rragan Posted June 18, 2017 Report Share Posted June 18, 2017 I had to do a projection using magnetic North. The iPhone Compass can be set to show either. Would changing the compass allow Cachly to do a projection using one or the other North? One or the other may be needed for a cache. Quote Link to comment Share on other sites More sharing options...
1 rragan Posted June 19, 2017 Author Report Share Posted June 19, 2017 I just did an experiment and returned to find your note. As you say, the Compass plays no role. I was trying to project a final location and using 52° magnetic North was specified. Using Cachly project gives the right answer for true North but not magnetic. I looked up the local declination of 13.5 degrees and corrected the heading to 65° and got the correct answer. It would be wonderful if projection could let you choose true or magnetic for the heading but declination varies by location. If you could read out the compass and compare to GPS to get local declination for magnetic, that would be cool but I don't know if that is possible. I found a free Declination app so that will suffice for the rare case the CO wants. Magnetic North projection. Nic Hubbard 1 Quote Link to comment Share on other sites More sharing options...
0 Nic Hubbard Posted June 19, 2017 Report Share Posted June 19, 2017 The compass wouldn't affect the actual projection math. Can you show me the cache or explain more what you are meaning? Quote Link to comment Share on other sites More sharing options...
0 DerLakaiMS Posted June 19, 2017 Report Share Posted June 19, 2017 I guess this is basically requires to calculate the deviation between the coordinate system and the magnetic north based on the current location, as done e.g. in http://www.geomag.nrcan.gc.ca/calc/mdcal-en.php Quote Link to comment Share on other sites More sharing options...
0 HikingSeal Posted July 17, 2017 Report Share Posted July 17, 2017 Related to this issue, when projecting a waypoint, does Cachly use your current position or the cache coordinates? I see a selection a couple items up but I don't think that is related to projection. In addition to rragan's request for selection of magnetic vs true, I'd add a request to select "project from? current position or cache coordinates" Quote Link to comment Share on other sites More sharing options...
0 Bolling Posted July 17, 2017 Report Share Posted July 17, 2017 1 hour ago, HikingSeal said: Related to this issue, when projecting a waypoint, does Cachly use your current position or the cache coordinates? I see a selection a couple items up but I don't think that is related to projection. In addition to rragan's request for selection of magnetic vs true, I'd add a request to select "project from? current position or cache coordinates" The Projection is from the grey coordinates in the add waypoint section. You can select a preset coordinates of manually enter any coordinates you want to. The Projection will be from these coordinates. The grey coordinates will turn red after you've calculated a Projection. Quote Link to comment Share on other sites More sharing options...
Question
rragan
I had to do a projection using magnetic North. The iPhone Compass can be set to show either. Would changing the compass allow Cachly to do a projection using one or the other North? One or the other may be needed for a cache.
Link to comment
Share on other sites
5 answers to this question
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.