Using East and West coordinates together

[Konstantin Gordeev]

Hello!

Does anyone have an experience of using East (E) and West (W) coordinates in one line?

Here is an example:
[ARTCC]
ZZZZ FIR   N087.38.00.000 W168.58.24.000 N065.00.00.000 W168.58.24.000
N065.00.00.000 W168.58.24.000 N064.03.00.000 W172.12.00.000
N064.03.00.000 W172.12.00.000 N061.20.12.000 W177.45.06.000
N061.20.12.000 W177.45.06.000 N060.00.00.000 E180.00.00.000
N060.00.00.000 E180.00.00.000 N054.00.00.000 E169.00.00.000
N054.00.00.000 E169.00.00.000 N045.00.00.000 E150.00.00.000
N045.00.00.000 E150.00.00.000 N054.52.00.000 E150.00.00.000

This is FIR boundary. But when I try to connect coordinate N061.20.12.000 W177.45.06.000 with N060.00.00.000 E180.00.00.000 by line it goes far far away from real position. It seems to me something happens when line cross 180 longitude. Is it a bug?

Edited September 2, 2022 at 09:53 AM by Konstantin Gordeev

[Bernardo Reis]

Can't you use W180?

[Alistair Thomson]

1 hour ago, Bernardo Reis said:

Can't you use W180?

I thought of that too, but what then happens when the next line is followed? Transiting from W180 to E169 might also be problematic, and I don't know what would happen if that next line was left starting with E180 when the last location was W180... if you follow me...

[Ross Carlson]

37 minutes ago, Alistair Thomson said:

I thought of that too, but what then happens when the next line is followed? Transiting from W180 to E169 might also be problematic, and I don't know what would happen if that next line was left starting with E180 when the last location was W180... if you follow me...

Each line is a standalone line segment, so it shouldn't matter. As long as the E/W "sign" is the same for both coordinates on a given line, it should be good. (Unless the line deliberately crosses the prime meridian, of course.)

Edited September 2, 2022 at 06:30 PM by Ross Carlson

[Alistair Thomson]

6 hours ago, Ross Carlson said:

Each line is a standalone line segment, so it shouldn't matter

So using W180 in the highlighted line would stop the "long way round" behaviour? If that is what the problem was.

[Ross Carlson]

21 minutes ago, Alistair Thomson said:

So using W180 in the highlighted line would stop the "long way round" behaviour?

It should, yeah.

[Konstantin Gordeev]

1 hour ago, Ross Carlson said:

It should, yeah.

I tried, but no success. The screen shows how it works now (without modification). If I use W instead of E, line disappears.

Here are the coordinates of whole sector:
N087.38.00.000 W168.58.24.000 N065.00.00.000 W168.58.24.000
N065.00.00.000 W168.58.24.000 N064.03.00.000 W172.12.00.000
N064.03.00.000 W172.12.00.000 N061.20.12.000 W177.45.06.000
N061.20.12.000 W177.45.06.000 N060.00.00.000 E180.00.00.000
N060.00.00.000 E180.00.00.000 N054.00.00.000 E169.00.00.000
N054.00.00.000 E169.00.00.000 N045.00.00.000 E150.00.00.000
N045.00.00.000 E150.00.00.000 N054.52.00.000 E150.00.00.000
N054.52.00.000 E150.00.00.000 N056.00.00.000 E146.00.00.000
N056.00.00.000 E146.00.00.000 N056.25.00.000 E143.25.00.000
N056.25.00.000 E143.25.00.000 N058.00.00.000 E145.45.00.000
N058.00.00.000 E145.45.00.000 N061.00.00.000 E146.00.00.000
N061.00.00.000 E146.00.00.000 N062.00.00.000 E145.00.00.000
N062.00.00.000 E145.00.00.000 N063.34.00.000 E145.30.00.000
N063.34.00.000 E145.30.00.000 N064.00.00.000 E149.40.00.000
N064.00.00.000 E149.40.00.000 N065.45.00.000 E158.00.00.000
N065.45.00.000 E158.00.00.000 N066.33.00.000 E158.00.00.000
N066.33.00.000 E158.00.00.000 N066.33.00.000 E162.00.00.000
N066.33.00.000 E162.00.00.000 N068.40.00.000 E165.00.00.000
N068.40.00.000 E165.00.00.000 N070.30.00.000 E168.00.00.000
N070.30.00.000 E168.00.00.000 N072.30.00.000 E168.00.00.000
N072.30.00.000 E168.00.00.000 N072.00.00.000 E158.00.00.000
N072.00.00.000 E158.00.00.000 N073.12.00.000 E143.35.00.000
N073.12.00.000 E143.35.00.000 N074.20.00.000 E132.00.00.000
N074.20.00.000 E132.00.00.000 N076.20.00.000 E114.43.00.000
N076.20.00.000 E114.43.00.000 N078.00.00.000 E114.45.00.000
N078.00.00.000 E114.45.00.000 N087.38.00.000 W168.58.24.000

 

[Ross Carlson]

Might be a bug then ... W180.00.00.000 is a perfectly valid coordinate, so I don't know why ES would just not draw the line at all. I'll let Gergely or someone else that knows ES better than me speak to that.

As a workaround, you could try using W179.59.59.999.

[Konstantin Gordeev]

10 hours ago, Ross Carlson said:

Might be a bug then ... W180.00.00.000 is a perfectly valid coordinate, so I don't know why ES would just not draw the line at all. I'll let Gergely or someone else that knows ES better than me speak to that.

As a workaround, you could try using W179.59.59.999.

Thank you! Will try. 

By the way, where should I define FIR boundaries? Only in ese file? 

[Gergely Csernak]

I am sorry, but the projection system in the current version of EuroScope does nopt support the lines crossing the 180 longitude.

It is on the TODO list and will be available soon.

[Jonas Eberle]

We also had to apply fixes for that in QuteScoop after no-one noticed that for many years 🙂 . That shows that the _FSS stations around there have gotten more active 🙂

It is a totally different problem for our 3D map probably, but I leave it here. Maybe the approach helps other programs, too:

https://github.com/qutescoop/qutescoop/pull/125
https://github.com/qutescoop/qutescoop/pull/79