Table of contents
Table with the current status of the EVN stations for the continuous calibration (band dependent)
Current status of the continuous calibration implementation at the stations
| L Band | C band | M band | X band | K band | Q band | Last updated | |
| Ar | |||||||
| Bd | |||||||
| Ef | Available | Available | Available | Available | Available | Available | 18-06-2015 |
| Hh | Not yet | Not yet | Not yet | Not yet Under test on 15m antenna | Not yet | N/A | 14-09-2016 |
| Jb | 80 Hz | 80 Hz | 80 Hz | - | Awaiting testing | - | 01-02-2019 |
| KVN | - | - | - | - | No | No | 10-06-2015 |
| Mc | n/a | Available | Available | n/a | Available | - | 26-04-2017 |
| Mh | - | - | - | No | Tested in lab | No | 09-06-2015 |
| Nt | n/a | Available | Available | Not yet | Available | n/a | 16-10-2018 |
| On | Available | Available | Available | Available | No | No | 11-07-2018 |
| Ro | Available 10Hz | N/A | N/A | Available 10Hz | Not yet | Not yet | 3-10-2017 |
| Sr | Not yet | Not yet | Not yet | 21-10-2016 | |||
| T6 | |||||||
| Tr | |||||||
| Sh | |||||||
| Sv | |||||||
| Ur | |||||||
| Wb | not going to implement on current Receiver because too much effort | 29-01-2019 | |||||
| Ys | - | 80 Hz | 80 Hz | 80 Hz | not tested | No | 5-06-2015 |
| Zc |
- The DBBC allows to detect synchronously an 80 Hz signal integrating the power from the cal off and cal on phases.
- The 80 Hz signal can be obtained from output "Cont Cal".
- Continuous cal can be enabled by typing:
- cont_cal=on (at the FS)
- In some cases the signal is inverted and you can get negative Tsys. This is a pending issue to be solved. It can be solved by patching the FS, but this solution should be avoided in the future and look for a cleaner one. The DBBC allows to invert the signal but this does not work at V105 version yet.
- The file of station.prc should be ready to switch between continuous calibration for some bands and traditional calibration for others. How to properly set it? See the document of /usr2/fs/misc/dbbc.txt
- Note that your noise source should have a Tcal on the level of ~1 K rather than ~10 K.
- Onsala -- we have just tested the latest firmvare DDC V105 (version on 2015 Jun 10) which allows to swap the total power sampling between the Cal-On and Cal-Off registers. Now, our FS can do the proper measurements of Tsys, On-off, and Fivept at Onsala. The system is functional now. We have switched it on during N15L3. We are going to reduce Tcal from ~10 K to ~1 K and then start to use it in the user experiments at L and C bands in session 1/2016. The X-band 80Hz calibration hardware is also ready now and will be installed when the manpower is available.
- Hart -- we are working on implementing this on our 15m first as a test bed to see how well our solution will work. At the moment we are still waitin gon components for that.
