Recent

Author Topic: Problems with time and Distance Help Please  (Read 4270 times)

JLWest

  • Hero Member
  • *****
  • Posts: 845
Re: Problems with time and Distance Help Please
« Reply #75 on: July 08, 2020, 03:07:49 am »
"Because UTC is exactly meant to be used as an absolute measure point, then why not (ab)use it for the purpose it was invented for ? (the ADS record using UTC by EPOCH is there for a reason"

Yes there is a reason. There are ADS receivers all over the world. Hundreds of thousands of them. They are the size of a shoe box, a Raspberry Pi computer inside connected to the web and powered by 110v or a battery. Most are privately owned and they supply data to the providers. For a provider to have worldwide coverage would require an hardware instantiation at about 90,000 airports.
 
FPC 3.2.0, Lazarus IDE v2.0.4
 Windows 10 Pro 32-GB
 Intel i7 770K CPU 4.2GHz 32702MB Ram
GeForce GTX 1080 Graphics - 8 Gig
4.1 TB

winni

  • Hero Member
  • *****
  • Posts: 1795
Re: Problems with time and Distance Help Please
« Reply #76 on: July 08, 2020, 03:28:03 am »
Hi!

The newspapers told that Russia got mad about Corona and did not allow any international contact, especially by flight. Now they have checked what a nonsense that is and stopped it.

There is no clear order about the situation.

But: it seems that TRon got a flight that did not touch Russia. And I got one that took the normal route.

Good night
Winni



TRon

  • Hero Member
  • *****
  • Posts: 536
Re: Problems with time and Distance Help Please
« Reply #77 on: July 10, 2020, 10:20:28 pm »
Would you be able to share more with regards to the status field in those ADS-B records ?

I've done some research and the message as you described does not seem to be a standard S-record so your supplier seem to use some custom format.

There is even more to it than that, as this particular flight, flight WN1747 from Milwauki to phoenix @ June 19th, seem to have some particularities (but perhaps that is why you choose to use this flight as an example)

This flight was scheduled to depart from Milwaukee at 19 jun 20:20 UTC (15:10 CDT), but in fact departured at 15:14 CDT (4 minutes late)

This flight was scheduled to arrive at Phoenix at 19 jun 23:50 UTC (16:50 MST), but in fact arrived at 16:42 MST (8 minutes early).

The (EPOCH) timestamp of the S-Record message is 19 jun 23:44, thus recorded two minutes past arrival.

Quote
There are about 20 additional data points but nothing that I can use.
So you say. No reason to doubt that statement but I do wonder.

Because your supplier seem to have a mind of its own about what should and shouldn't be part of those records, things could become messy.

Right now it looks more to me that your supplier witholds (vital) information either because a) your supplier hasn't got those informations to begin with and/or b) attempts to squeeze you out for even more money in case you do wish to obtain the actual information.

winni

  • Hero Member
  • *****
  • Posts: 1795
Re: Problems with time and Distance Help Please
« Reply #78 on: July 10, 2020, 10:31:38 pm »
Hi!

Those supplieres are allways greedy. There could be the big money! If you are a buisiness client and need ALL  data plus more than a 5 digit number of flights you really pay a hell.

I also recovered by checking by myself that the great cirle from Osaka to Amsterdam does not go so wide North like my screenshoot. It should come down way over South  Finnland, then South Sweden way  to Amsterdam.  Don't know what strange things KLM did that day.

Winni

Thaddy

  • Hero Member
  • *****
  • Posts: 10466
Re: Problems with time and Distance Help Please
« Reply #79 on: July 10, 2020, 10:46:29 pm »
Those supplieres are allways greedy.
Winni
It is the other way around.
Even if data as such is in the public domain, you can not simply copy data from a publisher that invested money to show that data. That's theft.
Not the data itself, but stealing from its presentation.
That is a crime in the European union.

On topic: ADS receivers rely on a simple protocol which is open , so why all the fuss? just do it yourself.
« Last Edit: July 10, 2020, 10:59:02 pm by Thaddy »
When you ask a question that is actually answered in the documentation, you are either lazy or a moron.

TRon

  • Hero Member
  • *****
  • Posts: 536
Re: Problems with time and Distance Help Please
« Reply #80 on: July 10, 2020, 10:56:14 pm »
@winni:
Yes, indeed. I have noticed that as well. Most websites/suppliers are so greedy that they not even realise what nonsense they sell.

Even the project that JLWest refers to, the pi's (or so called feeders) that 3th parties use to supply the data to certain websites expects to be payed big numbers, or you must become a feeder (but even then some requests seem to be restricted).

Don't get me wrong on that, as I do understand why as certain commercial entities think it is a good idea to 'borrow' the data (by the millions) from such websites so resell them for big bucks again. The project that JLWest referred to was such a victim, and therefor they made the decision to almost not share anything anymore unless you are an actual registered feeder.

With regards to the Osaka - Amsterdam flight: Yeah, there seems to be something strange that happened that day. Of course it is always possible there was some sort of NATO exercise or some temporary air-space lock (as you suggested) or perhaps something else going on that day that prohibited airlines to use their normal flight-plans. I have no idea, as aviation isn't really my thing.

@JLWest: with regards to take-off. You said you used a standard time-frame for that to calculate your data, but I have come to the conclusion that this number you used is way too optimistic. If you look at the actual flight data from that Phoenix flight then you can see that reaching altitude and therefor optimal cruise-speed took over 15 minutes for that plane to actually realise on that flight. I would love to share this data but I forgot to make a copy of it and now I seem unable to locate it anymore as most of those websites only keep track/storage of such data for a couple of days/weeks
« Last Edit: July 10, 2020, 10:59:54 pm by TRon »

winni

  • Hero Member
  • *****
  • Posts: 1795
Re: Problems with time and Distance Help Please
« Reply #81 on: July 10, 2020, 10:56:38 pm »
Hi!

Which way round it is - might be a great discussion.

But who punishes it?

Like MP Gerhard Schröder violated international law by starting  the war against Serbia. The first war of aggression since Adolf Hitler. A socialdemokrat and  a green foreign minister. 1999.

Nobody cares.

Winni

winni

  • Hero Member
  • *****
  • Posts: 1795
Re: Problems with time and Distance Help Please
« Reply #82 on: July 10, 2020, 11:05:12 pm »
@winni:

With regards to the Osaka - Amsterdam flight: Yeah, there seems to be something strange that happened that day. Of course it is always possible there was some sort of NATO exercise or some temporary air-space lock (as you suggested) or perhaps something else going on that day that prohibited airlines to use their normal flight-plans. I have no idea, as aviation isn't really my thing.


Hi!

Just had another idea - a press note that was mostly hidden:
In Western Russia there was extended radioactivity.  They measured in in Skandinavia but it was not dangerous. So nobody cared about  it. Maybe the Russians knew more than we and closed the airspace?????

Winni

« Last Edit: July 10, 2020, 11:08:46 pm by winni »

TRon

  • Hero Member
  • *****
  • Posts: 536
Re: Problems with time and Distance Help Please
« Reply #83 on: July 10, 2020, 11:19:04 pm »
On topic: ADS receivers rely on a simple protocol which is open , so why all the fuss? just do it yourself.
1. I don't think if I would install such a receiver that I am able to to receive all data from all flights from the whole world. Not sure, but an educated guess  ;)
2. I wanted to make sure user JLWest understands that his supplier isn't providing the actual data that comes from these transmissions, it seems to be an excerpt of it.
3. There is no fuss other than user JLWest picked two flights for us to work with and both flights seem to have something strange (or at least out of the ordinary) going on.

winni

  • Hero Member
  • *****
  • Posts: 1795
Re: Problems with time and Distance Help Please
« Reply #84 on: July 10, 2020, 11:37:57 pm »
Hi TRon!

All those "airplane providers" try to convince you to install a ADS reveiver at your window board and send the data to the "Big Boss". Here and then I look flightradar24 and they also try to convince everybody. So they might get more detailed data from a city or even got one one sender at the end of the world ( Australian Outback, North Norway, Greek small Islands ....).

There might be some deviations because of windstorm, political reasons ...

BUT JLWESTs results are sometimes astonshing.
The first he should clean up his form with 87 labels. I allways get lost there .

Winni

JLWest

  • Hero Member
  • *****
  • Posts: 845
Re: Problems with time and Distance Help Please
« Reply #85 on: July 11, 2020, 02:21:48 am »
Yea I can get better data at about $1,225 a month with a yearly subscription. The absolute best ASD-B data is with Cirium and/or maybe OAG. Both have excellent selection of API Calls and provide great data. The one I use is third tier. But the project is for someone else. I'm just doing the work for WT3.

No good deed goes unpunished.

As for ASD-B receivers, they run on a Raspberry Pi computer  connected to an antenna and to the network with an open source of specialized code. They are line of sight with a range of 25 to 30 miles. Therefore the providers needs a bunch for worldwide coverage. One near every airport. The provider makes money two ways. Selling the data and a fee if they will omit certain NS and military flights from their data. As I understand it, yea. There is one provider that will provide all ASD-B data raw, unfiltered. but you can't use it in a commercial product.

Because  this data is going to be used in a Flight Simulator product (X-Plane 11 and World Traffic-3) we don't have to be that accurate.

FPC 3.2.0, Lazarus IDE v2.0.4
 Windows 10 Pro 32-GB
 Intel i7 770K CPU 4.2GHz 32702MB Ram
GeForce GTX 1080 Graphics - 8 Gig
4.1 TB

TRon

  • Hero Member
  • *****
  • Posts: 536
Re: Problems with time and Distance Help Please
« Reply #86 on: July 11, 2020, 04:18:07 am »
Yea I can get better data at about $1,225 a month with a yearly subscription.
*ouch*

That is no fun for a hobbyist such as myself.

Quote
No good deed goes unpunished.
Seems that way  :)

Quote
Because  this data is going to be used in a Flight Simulator product (X-Plane 11 and World Traffic-3) we don't have to be that accurate.
Of course, only you can be the real judge of that. I only report what seems to be obvious for/to me.

For instance, and afaik (which isn't much) the ADS-B 'status' doesn't know anything about a status such as "landed". It is however able to provide information whether a message originates from the plane being "on-ground" (indicated by a one) or not (indicated by a zero).

Therefor, when a message is being indicated as 'on-ground' then, in order to determine whether the 'waste' time should be compensated at time of departure or arrival you should use the distance to either of those two locations and determine which position is closer to the plane's current position.

But there we have the problem that we do not know which exact part of the 'waste'-time should be added to the departure or arrival because it depends whether or not the plane has already partaken in a specific action (that belongs to the waste-time) or not (and for how long the plane is already doing so).

Perhaps minor details but, for sure has a bigger impact when just fumbling around.

Right now, with the information provided, it is just a pure guessing game which (waste) time should be added where exactly. (and I am sorry for keep calling it waste, as I simply lack better wording for it so that it depicts both departure and arrival locations activities done before the plane is actual cruise-flight state).
« Last Edit: July 11, 2020, 04:20:42 am by TRon »

winni

  • Hero Member
  • *****
  • Posts: 1795
Re: Problems with time and Distance Help Please
« Reply #87 on: July 11, 2020, 06:51:10 pm »

But there we have the problem that we do not know which exact part of the 'waste'-time should be added to the departure or arrival because it depends whether or not the plane has already partaken in a specific action (that belongs to the waste-time) or not (and for how long the plane is already doing so).

Perhaps minor details but, for sure has a bigger impact when just fumbling around.

Right now, with the information provided, it is just a pure guessing game which (waste) time should be added where exactly. (and I am sorry for keep calling it waste, as I simply lack better wording for it so that it depicts both departure and arrival locations activities done before the plane is actual cruise-flight state).

Hi!

If you really want to know the second of the lift off and the touch down you need the exact height of the airplane.
That info you get either direct from the plane or from the tower.

Even a page like flightradar24 often has often the same symptom:
The plane  starts the approach for landing - and suddenly it is stuck at some hundred feet height:

It vanished behind some hill and you will get no info anymore until it moves on a runway.
So with little money you will never get exact data.

So we will have to do some rounding - as near as we can assume.


Winni

JLWest

  • Hero Member
  • *****
  • Posts: 845
Re: Problems with time and Distance Help Please
« Reply #88 on: July 11, 2020, 07:13:31 pm »
ASD-B data comes from the transponder in the plane. It transmits the ASD-B periodically, not constantly like the transponder setting. The receivers have a line of sight 20, 25 mile range. ASD-B was never meant to give accurate location information. However, they do transmit Lat/Lon altitude, speed and heading information. I just have a lousy provider. When the Transponder was turned off in flight MD370 his location was no longer reported on ASD-B. But there is no receivers in Indian ocean anyway.

   
FPC 3.2.0, Lazarus IDE v2.0.4
 Windows 10 Pro 32-GB
 Intel i7 770K CPU 4.2GHz 32702MB Ram
GeForce GTX 1080 Graphics - 8 Gig
4.1 TB

winni

  • Hero Member
  • *****
  • Posts: 1795
Re: Problems with time and Distance Help Please
« Reply #89 on: July 11, 2020, 07:24:45 pm »
Hi!

There are a lot of "blank" area with no receivers. Take the center of Afrika: nobody knows where you are.

The Indian Ocean is indeed poor. In the north you got some holiday islands plus Diego Garcia Base, owned by GB but used by USA. There they started the bombers to the Iraq.

But between South Afrika and Perth in Australia there is really nothing. That's where they search for the lost malayan flight MH 370.

Winni
« Last Edit: July 11, 2020, 07:27:40 pm by winni »

 

TinyPortal © 2005-2018