Hawk Wind

Actually the S100 with Hawk winds is about the same price as the Air-Avionics Display S + AHRS.

Richard

Richard, does that include the AHRS? Or is that another $900? Hard to tell from published data, but it looks like they are separate options. The Air came with both.
On Thursday, May 6, 2021 at 12:57:52 PM UTC-7, Richard Pfiffner wrote:
Actually the S100 with Hawk winds is about the same price as the Air-Avionics Display S + AHRS.

Richard

A bit pricey, yes. But then so is taking out a perfectly good ASH-26e engine and replacing it with the fuel-injected version from the ASH31mi along with a rudder from an ASH31 mi. To me a better economic impulse would have been to sell the 26 and buy a 31. Does it all depend on one's definition of "impulse buy"? As for impulse buys, could be the IP from Air-Avionics for their butterfly is available at a reasonable cost for a younger person so inclined. Full disclosure, I have had some very expensive and ill-considered impulse buys. Anyone want to buy "Red Dress" by Richard MacDonald

On Thursday, May 6, 2021 at 10:31:16 AM UTC-7, jfitch wrote:
Air Avionics have been equally circumspect on exactly what they do, and how much each of the 9 axis MEMs sensors contribute to that. Using the magnetometer has some advantages, as the limiting case of straight line flight in steady flow can still produce a wind calculation, also it makes inherent an AHRS which is not possible without it. I'd agree that the result is the most important, I'd pop one in the panel and find out but they are a bit pricey as an impulse purchase - costing somewhat more than an Air Avionics did when they were still sold.
On Thursday, May 6, 2021 at 10:04:42 AM UTC-7, wrote:
On Thursday, 6 May 2021 at 16:54:14 UTC+1, jfitch wrote:
The paper is fairly circumspect on the details of what they are doing.. Their claim that this hasn't been done before seems disingenuous, given that the Air Vario had been out for a number of years producing (or claiming to produce) a similar result. Air's efforts are described in a university published paper from some years ago. Their methods appear to be similar. But I am glad that someone has taken up the challenge that Air Avionics has now dropped. Whether it is better or worse will require installing both in the panel and flying for awhile. The advantages they expound of knowing the true wind in real time are already well known to anyone with an Air Display S who has paid attention to it.
On Thursday, May 6, 2021 at 1:27:24 AM UTC-7, wrote:
On Thursday, 6 May 2021 at 06:48:03 UTC+1, krasw wrote:
On Thursday, 6 May 2021 at 00:15:44 UTC+3, Eric Greenwell wrote:
"The mathematical system theory also answers the question under what conditions
a wind estimation is possible. In the case of a borderline case of an exact
straight flight movement and completely calm air, this is not possible. All
triangles are identical. We (Huang and Meyr) could show, however, that the
random changes in the air movement are sufficient to make the system
"observable.� "
--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
For wind vector you need two TAS-GS difference/track vectors. If they are identical (same direction of flight), you have no wind solution (as stated in paper). Optimum would be two vectors with 90 degrees difference, and measured in extremely short duration (this is how Oudie "live wind" tries to do it, though I haven't got it working). This would give an ok solution in circling flight, but at the same time the angular speed while circling is not very high, so sensing wind vector at different parts of thermal is rather slow (on steep turn with AIR Glide S gives you basically 20-25 separate wind measurements with 1 sec average). In straight flight Hawk is relying on miniscule differences in flight track. Instead of two wind vector components with 90 degree difference in direction they have vectors that have only few degrees difference on average. I would love to see someone comparing wind indications of Hawk and Glide S someday.
Krasw, if you study the paper you will see that your end point is the author's start question i.e. how can you possibly estimate 3D "wind" at high frequency without heading data input from a magnetometer?
The Air Avionics wind and blue ball netto calculations are dependent on data from an accurately reading magnetometer - and installing one of those free from EM fields is its Achilles' heel, and also the reason I never got one when they were still on sale So, to my mind the Hawk method is definitely new - although I am more interesting in finding out whether it works rather than who did what first.

I thought the paper contained a lot detail on the concept and implementation including the statement:

"Mathematical system theory also answers the question under which conditions wind estimation is possible. In the limiting case of an exactly straight-line flight motion and perfectly calm air, this is not possible. All triangles are identical. However, we could show (Huang und Meyr) that the random changes in the airmass movement are sufficient to make the system "observable"."

From this, if true, one might infer that what would be to the pilot "miniscule differences in flight track" would actually yield plenty data for the system to calculate wind.

As for impulse buys, could be the IP from Air-Avionics for their butterfly is available at a reasonable cost for a younger person so inclined.
On Thursday, May 6, 2021 at 10:31:16 AM UTC-7, jfitch wrote:
Air Avionics have been equally circumspect on exactly what they do, and how much each of the 9 axis MEMs sensors contribute to that. Using the magnetometer has some advantages, as the limiting case of straight line flight in steady flow can still produce a wind calculation, also it makes inherent an AHRS which is not possible without it. I'd agree that the result is the most important, I'd pop one in the panel and find out but they are a bit pricey as an impulse purchase - costing somewhat more than an Air Avionics did when they were still sold.
On Thursday, May 6, 2021 at 10:04:42 AM UTC-7, wrote:
On Thursday, 6 May 2021 at 16:54:14 UTC+1, jfitch wrote:
The paper is fairly circumspect on the details of what they are doing.. Their claim that this hasn't been done before seems disingenuous, given that the Air Vario had been out for a number of years producing (or claiming to produce) a similar result. Air's efforts are described in a university published paper from some years ago. Their methods appear to be similar. But I am glad that someone has taken up the challenge that Air Avionics has now dropped. Whether it is better or worse will require installing both in the panel and flying for awhile. The advantages they expound of knowing the true wind in real time are already well known to anyone with an Air Display S who has paid attention to it.
On Thursday, May 6, 2021 at 1:27:24 AM UTC-7, wrote:
On Thursday, 6 May 2021 at 06:48:03 UTC+1, krasw wrote:
On Thursday, 6 May 2021 at 00:15:44 UTC+3, Eric Greenwell wrote:
"The mathematical system theory also answers the question under what conditions
a wind estimation is possible. In the case of a borderline case of an exact
straight flight movement and completely calm air, this is not possible. All
triangles are identical. We (Huang and Meyr) could show, however, that the
random changes in the air movement are sufficient to make the system
"observable.� "
--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
For wind vector you need two TAS-GS difference/track vectors. If they are identical (same direction of flight), you have no wind solution (as stated in paper). Optimum would be two vectors with 90 degrees difference, and measured in extremely short duration (this is how Oudie "live wind" tries to do it, though I haven't got it working). This would give an ok solution in circling flight, but at the same time the angular speed while circling is not very high, so sensing wind vector at different parts of thermal is rather slow (on steep turn with AIR Glide S gives you basically 20-25 separate wind measurements with 1 sec average). In straight flight Hawk is relying on miniscule differences in flight track. Instead of two wind vector components with 90 degree difference in direction they have vectors that have only few degrees difference on average. I would love to see someone comparing wind indications of Hawk and Glide S someday.
Krasw, if you study the paper you will see that your end point is the author's start question i.e. how can you possibly estimate 3D "wind" at high frequency without heading data input from a magnetometer?
The Air Avionics wind and blue ball netto calculations are dependent on data from an accurately reading magnetometer - and installing one of those free from EM fields is its Achilles' heel, and also the reason I never got one when they were still on sale So, to my mind the Hawk method is definitely new - although I am more interesting in finding out whether it works rather than who did what first.

I thought the paper contained a lot detail on the concept and implementation including the statement:

"Mathematical system theory also answers the question under which conditions wind estimation is possible. In the limiting case of an exactly straight-line flight motion and perfectly calm air, this is not possible. All triangles are identical. However, we could show (Huang und Meyr) that the random changes in the airmass movement are sufficient to make the system "observable"."

From this, if true, one might infer that what would be to the pilot "miniscule differences in flight track" would actually yield plenty data for the system to calculate wind.

On Thursday, May 6, 2021 at 1:13:48 PM UTC-7, jfitch wrote:
Richard, does that include the AHRS? Or is that another $900? Hard to tell from published data, but it looks like they are separate options. The Air came with both.
On Thursday, May 6, 2021 at 12:57:52 PM UTC-7, Richard Pfiffner wrote:
Actually the S100 with Hawk winds is about the same price as the Air-Avionics Display S + AHRS.

Richard
I think it comes with the AHRS.

Richard

LX9000 has instantaneous HW/TW box called Cwind. But to get it to work right you need to turn off units and label and ignore the number in the right. The left number is instantaneous HW/TW Calculated from HS-TAS. As important as the Hawk wind, yet free, very simple reliable calculation, and very well hidden feature. Go figure.

Ramy

On Sunday, May 2, 2021 at 9:39:57 PM UTC-7, 2G wrote:
On Sunday, May 2, 2021 at 3:59:20 PM UTC-7, waremark wrote:
On Sunday, 2 May 2021 at 06:58:35 UTC+1, Matthew Scutter wrote:
Would you expect it to function meaningfully differently in the flatlands? Circling wind should work just fine in a homogenous atmosphere, so functioning the same would be ideal.
Similarly I would be surprised if there was improvement in variometer function from an existing well-compensated setup. All I would wish for additionally from my existing variometer is that it would read accurately in the first second of the pullup into a thermal.
Some Butterfly users reported that as you circle in a thermal you can see the wind indicators pointing in from all directions to the centre of the thermal. As to the vario, as someone else has mentioned the key aspiration is for a system which differentiates vertical gusts from horizontal gusts better than a TE vario. Again, the Butterfly was supposed to achieve this.
The best wind indicator I have used in over 40 years of soaring is watching how my circles drift while thermaling - no special sensors, sensor fusion or Kalman filtering required. Second to that is comparing true airspeed to GPS ground speed. I would like to see LXNAV implement a Nav box that differences those two values, however (again, no additional sensors or filtering required).

Tom

So you get the magnetometer with the Hawk option? I guess probably it is in the MEMs sensor they install in every unit and just turn it on?
On Thursday, May 6, 2021 at 3:53:06 PM UTC-7, Richard Pfiffner wrote:
On Thursday, May 6, 2021 at 1:13:48 PM UTC-7, jfitch wrote:
Richard, does that include the AHRS? Or is that another $900? Hard to tell from published data, but it looks like they are separate options. The Air came with both.
On Thursday, May 6, 2021 at 12:57:52 PM UTC-7, Richard Pfiffner wrote:
Actually the S100 with Hawk winds is about the same price as the Air-Avionics Display S + AHRS.

Richard
I think it comes with the AHRS.

Richard

On Thursday, May 6, 2021 at 6:38:00 PM UTC-7, jfitch wrote:
So you get the magnetometer with the Hawk option? I guess probably it is in the MEMs sensor they install in every unit and just turn it on?
On Thursday, May 6, 2021 at 3:53:06 PM UTC-7, Richard Pfiffner wrote:
On Thursday, May 6, 2021 at 1:13:48 PM UTC-7, jfitch wrote:
Richard, does that include the AHRS? Or is that another $900? Hard to tell from published data, but it looks like they are separate options. The Air came with both.
On Thursday, May 6, 2021 at 12:57:52 PM UTC-7, Richard Pfiffner wrote:
Actually the S100 with Hawk winds is about the same price as the Air-Avionics Display S + AHRS.

Richard
I think it comes with the AHRS.

Richard

The magnetometer option is a separate box, and for good reason: you need to position it somewhere free from stray magnetic fields. So, I don't think that Hawk wind uses it. It's not cheap, however:
https://wingsandwheels.com/lxnav-magnetic-compass.html

Tom

On Thursday, 6 May 2021 at 18:54:14 UTC+3, jfitch wrote:
The paper is fairly circumspect on the details of what they are doing. Their claim that this hasn't been done before seems disingenuous, given that the Air Vario had been out for a number of years producing (or claiming to produce) a similar result. Air's efforts are described in a university published paper from some years ago.

Yes, they are ignoring basically everything that has been done with variometer tech during last 25 years.

On 5/7/2021 3:33 AM, krasw wrote:
On Thursday, 6 May 2021 at 18:54:14 UTC+3, jfitch wrote:
The paper is fairly circumspect on the details of what they are doing. Their claim that this hasn't been done before seems disingenuous, given that the Air Vario had been out for a number of years producing (or claiming to produce) a similar result. Air's efforts are described in a university published paper from some years ago.

Yes, they are ignoring basically everything that has been done with variometer tech during last 25 years.

Not ignoring, but purposely avoiding pressure variometry and it's inherent
problems. LXNav has chosen to add Hawk to their varios, so the commercial
implementation of Hawk (currently in the S100) does not ignore conventional
pressure variometer tech. What Jon is wondering, as I am, is how different is
Hawk from the techniques used to drive the Air Vario's "Blue Ball".

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1