The Admiral

Good stuff! Thanks. Ian

From my primitive investigations explaining the traces does seem to be quite involved. There are a number of documents which I have referred to along the way, which you might find interesting. I'll list them at the end. I'm sure that you've heard this before, but the Graves transmitter beams in a Southerly direction from it location near Dijon at an altitude of between ~15° and ~40°. If the meteors detected are at around 100km high then this will give a distance of between 120km and 325km to its South, assuming simple line of sight. Something like this: On a map, this looks something like: The transmitter doesn't broadcast to the whole of the zone simultaneously, but switches cyclically between zones of azimuth. However, there has been some recent discussion on here about how it is possible for those in Scotland, for example, to be able to receive scatter traces even though they are beyond line of sight. As a result there has been some speculation that the antenna may also produce a 'backfire' beam which scatters off meteors nearer to home. The reflected frequency is Doppler shifted as a result of the moving meteor (head echo) and the ionized tail left behind. If my understanding is correct the meteor itself doesn't really slow down, but loses energy through ablation. So although it is easy to think of the Doppler shift is as a result of slowing down, as I originally did, but it is more complicated than that. Have a look at the following documents, which I hope will be of some interest, if you haven't already that is . Ian Detection_of_meteors_by_RADAR.pdf Graves-Echo-english.pdf Detecting Orbiting Objects.pdf Meteor Detection using SDR.pdf Radar Echoes from Space DK5EC.pdf Radio Doppler fromForward-Scatter Head Echoes.pdf

Indeed, but not sure it's funny . Here's my place in Oxfordshire. It's been murky all day, and we've had quite a bit of fog of late too. Mind you, I can check three different forecast sites and they all predict something a bit different, and more often than not, bearing no relation to my actual conditions! As my garden faces South with little to the North, I'm a but stumped. You could take photos of the Moon of course . Ian

I'd be very proud if that was mine! Stunning. Ian

It's a long while since I used mine, but I don't recall it losing location info. The problem with an in-built clock is that it might not be accurate enough and you'd need to keep resetting it. Without the GPS module I used to use https://time.is/ and use that to give me the accurate time. I've got the impression that accurate timing is important if you want accurate alignment. Ian

A little. I bought mine at the beginning of summer so it hasn't been out much so far. The kit for guiding has just been delivered, so that'll be the next step when the weather obliges and I have some time (and I'll report on it then). Meanwhile, this may be of some help:- Generally impressed with it's quality, I'm sure that you'll enjoy using it. Ian

Oh Göran, please stop doing this! . Yet another lovely image you've produced there, it's frustrating to know that I'll never get anything that good! Seriously though, they are a joy to behold. There's something about images which reveal dark nebulæ in all their glory. Ian

Could it have got any better? Yes, clearly it can! I like the result too . Ian

That RASA is certainly delivering Göran, when in capable hands of course . The revealed striations in the dust are incredible. I wonder if such depth of detail could ever be revealed in less than dark skies? Ian

Groan! I'd rather not think about what is happening to this country. My blood pressure is raised enough already 😭. Ian

One can only dream! Ian

Absolutely stunning! There's no doubt that photon count is king (so long as they're not from light pollution of course ) Ian

Thanks for the clarification and the added information. I'm not a planetry imager but I'd be very pleased to get something like your latest image. I guess the quality of seeing is going to be critical in determining final image quality, lucky imaging or not. Ian

I can't offer any thoughts on whether it's possible to get a better image, but it's pretty good to my eye. I'm a little confused though, there are two images, one showing apparently more detail than the other. What is the difference in processing? It would be nice to know for each how many subs you gathered, what percentage of those that you stacked, and what you used to process? Ian

Well that would explain what I was getting too, even having set 'cordwrap' to off. Why on earth would it do that, other than bad programming? Mind you, I've now got rid of StarSense as I'm using an iOptron mount. Ian

Sumptuous image. A wall-hanger for sure! Ian

I have no experience of doing this, but just a thought, if you use a much larger target like the Moon, you might be able to get a feel as to what the issue is, i.e. are you not achieving focus and/or whether your object centring is awry? Ian

Ermm, sorry, my mistake, 1/4" UNC is nearest to M6 not M4. Ignore that post then. Ah, I see you already have ☺ Ian

¼" UNC is a very close match for M4, but the threads are slightly different, enough for binding to take place after a few turns. You can get them on eBay in small quantities for little money, so it'd be worth a punt just to see. Try here. Ian

Personally there is no way I would expect to fettle to such an extent, on a 'scope costing nearly 2 grand, whether I liked DIY or not! It would have been returned, end of. What else can compel the manufacturer to up its game? Each to their own I suppose, and I if you end up with something approaching the optical quality of the Tak, and its ruggedness, then it may be money well spent. Somehow, purse and sows ear come to mind I admire your tenacity though! Ian

I only have access to my tablet, so I can't check it out, but I think the free ShotCut video editor might be able to do it. From what little I've read, the strain wave kit doesn't respond well to guiding, so it would be worth hearing any thoughts. Ian

Ah, then will you be writing up a review of the RT-135? ☺ Ian

May be this is a stupid question for those that run this sort of kit, but what happened to the flattener? It is plainly visible in the first photo, but then vanishes from sight . Ian

I had thought about the Tri-Pier when I acquired my GEM45, but ultimately decided that the extra weight might be a stumbling block, and went for the standard tripod with mini-pier on top. Actually, I would recommend the mini-pier anyway because having to set up and take down each session, I didn't think the threads in the tripod top plate would be long lived. The mini-pier's threaded holes appear to have an insert and hopefully more robust. I haven't enough experience with the mount to know if the tripod isn't up to snuff, but I've not had any problem. If it helps my initial review of the GEM45 is here: Overall, I'm pleased with the quality. Ian

Hi Dave, welcome to the fray! This was posted a while ago and might provide some useful input. At the beginning of lock-down I purchased the iOptron GEM45 (non-EC). Given that we've since gone through short nights and none too obliging weather it really hasn't been put through its paces, but it does seem a quality piece of kit. The latest generation of iOptron mounts do give a good payload for their weights, and was one of the reasons I opted for one as my ability to lift is a bit limited. Ian