Header Format

The image header may be displayed using command HEADER . This command produces a screen with the following aspect (except for the numbers in the last two columns which are added here for reference purpose):

File :         /users/me/work.lmv                                              1
Size        Reference Pixel           Value                  Increment          
    51 -0.5000000000000000      -21.00000000000000       1.000000000000000     2
    53 -0.5000000000000000      -25.00000000000000       1.000000000000000     2
   113   57.50000000000000      -15.60490417480469       1.300384521484375     2
     1  0.0000000000000000E+00  0.0000000000000000E+00  0.0000000000000000E+00 2
Blanking value and tolerance      -1000.0000      0.10000000                   3

Source name         VHYA                                                       4
Map unit            K                                                          5
Axis type           RA           DEC          VELOCITY                         6
Coordinate system   EQUATORIAL                                                 7
Right Ascension     10:49:11.300        Declination        -20:59:05.00        8
Lii       -91.03457538867391            Bii       33.60127769133289            9
Epoch              1950.0000                                                  10
Projection type     RADIO               Angle    0.0000000000000000E+00       11
Axis 1     A0       10:49:11.300        Axis 2     D0      -20:59:05.00       12
Minimum                                                                       13
Maximum                                                                         
Axis 3 Line Name    12CO(2-1)           Rest Frequency   230537.9900000000    14
Resolution in Velocity    1.3004038     in Frequency    -1.000000000000000    15
Offset in Velocity       -15.600000     Image Frequency  0.0                  16

The lines contain:

1.

Image filename

2.

Number of pixels, reference pixel, value, increment for each axis

3.

Blanking value and tolerance

4.

Source name for bookkeeping

5.

Units of map

6.

Type of each axis

7.

Type of coordinate system

8.

Source coordinates in Equatorial coordinate system

9.

Source coordinates in Galactic coordinate system

10.

Epoch of equatorial system

11.

Type of projection, and angle of the projection axis with respect to north

12.

Projected axis numbers, and coordinates of projection center

13.

Value and pixel coordinates for the minima and maxima of the image.

14.

Frequency axis number, Line name (for bookkeeping) and frequency of the reference pixel.

15.

Velocity and frequency resolution

16.

Velocity and image frequency of the reference pixel.

Each item can be modified, except the numbers of pixels of course.