Last Update: 22th November 2017

Changes in ... | General Changes | Obstable | Source Table | Reference Table | Scan Table | Device Table |

the nobs: what have changed from the zobs?

This page shows a summary of differences between the nobs and the zobs. This information would be useful for familiar users of the Nobeyama 45-m telescope. Please note that some issues will be changed in future developments of the nobs.

General Changes

Refrence Table Information of reference positions can be specified in the Reference table, which is newly added to the nobs.
Extensions of the tables
Extensions of the tables are changed as follows;
zobs: *.observe, *.source, *.scan, *.device
nobs: *.nobserve, *.nsource, *.nreference, *.nscan, *.ndevice, *.ndebug
*.ndebug is automatically generated in the open-use version of nobs.
Character Limit
*nobserve has 7 character limit (no change from the zobs), while other tables have 16 character limit.
Available Characters for a Filename
A filename must start with a-z, and subsequent characters should be a-z, 0-9, _, and -.
Capital characters are not accepted.

Obstable (Project tab)

Project Name
In the zobs, a project name is required when starting-up the software.
On the other hand, the project name can be specified and changed in the Project tab.

Source Table (Source Tab)

Velocity Frame
The 'Heliocentric' option in Velocity Frame is removed.
Source Type
'Solar Object', which is for specifing solar system objects, is removed.
Coordinate System
The coordinate system must be shared in that in the Reference table.
Region Name (optional)
New parameter:
If needed, you can specify the region name of the target source as you like.
The character limit is 16.

Reference Table (Reference Tab)

Number of Reference Position
You can set up to 9 reference positions in this table.
Relationship to the Scan Table
In 'Sequence Pattern' in the scan table (for Single Point, OTF, and Multi Point scan), you can specify the reference positions with their IDs, 1-9, in the Reference table.
Blank Sky
For the On-On scan mode, ID (1) in the refrence table is used as the blank sky.
Coordinate System
The coordinate system must be shared in that in the Source table.

Scan Table (Scan Tab)

Relationship to the Reference Table
In 'Sequence Pattern' in the Scan table (for Single Point, OTF, and Multi Point scan), you can specify the reference positions with their IDs, 1-9, in the Reference table.
Definition of the Rotation Angle
The beam rotation angle of the receiver stage is specified in the device table in the zobs, while in nobs it is moved to the scan table. You should note that the definition of the beam rotation angle is different between the zobs and the nobs as summarized in figure below:
Definition of Position Angle
In the zobs the zero point of the beam rotation angle and the scan position angle are common, whereas the beam rotation angle in the nobs is defined as an offset angle from the scan position angle. In other words, [Beam rotation angle in the zobs] = [Beam rotation angle in the nobs] + [Positon angle].

Single Point

Coordinate System
'Coordinate system' is removed.
Sequence Pattern
New parameters::
In the nobs, multiple reference positions can be specified.


Receiver and Beams
The 'On-On' observations can be performed with the Beam 1 and Beam 3 of FOREST. The beam separation is ~71''.

On-The-Fly (OTF)

Concept of 'Block'
'Block' is introduced. The concept of 'Block' is illustrated in the figure below:
conceptual diagram of On-The-Fly
New parameters:
Number of Blocks, block spacing, Block Begin, Block End.
These new parameters are fixed in the 2017-2018 observing season.
Number of Scan
New parameters:
The total number of the scan rows.
Dump Time
It is moved from the device table to the scan table.
In the open-use program it is fixed to 0.1.

Cross Point

Cross Point
This is called “Pointing” in the zobs.
Sequence Pattern
In 'Sequence Pattern', on-positions are specified using 0-9 in the zobs, while alphabet, a-z, is used in the nobs.
Position Angle
The parameters are the same as in zobs, but the position angle is removed.

Multi Point

Multi Point
This is called 'Random' in the zobs.
Definition of Calibration Sequence
The definition of 'Calibration interval' is changed.
In the nobs, it is counted in the number of the observation sequence.

Device Table

Spectral Window Mode
The Spectral Window (SpW) mode is implemented, and the number of the arrays in the Backend tab is increased from 16 to 32 (A17-A32 are for the SpW mode).
Receiver Names
The names of the following receivers are changed.
H20ch1 -> H22R, H20ch2 -> H22L, TMULT -> FOREST.
Parameter Names
The names of the following parameters are changed.
Rx -> Frontend (FE), SB -> IF, Center Freq -> Rest Freq., LO2 Freq. -> LO(DC) Freq.
IF Names
The names of the IFs (sidebands) are changed as follows:
New Parameters
New parameters:
Comments (in the Frontend tab): Free space with the maximum number of characters of 100.
SpW mode: Disalbe/Enable (in the Backend tab)
The checkboxes next to the arrays (in the Backend tab): You have to check the boxes of the arrays which you use in the observation. Be aware that the arrays without checks will not observed.
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