.5634 Antenna 4 = DV09 on pad N602, lat/long offset (m) = -34.0964/ -8.2312 Antenna 5 = DV10 on pad N606, lat/long offset (m) = -23.6997/ -49.7767 Antenna 6 = PM01 on pad T702, lat/long offset (m) = -66.5232/ -66.6751 Antenna 7 = PM02 on pad T701, lat/long offset (m) = -72.0231/ -2.7914 Antenna 8 = PM03 on pad J504, lat/long offset (m) = -20.6965/ -32.2686 Longest baseline = 91.018 m = DV06-PM01 Shortest baseline = 16.586 m = DV10-PM03 ```