If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#41
|
|||
|
|||
Alternative magnetic compass
On Friday, October 30, 2015 at 5:00:02 PM UTC-4, jfitch wrote:
On Friday, October 30, 2015 at 1:03:52 PM UTC-7, Mike the Strike wrote: I should also remind everyone that GPS-derived bearings only work when you are moving with respect to the ground. Just remember this if you're stationary or even moving backwards in wave. Mike There are GPS compasses that do not depend on motion for operation. Doubt anyone has one in a glider though. I don't think there is such a thing as GPS compass, regardless if you are moving or not. GPS is measuring your position, it has nothing to do with measurement of magnetic field. |
#43
|
|||
|
|||
Alternative magnetic compass
On Friday, October 30, 2015 at 2:20:55 PM UTC-7, Andrzej Kobus wrote:
I don't think there is such a thing as GPS compass, regardless if you are moving or not. GPS is measuring your position, it has nothing to do with measurement of magnetic field. You can determine orientation (including direction) by using difference in 3D position of two GPS receivers (actually their antennae) mounted at a fixed displacement from each other. It's a bit more complicated than it sounds, as ideally, the two GPS receivers will have synchronized clocks and be using the same satellites for their position solutions. So, the receivers used are quite specialized. |
#44
|
|||
|
|||
Alternative magnetic compass
On Friday, October 30, 2015 at 5:43:43 PM UTC-4, wrote:
On Friday, October 30, 2015 at 2:20:55 PM UTC-7, Andrzej Kobus wrote: I don't think there is such a thing as GPS compass, regardless if you are moving or not. GPS is measuring your position, it has nothing to do with measurement of magnetic field. You can determine orientation (including direction) by using difference in 3D position of two GPS receivers (actually their antennae) mounted at a fixed displacement from each other. It's a bit more complicated than it sounds, as ideally, the two GPS receivers will have synchronized clocks and be using the same satellites for their position solutions. So, the receivers used are quite specialized. You are right, with two receivers and antennas far apart to mitigate the errors it is possible. Not something that one would want to mount in an aircraft. |
#45
|
|||
|
|||
Alternative magnetic compass
On Friday, October 30, 2015 at 4:49:16 PM UTC-6, Andrzej Kobus wrote:
On Friday, October 30, 2015 at 5:43:43 PM UTC-4, wrote: On Friday, October 30, 2015 at 2:20:55 PM UTC-7, Andrzej Kobus wrote: I don't think there is such a thing as GPS compass, regardless if you are moving or not. GPS is measuring your position, it has nothing to do with measurement of magnetic field. You can determine orientation (including direction) by using difference in 3D position of two GPS receivers (actually their antennae) mounted at a fixed displacement from each other. It's a bit more complicated than it sounds, as ideally, the two GPS receivers will have synchronized clocks and be using the same satellites for their position solutions. So, the receivers used are quite specialized. You are right, with two receivers and antennas far apart to mitigate the errors it is possible. Not something that one would want to mount in an aircraft. Been done. Check out Septentrio. http://www.navtechgps.com/assets/1/7...0415_41_DS.pdf |
#46
|
|||
|
|||
Alternative magnetic compass
On Fri, 30 Oct 2015 15:49:14 -0700, Andrzej Kobus wrote:
On Friday, October 30, 2015 at 5:43:43 PM UTC-4, wrote: On Friday, October 30, 2015 at 2:20:55 PM UTC-7, Andrzej Kobus wrote: I don't think there is such a thing as GPS compass, regardless if you are moving or not. GPS is measuring your position, it has nothing to do with measurement of magnetic field. You can determine orientation (including direction) by using difference in 3D position of two GPS receivers (actually their antennae) mounted at a fixed displacement from each other. It's a bit more complicated than it sounds, as ideally, the two GPS receivers will have synchronized clocks and be using the same satellites for their position solutions. So, the receivers used are quite specialized. You are right, with two receivers and antennas far apart to mitigate the errors it is possible. Not something that one would want to mount in an aircraft. You could get a reliable heading with a fluxgate (solid state) compass but not, as you say, with a single GPS receiver. -- martin@ | Martin Gregorie gregorie. | Essex, UK org | |
#47
|
|||
|
|||
Alternative magnetic compass
On Wednesday, October 28, 2015 at 10:32:51 AM UTC-4, wrote:
A sailplane's Flight Manual usually requires a magnetic compass (or an aviation compass)as minimum equipment. Well, panel space has become less available and you are seeing fewer sailplanes with panel or glare-shield mounted 2.25 Airpath C2xxx or PAI-700 aircraft specific compasses. Grob Astir CS does not require as minimum equipment. https://www.dropbox.com/s/yjlrf96sbf...%20PM.png?dl=0 |
#48
|
|||
|
|||
Alternative magnetic compass
Please correct me if I am wrong, but doesn't the Butterfly S and the LX90XX with compass option both have fluxgate compass? One would think with these instruments we would not have to have a whiskey compass, that just takes panel/glare-shield space.
On Friday, October 30, 2015 at 5:24:17 PM UTC-7, Martin Gregorie wrote: You could get a reliable heading with a fluxgate (solid state) compass but not, as you say, with a single GPS receiver. -- martin@ | Martin Gregorie gregorie. | Essex, UK org | |
#49
|
|||
|
|||
Alternative magnetic compass
On Friday, October 30, 2015 at 8:47:15 PM UTC-4, Jonathan St. Cloud wrote:
Please correct me if I am wrong, but doesn't the Butterfly S and the LX90XX with compass option both have fluxgate compass? One would think with these instruments we would not have to have a whiskey compass, that just takes panel/glare-shield space. Perhaps LXNAV has the best chance of approval as the new LXNAV Compass module is advertised as a magnetic compass and sold as a separate (add-on) feature. A better job of "wordsmanship" than Air Avionics' Butterfly S. If only the sailplane manufactures would release a Technical Bulletin stating these devices satisfy intention. But in today's world of government oversight and manufacture's liability risk, a snowball in hell has a better chance. |
#50
|
|||
|
|||
Alternative magnetic compass
On Friday, October 30, 2015 at 5:47:15 PM UTC-7, Jonathan St. Cloud wrote:
Please correct me if I am wrong, but doesn't the Butterfly S and the LX90XX with compass option both have fluxgate compass? One would think with these instruments we would not have to have a whiskey compass, that just takes panel/glare-shield space. On Friday, October 30, 2015 at 5:24:17 PM UTC-7, Martin Gregorie wrote: You could get a reliable heading with a fluxgate (solid state) compass but not, as you say, with a single GPS receiver. -- martin@ | Martin Gregorie gregorie. | Essex, UK org | The Butterfly S doesn't have a compass option, it has the compass as a standard feature. The issue might be whether regulations require a TSO'd compass. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Need help! Magnetic Compass Errors! | kha0z | Piloting | 14 | January 3rd 09 03:20 AM |
Why are headings still magnetic? | Mxsmanic | Piloting | 87 | September 11th 06 05:34 PM |
compass turns with high mounted compass (Cessna 152) | Ray | Instrument Flight Rules | 22 | April 7th 05 07:39 AM |
Aircraft Magnetic Compass | Quilljar | Simulators | 5 | July 11th 04 03:08 PM |
Do you use your magnetic compass? | Roger Long | Piloting | 42 | May 25th 04 12:08 PM |