(Question)(Not bug report) Does the CRJ use Nav Data ILS positions?

[Ivan Wong CL 11]

Hi,

 

Scenario : Navigraph data AIRAC 2103 downloaded installed. 

 

I see I the nav data folder, that there are text files with airport info n etc. together in the airport text file, there are definitions and coordinates of various stuff , including ILS coordinates. 

 

Question : If I change the ils localizer coordinates, could it reflect on the CRJ's ils approach and where it detected it in the sim ?

 

I tried but seems no effect. 

[JRBarrett 675]

No. Navaids in the sim are embedded in the scenery in BGL files. This includes all VORs, localizers, glide slopes, DMEs, NDBs and marker beacons. In the default sim, they are based on the core nav data supplied by NavBlue. If you use the Navigraph beta replacement core nav data for MSFS, then the navaids will come from that data instead of default. The Navigraph beta sim data contains replacement scenery BGL files (specifically for the navaids) that overrides the default data when placed in the Community folder.
 

The FMS database in the CRJ simply contains information on the various navaids in the sim world, but it does not affect them in any way. 

[Ivan Wong CL 11]

 

19 minutes ago, JRBarrett said:

No. Navaids in the sim are embedded in the scenery in BGL files. This includes all VORs, localizers, glide slopes, DMEs, NDBs and marker beacons. In the default sim, they are based on the core nav data supplied by NavBlue. If you use the Navigraph beta replacement core nav data for MSFS, then the navaids will come from that data instead of default. The Navigraph beta sim data contains replacement scenery BGL files (specifically for the navaids) that overrides the default data when placed in the Community folder.
 

The FMS database in the CRJ simply contains information on the various navaids in the sim world, but it does not affect them in any way. 

 

Hi @JRBarrett

 

Thanks for the explanation.
Just to clarify my understanding:
1. FMS AIRAC Data updated to the CRJ are used for FMS inputs and planning

2. AIRAC Data from Navigraph may also update MSFS's base BGL scenery to their new definitions

3. When planning a flight plan, for example, entering Origin/Dest, and also waypoints, these all gets referenced from the CRJ's internal FMS Nav Data(for example an airway, and what navaids are included in that airway). 

4. However, when actually flying in the sim, and let's say i'm tuned to a VOR/ILS somewhere, that VOR's coordinates/course/height/frequency/etc are all based of MSFS Navigraph Updated database(NOT the crj's internal one, though both by right should be same if both are updated correctly)

 

So,

In summary, the CRJ will follow the VOR from MSFS Core Nav Data, and not the numbers from CRJ's internal nav data. 

 

and in for a second additional summary:
If i find that a VOR or ILS beacon;s coordinates in the sim is different from IRL, and i wanted to "correct" it, I should not dissect CRJ's nav data, rather, i should start on dissecting MSFS Core Nav Data(it's BGL and scenery files) 

Is my understanding correct?

[JRBarrett 675]

6 minutes ago, Ivan Wong CL said:

 

 

Hi @JRBarrett

 

Thanks for the explanation.
Just to clarify my understanding:
1. FMS AIRAC Data updated to the CRJ are used for FMS inputs and planning

2. AIRAC Data from Navigraph may also update MSFS's base BGL scenery to their new definitions

3. When planning a flight plan, for example, entering Origin/Dest, and also waypoints, these all gets referenced from the CRJ's internal FMS Nav Data(for example an airway, and what navaids are included in that airway). 

4. However, when actually flying in the sim, and let's say i'm tuned to a VOR/ILS somewhere, that VOR's coordinates/course/height/frequency/etc are all based of MSFS Navigraph Updated database(NOT the crj's internal one, though both by right should be same if both are updated correctly)

 

So,

In summary, the CRJ will follow the VOR from MSFS Core Nav Data, and not the numbers from CRJ's internal nav data. 

 

and in for a second additional summary:
If i find that a VOR or ILS beacon;s coordinates in the sim is different from IRL, and i wanted to "correct" it, I should not dissect CRJ's nav data, rather, i should start on dissecting MSFS Core Nav Data(it's BGL and scenery files) 

Is my understanding correct?

 

Yes, you are 100 percent correct on all points. 
 

The CRJ’s FMS database (which is derived from real world Jeppesen data) is simply a record of what “should” exist in the sim navaid scenery BGLs, (but may or may not, based on how accurate the core scenery is).

 

This applies to physical navaids, but it does not apply to procedures. The core sim nav data does contain information on RNAV waypoints, but since these are not physical navaids, but merely a list of waypoint names, each with a specific latitude/longitude coordinate, the CRJ does not access or use the core sim nav data for waypoints - it uses its own FMS AIRAC data for that. 
 

Likewise procedures like SIDS and STARS, simply consist of a series of named waypoints which are interconnected. Although the core sim nav data does contain information on these procedures (for use by default MSFS aircraft), the CRJ uses its own FMS AIRAC for those procedures - since the waypoints contained therein are not physical objects.
 

An ILS approach will typically contain waypoint names for the Initial and final approach fixes, which are defined as points on the localizer a specific distance from the runway threshold. If you load an ILS approach in the CRJ, the approach IAF and IF fixes that appear on the MFD come from the FMS database, but the actual ILS transmitter itself that the Nav radio tunes to, is contained in the scenery BGLs. 
 

The scenery BGL files will contain information on the latitude/longitude of an ILS localizer transmitter, its frequency and identifier, the magnetic heading and width of the localizer beam, its reception range, and the specific airport runway it is linked to.

 

Likewise for the associated glideslope transmitter, it will have lat/lon coordinates, frequency, the angle of the glideslope and the reception range.

 

My experience has been that the navaid data in the Navigraph beta replacement core data is quite accurate - and generally more up-to-date than the MSFS default data.

 

At present there is no easy way to directly edit the data in the core scenery navaid BGLs for things like VORs, NDBs etc. Rather than changing the data in the core BGLs, the Navigraph beta data provides its own set of BGL files that override the default files.

 

The SDK airport scenery editor that can be accessed from within  the sim in DEV mode can modify airport ILS data, but the process is not very straightforward. 

[Ivan Wong CL 11]

3 minutes ago, JRBarrett said:

 

Yes, you are 100 percent correct on all points. 
 

The CRJ’s FMS database (which is derived from real world Jeppesen data) is simply a record of what “should” exist in the sim navaid scenery BGLs, (but may or may not, based on how accurate the core scenery is).

 

This applies to physical navaids, but it does not apply to procedures. The core sim nav data does contain information on RNAV waypoints, but since these are not physical navaids, but merely a list of waypoint names, each with a specific latitude/longitude coordinate, the CRJ does not access or use the core sim nav data for waypoints - it uses its own FMS AIRAC data for that. 
 

Likewise procedures like SIDS and STARS, simply consist of a series of named waypoints which are interconnected. Although the core sim nav data does contain information on these procedures (for use by default MSFS aircraft), the CRJ uses its own FMS AIRAC for those procedures - since the waypoints contained therein are not physical objects.
 

An ILS approach will typically contain waypoint names for the Initial and final approach fixes, which are defined as points on the localizer a specific distance from the runway threshold. If you load an ILS approach in the CRJ, the approach IAF and IF fixes that appear on the MFD come from the FMS database, but the actual ILS transmitter itself that the Nav radio tunes to, is contained in the scenery BGLs. 
 

The scenery BGL files will contain information on the latitude/longitude of an ILS localizer transmitter, its frequency and identifier, the magnetic heading and width of the localizer beam, its reception range, and the specific airport runway it is linked to.

 

Likewise for the associated glideslope transmitter, it will have lat/lon coordinates, frequency, the angle of the glideslope and the reception range.

 

My experience has been that the navaid data in the Navigraph beta replacement core data is quite accurate - and generally more up-to-date than the MSFS default data.

 

At present there is no easy way to directly edit the data in the core scenery navaid BGLs for things like VORs, NDBs etc. Rather than changing the data in the core BGLs, the Navigraph beta data provides its own set of BGL files that override the default files.

 

The SDK airport scenery editor that can be accessed from within  the sim in DEV mode can modify airport ILS data, but the process is not very straightforward. 

 

 

That is some golden nuggets of info here. Thanks for the knowledge download. 

 

Yes, it's not very straightforward at the moment to directly edit a localizer's data, as there are package priorities being loaded, as well as overwritten, as well as navigraph's data is in BGL format. Asobo's SDK need to mature more for the community to start fixing their airports (they have alot of auto gen airports, but it'll take better tools available to the community to make it easier for a public effort to correct them to real life, be it scenery or nav data)

 

I'm using Navigraph's data, whether the ILS localizer coordinates is really wrong or not in IRL, most probably not? =). But either way, I'm just messing around with the Nav datas in the core and CRj's folder in an attempt to shift localizer to it's IRL antenna position. Your explanation directly correlates with what i find, which is editing CRJ's nav data for the localizer's position does nothing to CRJ's nav receiver. 

 

Thanks for alleviating my curiosity and i can rest well tonight.

[JRBarrett 675]

1 minute ago, Ivan Wong CL said:

 

 

That is some golden nuggets of info here. Thanks for the knowledge download. 

 

Yes, it's not very straightforward at the moment to directly edit a localizer's data, as there are package priorities being loaded, as well as overwritten, as well as navigraph's data is in BGL format. Asobo's SDK need to mature more for the community to start fixing their airports (they have alot of auto gen airports, but it'll take better tools available to the community to make it easier for a public effort to correct them to real life, be it scenery or nav data)

 

I'm using Navigraph's data, whether the ILS localizer coordinates is really wrong or not in IRL, most probably not? =). But either way, I'm just messing around with the Nav datas in the core and CRj's folder in an attempt to shift localizer to it's IRL antenna position. Your explanation directly correlates with what i find, which is editing CRJ's nav data for the localizer's position does nothing to CRJ's nav receiver. 

 

Thanks for alleviating my curiosity and i can rest well tonight.

You’re welcome.

 

The BGL file structure in MSFS used for navaids is similar to FSX and P3D, but not 100 percent the same, and some of the data is in different files. In FSX/P3D airport scenery is contained in a file beginning with the letters “APX”, such as “APX10870.bgl”, and any ILS data for the airport will also be that same APX file.

In MSFS, the airport scenery is still in an APX file, but ILS data is split out into a separate file beginning with the letters “NAX”, so the ILS would be in “NAX10870.bgl”. The NAX file will also be in a completely separate folder than the APX file.

 

Airport scenery design and modification is an entire topic of its own. There is a lot of good information at FSDeveloper.com There is also now an alpha version of the famous ADE airport scenery editor that is compatible with MSFS, and can do a lot of airport editing without having to use the airport scenery editor in the sim.

 

 

[Secondator 643]

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