Hi,
I got a photo of the KMS-4 sat and started wondering about the possible frequencies based on what could be antenna. I think this photo might shed some light on it. I don't want to say what I think they were thinking. Other than they could have been HAMS!
Here is the sat: https://drive.google.com/open?id=0Byq2L9ccyLZeYTVzNWdFS3NLSnM
Here is the nacelle in which it fit. https://drive.google.com/open?id=0Byq2L9ccyLZeZ2pQX1ZtcjlSTk0
There are some other gizmos on the sat. What do you guys think is going on here with the visible components and the other sat features?
FYI, I know this is somewhat off topic. But as a HAM and space lover, I don't know what better group to take a look at these things.
Thanks, Robb KB3RBA
I got a photo of the KMS-4 sat and started wondering about the possible frequencies based on what could be antenna.
I wrote an email to the amsat-bb a while ago which I will repeat below. You should note there has been no reported emissions, and the photos linked below may have been from a model made for the press, so may have had fake/non flight hardware. The photos are also from the previous launch a few years ago.
Where did you get the photos you linked to and when were they taken/broadcast?
---------------------------------------------------------------------------------------------- Not sure if it has been posted yet, but there is a good technical write up of previous North Korean satellites here:
http://38north.org/2012/09/nhansen091212/
Some sites suggest 450 to 470Mhz is likely band. Ideally would need a very high gain setup with a wideband SDR dongle to see any transmissions. If they wanted they could turn all transmitters off unless commanded or else only when the GPS says they are within range of the ground station. Note the article linked is only the older satellites.
I don't believe there was any public reception of actual emissions from previous models. It does look likely UHF will be used. In this day and age if it does emit on UHF constantly someone probably will detect it and share. with possibly 6 UHF antennas there may be multiple downlinks. I will buy a pint for whoever decodes the GPS location downlink first!
Got the photos off the air on 2/13 broadcast of Korea Central TV.
I noticed though it looked like it could be two 1/4 wave dipoles at 1/4 wave spacing.
Def. could be a fake/mockup.
On Mon, Feb 15, 2016 at 5:03 AM, Daniel Cussen dan@post.com wrote:
I got a photo of the KMS-4 sat and started wondering about the possible frequencies based on what could be antenna.
I wrote an email to the amsat-bb a while ago which I will repeat below. You should note there has been no reported emissions, and the photos linked below may have been from a model made for the press, so may have had fake/non flight hardware. The photos are also from the previous launch a few years ago.
Where did you get the photos you linked to and when were they taken/broadcast?
Not sure if it has been posted yet, but there is a good technical write up of previous North Korean satellites here:
http://38north.org/2012/09/nhansen091212/
Some sites suggest 450 to 470Mhz is likely band. Ideally would need a very high gain setup with a wideband SDR dongle to see any transmissions. If they wanted they could turn all transmitters off unless commanded or else only when the GPS says they are within range of the ground station. Note the article linked is only the older satellites.
I don't believe there was any public reception of actual emissions from previous models. It does look likely UHF will be used. In this day and age if it does emit on UHF constantly someone probably will detect it and share. with possibly 6 UHF antennas there may be multiple downlinks. I will buy a pint for whoever decodes the GPS location downlink first! _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (2)
-
Daniel Cussen -
Robb Hill