why does f10 map utm coordinates differ from tsd map coordinates?

[bephanten]

i am trying learn tsd waypoint creation. after cold start, when i create a wp using f10 map coordinates, that wp takes me to a non desired point. 

i create a pre-flight wp in mission editor directing to the same point and i find the coordinates are different from f10 map coordinates.

what is the reason for the discrepancy?

 

[Floyd1212]

You will need to provide some screenshots or something of what you are doing for us to evaluate what the problem might be.

Are you truncating the MGRS coordinates so they are 4-digit precision, which is what the Apache is looking for?

So parking pad 29 at Senaki

Goes in as 38TKM 5593 8109

Which is right where it should be.

 

[bephanten]

Didn't know about 4 digit truncation.  I was entering the coordinate as it is. Thanks. 

[Shadok]

Sorry for the off topic,

What keyboard shortcut is used to bring up the coordinates window on the map (F10)?

thank

Edited August 14, 2024 by Shadok

[LorenLuke]

13 minutes ago, Shadok said:

Sorry for the off topic,

What keyboard shortcut is used to bring up the coordinates window on the map (F10)?

thank

 

Left ALT + Left Click

Alternatively, coordinates for where your mouse cursor currently is are displayed in the top left corner of the screen.

[Recluse]

On 8/14/2024 at 1:26 AM, LorenLuke said:

Left ALT + Left Click

Alternatively, coordinates for where your mouse cursor currently is are displayed in the top left corner of the screen.

...and you can toggle that top left corner display with Left Alt-Y

[LorenLuke]

22 hours ago, Recluse said:

...and you can toggle that top left corner display with Left Alt-Y

To be honest, the reason I didn't also put this is because I don't think it's actually 'Y', but rather based on the location of the key in the keyboard, i.e. some keyboards, like the German one,are QWERTZ, and I believe it's their LAlt+Z that does this function... so Left Alt+<Whatever is between R and U> is probably the best, though not the most concise, description of that key combo.

[Recluse]

4 hours ago, LorenLuke said:

To be honest, the reason I didn't also put this is because I don't think it's actually 'Y', but rather based on the location of the key in the keyboard, i.e. some keyboards, like the German one,are QWERTZ, and I believe it's their LAlt+Z that does this function... so Left Alt+<Whatever is between R and U> is probably the best, though not the most concise, description of that key combo.

Good point!  Thanks for the clarification. 

[Antix70]

I forget where I heard it, but if the 5TH digit is above 5, you round up the 4TH digit. So if it's 81037, you'd input 8104 into the KU. If it's 81032, you'd just input 8103.

Just what I heard, so it's something I've always done, and it works in my experience.

[Floyd1212]

I think this has been discussed here before, and the suggested practice is to truncate the last digit.

I think it had to do with how some grids are actually slivers and not an entire square. In most cases rounding up will do no harm, but in other cases it may be a problem.

Maybe someone else has a more concrete example of this... 

[heloguy]

On 8/31/2024 at 3:50 PM, Floyd1212 said:

I think this has been discussed here before, and the suggested practice is to truncate the last digit.

I think it had to do with how some grids are actually slivers and not an entire square. In most cases rounding up will do no harm, but in other cases it may be a problem.

Maybe someone else has a more concrete example of this... 

Funny, this discussion was just being had in a Discord channel.

 

MGRS accuracy is based on how many digits.  A 10 digit grid is accurate to 1m.  An 8 digit grid is accurate to 10m, and is what the 64 receives on the KU.  Whether or not you decide to round depends on how accurate you care to be.

 

Example:  37SDA2667733703 is the actual location on the ground you want to nav/slew to.  If you round, the grid would be input as 37SDA26683370, which is 3m off in northing and easting.  If you don't and just truncate, it would be 37SDA26673370, which is 7m off in easting, and 3m off in northing.

 

Obviously, if there's a 5 on the end, it's pretty much a toss up on which is more accurate, but, my OCD makes me round.