Welcome to the DIVMAP video tutorial.

After you have successfully installed Oracle VM VirtualBox and loaded Ubuntu image with

the DIVMAP software, you can log in to the operating system with the user student and

the password DIVMAP.

After you have launched the system successfully, you see the folder student on the desktop,

which you can open and you will see two important folders there.

One is the DIVMAP folder.

There is the DIVMAP starting package with the cookbook and the help function.

These are PDFs and you can look into those for further information.

Please don't delete the DIVMAP.boot file.

This one is important for different functions within the DIVMAP software.

Your data that you will be working on is located in the folder vlbi-data and there you will

have different folders which will be necessary for completing the course.

Having a look at those, you see that there are UVF files located.

These are UVFITS files.

You can load those files into DIVMAP and start working on them.

To run DIVMAP, you open a terminal which you see on the left side.

Once this is open, you can type with the command ls the contents of your folder that you are

operating in right now.

There you already see the vlbi-data folder being in there.

You can type cd for change directory vlbi-data or you can also type cd vl and then press

the tab key on your keyboard and it will autofill in case there is only one folder or file in

the current folder with this beginning signature.

Confirm and then you are inside the folder vlbi-data.

There you can ls again to see the contents.

We want to have a look at the data of 0420 plus 022.

So cd 04 tab return ls and there you see the UVFITS file.

From here you start DIVMAP by just typing DIVMAP confirm.

It will open two new windows, a small one which you can ignore which is on the top here.

The bigger one you can push to the side so it will be autofilled for the right half side

of the screen and the terminal that you were typing in before you can push to the left

hand side so it will autofill the left hand side.

These two windows we will be needing for running DIVMAP.

To read in the data you have to write OBSRF or short OBS and then the name of the file

that you want to read in.

Since there is only one file in the folder we can just hit tab.

You see the file that we just saw in the file explorer.

So you can now type 0 and tab and it will autofill the file name for you.

Confirm with return and then the data is loaded into the RAM so you can start working on it

now.

But first you need to select which stocks parameter you want to take.

We are working with the total intensity so you type select i confirm and it will load

the total intensity of your whole data set.

After that we need to define the weighting for the data set.

We want to pick natural weighting which is uvw 0 and minus 1.

Confirm and then we have natural weighting selected for our data.

Next we want to define our map size that we do with the command maps and I will type in

1024 pixels.

You need to choose always the size in power of 2 so you cannot use map size 1000.

If you just confirm then DIPMAP will choose your pixel size as it thinks it is best based