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 |
#11
|
|||
|
|||
|
#13
|
|||
|
|||
Of course the problem is which 5 out of the 7 in a particular thermal do you
track? :-) Ian "Eric Greenwell" wrote in message ... Andy Durbin wrote: (Ramy Yanetz) wrote in message These devices should be capable to tell you if you are in a collision course, not just warn you of a nearby aircraft. Earlier someone posted a link to a new device which also calculate collision course while thermaling! If you thermal too close to someone else it should warn you. But how close is *too close*? I am perfectly comfortable cranked up at a 50 deg bank with someone opposite me doing the same thing, but very uncomfortable if another glider joins with the same separation and puts me in their blind spot. To be effective in providing warnings the device would have to continuously predict collisions based not only on the current trajectory of each aircraft, but also predict collisions based on all possible future trajectories for the next say 30 seconds. Try resolving that mess when there are 30+ gliders at the top of the same thermal waiting for a contest start. The false alarm rate would be unacceptable. I think Andy is right, but I don't think that situation is the one that produces the most collisions. My undocumented impression is the majority involve just a few gliders, often just two. The computations for two or three gliders should be easy compared to 6 or more. During thermalling or beating back and forth on a ridge, gliders don't change relative altitude very much, so this much reduces the potential paths. So, a system that worked for 2 or 3 gliders would be useful, and as experience was gained with it, I think it would be continually upgraded to cover situations with more gliders. Even if it didn't work for more than even 5 gliders, that would cover most situations. -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
#14
|
|||
|
|||
"Ramy Yanetz" wrote in message .com...
See my other reply below. These devices should be capable to warn you of imminent collision even while thermaling, not just warn you of nearby aircraft. And if they currently don't, they will in the near future. It should not be too difficult to compute collision courses. That is exactly what FLARM does. |
#15
|
|||
|
|||
"Eric Greenwell" wrote in message
... Andy Durbin wrote: (Ramy Yanetz) wrote in message These devices should be capable to tell you if you are in a collision course, not just warn you of a nearby aircraft. Earlier someone posted a link to a new device which also calculate collision course while thermaling! If you thermal too close to someone else it should warn you. But how close is *too close*? I am perfectly comfortable cranked up at a 50 deg bank with someone opposite me doing the same thing, but very uncomfortable if another glider joins with the same separation and puts me in their blind spot. To be effective in providing warnings the device would have to continuously predict collisions based not only on the current trajectory of each aircraft, but also predict collisions based on all possible future trajectories for the next say 30 seconds. Try resolving that mess when there are 30+ gliders at the top of the same thermal waiting for a contest start. The false alarm rate would be unacceptable. I think Andy is right, but I don't think that situation is the one that produces the most collisions. My undocumented impression is the majority involve just a few gliders, often just two. The computations for two or three gliders should be easy compared to 6 or more. During thermalling or beating back and forth on a ridge, gliders don't change relative altitude very much, so this much reduces the potential paths. So, a system that worked for 2 or 3 gliders would be useful, and as experience was gained with it, I think it would be continually upgraded to cover situations with more gliders. Even if it didn't work for more than even 5 gliders, that would cover most situations. -- Change "netto" to "net" to email me directly This still leaves the problem I think Andy was getting at of what is the acceptable false positive:false negative ratio? Too many false positives and pilots won't use it. False negatives would lead to collisions, deaths and, at least in the US, lawsuits that would likely put the manufacturer out of business. Brent |
#16
|
|||
|
|||
Whatever happened to teaching good look out and airmanship?
|
#17
|
|||
|
|||
Good for you! That's the best contribution to this thread I've seen.
David Starer "Dave Martin" wrote in message ... Whatever happened to teaching good look out and airmanship? |
#18
|
|||
|
|||
Good for you! That's the best contribution to this thread I've seen.
David Starer "Dave Martin" wrote in message ... Whatever happened to teaching good look out and airmanship? |
#19
|
|||
|
|||
"303pilot" brentUNDERSCOREsullivanATbmcDOTcom wrote in message ... "Eric Greenwell" wrote in message ... Andy Durbin wrote: (Ramy Yanetz) wrote in message These devices should be capable to tell you if you are in a collision course, not just warn you of a nearby aircraft. Earlier someone posted a link to a new device which also calculate collision course while thermaling! If you thermal too close to someone else it should warn you. But how close is *too close*? I am perfectly comfortable cranked up at a 50 deg bank with someone opposite me doing the same thing, but very uncomfortable if another glider joins with the same separation and puts me in their blind spot. To be effective in providing warnings the device would have to continuously predict collisions based not only on the current trajectory of each aircraft, but also predict collisions based on all possible future trajectories for the next say 30 seconds. Try resolving that mess when there are 30+ gliders at the top of the same thermal waiting for a contest start. The false alarm rate would be unacceptable. I think Andy is right, but I don't think that situation is the one that produces the most collisions. My undocumented impression is the majority involve just a few gliders, often just two. The computations for two or three gliders should be easy compared to 6 or more. During thermalling or beating back and forth on a ridge, gliders don't change relative altitude very much, so this much reduces the potential paths. So, a system that worked for 2 or 3 gliders would be useful, and as experience was gained with it, I think it would be continually upgraded to cover situations with more gliders. Even if it didn't work for more than even 5 gliders, that would cover most situations. -- Change "netto" to "net" to email me directly This still leaves the problem I think Andy was getting at of what is the acceptable false positive:false negative ratio? Too many false positives and pilots won't use it. False negatives would lead to collisions, deaths and, at least in the US, lawsuits that would likely put the manufacturer out of business. Brent We can't ask for perfection or nothing will ever be available. It seems to me that there are two indications we should be looking for in a basic anti-collision device. 1, There are (n) gliders in close proximity - say 1 kilometer. Even simple GPS broadcast devices should be able to determine the number of gliders nearby. It should beep softly when the number changes. (If the device says there are 3 gliders nearby and you can only see 2, you need to keep looking.) 2, If one of these represents a collision danger, the device should give a bearing. The device need only determine that the target is at or near the same altitude, the distance is closing and the relative bearing is nearly constant. If there is only 1% chance of an actual collision, that would get my undivided attention. Of course, collisions can occur with different geometry's but they are rare. The device doesn't need to exactly predict a collision, only that one is possible. That would be enough to get a pilots attention. There are a couple a traffic alert/collision avoidance devices on the market now and they don't seem too worried about legal troubles. Commercial ADS-B devices will not be available for many years. The avionics industry has to sell everybody a Mode S transponder first (Big$), THEN we will get to upgrade to ADS-B(Still more big $). I hope these small efforts within the soaring community produce something we all can use. We sure need it. Bill Daniels |
#20
|
|||
|
|||
"Dave Martin" wrote in message ... Whatever happened to teaching good look out and airmanship? Long and sad experience says it doesn't always work. "Just look outside" is often an excuse for doing nothing about the problem. Bill Daniels |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
For Keith Willshaw... | robert arndt | Military Aviation | 253 | July 6th 04 05:18 AM |
Anti collision lights mods for Arrow 1968?? | Frode Berg | Piloting | 3 | May 20th 04 05:42 AM |
Anti collision light mod for Piper Arrow 1968 model? | Frode Berg | Owning | 4 | May 20th 04 05:16 AM |
New anti collision system for aircrafts, helicopters and gliders | Thierry | Owning | 10 | February 14th 04 08:36 AM |
USAF = US Amphetamine Fools | RT | Military Aviation | 104 | September 25th 03 03:17 PM |