Ground based weather radar at its best

I have merged many ADL/Golze related threads into one – here

Sebastian_G wrote:

Radar composites are compositions of dozens and in some case over hundred radar stations operated in different countries. All their data must be measured which can take several minutes if multiple sweeps at different angles are done.

I see your point regarding composite radar images. But the thing is that most single radar images (of 1 station), still only offer a 10 minute refresh rate. I think that’s just down to archaic systems.

JasonC wrote:

No, there is a vast amount of processing that takes place on the data before it is distributed. It is not a sweep of a single radar, it is typically a composite picture of several including different slant angles. Processing is used to make it a fair view of the space covered. Your 512×512 png is derived from a very large complex data set.

So am I to assume that the radar is sweeping continually for 10 minutes at all sorts of different angles and frequencies to generate one image each time? My aircraft radar completes a single sweep of a third of the sky in a few seconds covering up to 100nm+, with an altitude band of probably around 100,000 feet at that point. Granted the accuracy and sensitivity isn’t quite there, but we’re talking about an small airborne radar. Surely the professionals with their massive white domes can do much better, much quicker…?

There are various radar sites around Europe and if you want to put in some time into writing some code you could collect the pixels and re-map them onto a European map. I reckon that’s what this .cz site (which has come up before e.g. here) does. In fact that site came up even earlier – here and the data source is suggested there

If such a feed could be georeferenced it would be quite useful. This is what ADL do but they get the real digital data AFAIK, not images which need joining up and remapping.

Robin_253 wrote:

Up to date radar data and no adds, not even a single banner

Up to date not quite. Checking right now (0820z) the last available pic is 0800z.

Apart, I wonder what their sources are. The pic I saw at 0800z does not fully correspond with other coverage I have.

Who is then sponsoring this site: http://www.radareu.cz ?
Up to date radar data and no adds, not even a single banner

Radar data is sold commercially, and they sell different feeds at different prices. Just like stock market prices. The European consortium charged with merging and marketing it used to be called Opera; not sure what the current one is. It was a monopoly created by European wx offices, to exploit their “property” commercially.

You can get 15 min radar for free from meteox.com (well, funded by adverts so meteox pays something to get it, I guess). Any faster and you pay seriously more. 5 minute data is probably a few k a year and that is what most wx pay sites offer e.g. the avbrief.com radar subscription. Faster still would cost serious money – too expensive for GA in general.

I too don’t believe for a moment the processing (CPU time) is the bottleneck.

Archie wrote:

Sorry I’m confused here, how long does one radar sweep take?
Stating that it can’t be transmitted quicker is ridiculous. One radar snapshot can be transmitted as a 512×512 .PNG (<10Kb) over the internet which takes 7 milliseconds.
It’s probably due to the fairly antiquated proprietary systems that are used.

No, there is a vast amount of processing that takes place on the data before it is distributed. It is not a sweep of a single radar, it is typically a composite picture of several including different slant angles. Processing is used to make it a fair view of the space covered. Your 512×512 png is derived from a very large complex data set.

what_next wrote:

So yes, now I know for sure that ATC have an excellent weather radar and they can use it in the best possible way to steer light aircraft around ugly weather. If they only wish to do so.

But you wouldn’t assume they have it on your next flight, would you?

Sebastian_G wrote:

Average age of displayed radar data is the sum of:

A) Half of data acquisition interval (~2.5 min)
B) Data processing and transmission time (~4-12 min)
C) Half of data update interval (~2.5-7.5 min)

Sorry I’m confused here, how long does one radar sweep take?
Stating that it can’t be transmitted quicker is ridiculous. One radar snapshot can be transmitted as a 512×512 .PNG (<10Kb) over the internet which takes 7 milliseconds.
It’s probably due to the fairly antiquated proprietary systems that are used.
When satellite is used to transfer data for cockpit display, there is an obvious bottleneck in the price of bandwidth. but that is completely independent from the weather radar system. I.e. a lot of pilots I know fly around with wx radar overlays on their iPads/iPhones. That’s basically realtime data straight from wx bureau server. The fact that the data that the wx bureau server holds is not up-to-date has to do with the way it’s relayed from the radar to the server. There is no reason it could not be made real time these days,

Those who want to know what French ATC has at their disposal for weather information, some info here.

JasonC wrote:

Rich, I know it was scary but this concerned me greatly until I remembered not all aircraft are pressurised….

If my leg hadn’t been cold as well as wet I’d have thought the same thing!