High-Gain Antenna Test Continues

[SDO]

The SDO Team continues running the high-gain antenna (HGA) test. We are pretending that the “bottom” HGA has stopped working and we are running the spacecraft upside down to stay in contact with the ground. There has been no problem with the HGAs, but we need to keep the SDO Team thinking how to handle these problems before they happen.
As you can see in the picture, the FOT is using Camilla as a reminder what roll angle SDO is at. Currently at 153.7°, tomorrow SDO will roll to 180°. The test will end on April 25 at 1900 UTC (3 pm ET).
As the test progresses, the software to correct the orientation of the near-realtime images continues to be improved. By the end of the test all of the images will be correct!

More...

[ramus]

I guess i want to show my ignorance but what is this about, what does a mean, and what does it relate to, a little back ground would help ..................

[petra]

Me too. It's solar dynamics so it must be about the sun, that's about all I get. The part about all images being correct sounds exciting, and I'd be interested to know what's planned to do with the data

[Bob]

Posted by ramus (here)
I guess i want to show my ignorance but what is this about, what does a mean, and what does it relate to, a little back ground would help ..................

Starting with what SDO stands for:

The Solar Dynamics observatory1 (SDO) is expected to launch in the early part of 2009.
It will produce a near continuous record of changes on the Sun.

It communicates continuously using TWO high gain antennas to earth receiving stations.

The antennas are calibrated and tested periodically as are all the systems on-board the space-craft

The dish like projections shown in the vid are the high gain antennas

https://svs.gsfc.nasa.gov/vis/a01000...42/beauty1.mp4

Still shot



see: https://en.wikipedia.org/wiki/Solar_...cs_Observatory

These great images that you see on this page, at the top come out of SDO



NASA's pdf report is located HERE - https://ntrs.nasa.gov/archive/nasa/c...0180000032.pdf

It's done on satellites often, geosynchronous satellites for instance have to be properly repositioned due to drift. SDO needs periodic re-calibration, nothing mysterious. There is nothing wrong, normal maintenance is a recommended procedure.

HGA calibration consists of finding values for the misalignments and biases of the antenna pointing mechanism that will maximize the received antenna signal power. Errors in the knowledge of these parameters result in HGA pointing directions that differ from those commanded and therefore reduce the received power.

The only available measurement that can be used for this calibration is the radio frequency (RF) power measured by a receiver (usually reported as decibels of gain which is a logarithmic function of relative power). The basic method _used for HGA calibration involves
minimizing the differences between the measured and predicted power over observed HGA gimbal angles with respect to the calibration parameters.

The antennas are mounted on a movable gimbal, allowing for movement, or "pointing" with extreme precision.

[Nick Matkin]

I've no idea either, and I take often note of that site's posts. The photo (of an upside down plastic duck in a sweater?) kind of suggests something's wrong...

[petra]

Posted by Nick Matkin (here)
I've no idea either, and I take often note of that site's posts. The photo (of an upside down plastic duck in a sweater?) kind of suggests something's wrong...

I thought it was an antenna cover, the weird factor never even crossed my mind

[Bob]

Posted by petra (here)

Posted by Nick Matkin (here)
I've no idea either, and I take often note of that site's posts. The photo (of an upside down plastic duck in a sweater?) kind of suggests something's wrong...

I thought it was an antenna cover, the weird factor never even crossed my mind

the 'kids' at NASA have a sense of humor.. In the OP, the FOT (Flight Operations Team) says this image is to REMIND the staff of the orientation of the SDO.

the FOT is using Camilla as a reminder what roll angle SDO is at. Currently at 153.7°

Nothing is wrong. They just love their chickens, or ducks, or ducks in sweaters, or rubber-ducks... (rubber ducky is a slang for a bendable walkie-talkie antenna too btw)...

On this link: is their blogspot page referenced in the OP post 1
http://sdoisgo.blogspot.com/2018/04/...continues.html

Here's another reminder image:





jokes, ducks, chickens whatever. "sense of humor - there 'ain't' nuthin goin a-wrong' "

[dynamo]

I believe the OP is just an "RSS Feed" (integrated into the vBulletin software that runs this Forum) which automatically generates the thread/post.
So do not expect a reply from the original poster LOL.

[DeDukshyn]

Posted by dynamo (here)
I believe the OP is just an "RSS Feed" (integrated into the vBulletin software that runs this Forum) which automatically generates the thread/post.
So do not expect a reply from the original poster LOL.

Correct. And that is why you can't thank it.

[petra]

Posted by DeDukshyn (here)

Posted by dynamo (here)
I believe the OP is just an "RSS Feed" (integrated into the vBulletin software that runs this Forum) which automatically generates the thread/post.
So do not expect a reply from the original poster LOL.

Correct. And that is why you can't thank it.

Oh my goodness! I thought we were all people. My bad