Synopsis
makeim(scan, start, stop, step, imname, spwid, nx, ny, cellx, celly, gridfn)
Description
This command will construct a data cube (position-position-frequency) from
a mapping procedure. It uses the
imager tool to achieve this. The
user selects the starting scan of a mapping procedure and the channel range
over which to produce the cube (start, stop). An optional averaging is
offered through the step argument. The cell size can also be
optionally specified with the number and units; both cellx and celly
must be specified to over-ride the default calculated value (e.g.,
cellx='4arcmin',celly='4arcmin'). The default gridding function is the boxcar (BOX);
PB (primary beam) and SF (polate spheroidal) may also be specified.For
the BOX and SF gridding functions, the size of function can be specified
through the convsupport argument. The units of convsupport are pixels in
the resulting image and this specifies a radial size of the convolving
function. For BOX, a convsupport of 0 (the default)
corresponds to nearest cell gridding. A convsupport of 1 is boxcar of width 3
(-1, 0, and +1). For SF gridding, the default size is 1 a radius of 1 pixel.
Larger values may produce images with better noise characteristics at
the expense of a loss of spatial resolution. There is no gridding along
the frequency axis (data are mearly averaged into the nearest frequency channel
as they are gridded on to the image). The default value is chosen when
convsupport has a boolean or non-numeric value.
Arguments
scan |
|
scan number |
|
|
Allowed: |
integer |
|
|
Default: |
no default |
start |
|
starting channel |
|
|
Allowed: |
integer |
|
|
Default: |
no default |
stop |
|
stopping channel |
|
|
Allowed: |
integer |
|
|
Default: |
no default |
step |
|
number of channels to average over for final cube |
|
|
Allowed: |
integer |
|
|
Default: |
1 |
imname |
|
name of output image |
|
|
Allowed: |
string |
|
|
Default: |
scanimage |
spwid |
|
spectral window id number |
|
|
Allowed: |
integer |
|
|
Default: |
F |
nx |
|
number of cells in x |
|
|
Allowed: |
integer |
|
|
Default: |
F |
ny |
|
number of cells in y |
|
|
Allowed: |
integer |
|
|
Default: |
F |
cellx |
|
cell size in x |
|
|
Allowed: |
string |
|
|
Default: |
F |
celly |
|
cell size in y |
|
|
Allowed: |
string |
|
|
Default: |
F |
gridfn |
|
gridding function |
|
|
Allowed: |
'BOX', 'PB', or 'SF' |
|
|
Default: |
BOX |
Returns
T (if successful)