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Are there OpenRocket extensions to let one set higher winds at altitude?

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rocketsam2016

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The most common case for wind is to have much higher speeds at altitude than near the surface. I see that OpenRocket allows extensions to be written, so does anyone know if it is possible (and even better if something has been written!) to allow setting a high altitude wind speed that is different from the ground speed? I'd be most interested in this for more accurate simulation of horizontal movement (weather cocking and then drift under parachute) as a function of launch angle and wind speeds.
 

dhbarr

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I believe RocSim Pro is the only commercially-available/hobbyist-priced source for this kind of analysis.

I would LOVE to be wrong ( e.g. such that multiple analyses can be compared/contrasted vs. actuals )
 

mikec

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The most common case for wind is to have much higher speeds at altitude than near the surface. I see that OpenRocket allows extensions to be written, so does anyone know if it is possible (and even better if something has been written!) to allow setting a high altitude wind speed that is different from the ground speed?
I've done some work on using winds-aloft data to predict landing location (some of this was written up in one of my articles in Sport Rocketry) but I have no idea if the extension framework in OR would allow this to be done. In all honesty I find the description of the framework to be a bunch of Java gibberish.
 

ksaves2

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I've done some work on using winds-aloft data to predict landing location (some of this was written up in one of my articles in Sport Rocketry) but I have no idea if the extension framework in OR would allow this to be done. In all honesty I find the description of the framework to be a bunch of Java gibberish.
I believe the pricey Rocksim Pro was supposed to directly integrate winds aloft data if one feeds it to it. I would expect something like that due to the premium price.
Kurt
 

rocketsam2016

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I believe the pricey Rocksim Pro was supposed to directly integrate winds aloft data if one feeds it to it. I would expect something like that due to the premium price.
Kurt
It looks like it does full randomization and plots of outcomes too which seems very powerful. That being said, I'd love to just be able to say that wind is 5mph at ground, 10mph at 1000feet and 25mph at 10000 feet, have openrocket do some naive interpolation, and get something plausible for how far the rocket will tilt into the wind and then drift back down. I can do the drifting part on my own (I have a spreadsheet that handles 3-layer drift for a dual deployment rocket), but it'd be much nicer to have in OpenRocket and to get the windcocking effects too.
 

mikec

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Should be possible to query https://rucsoundings.noaa.gov/ and get a high-res prediction of winds aloft. I used this with a fair degree of success to predict where high-altitude flights (~20k feet) might land. I just computed the drift on descent, though, not the effects of wind on ascent.
 

rocketsam2016

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Should be possible to query https://rucsoundings.noaa.gov/ and get a high-res prediction of winds aloft. I used this with a fair degree of success to predict where high-altitude flights (~20k feet) might land. I just computed the drift on descent, though, not the effects of wind on ascent.
Are there links to your work? I'd love to see it.

I'm torn between building an app that pulls this data to predict descent drift (something I could certainly pull off with hacky simplifications) and trying to take a look at open rocket extensions to get ascent + descent but forgoing detailed data pulling. The thing is, the weather cocking on ascent and in general the horizontal velocity at the top makes such a difference for the use case I care about: trying to figure out launch rod angles and likely landing spots for flights to 3k to 10k feet landing on a 5k foot field (but with messy areas such that landing within a 3k area is better).

One or both of these may end up as fun personal projects, not that I really have time for more rocketry projects right now :)
 

markkoelsch

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I had Rocksim Pro for a year, and really liked it. It is the only hobby level software that does multiple wind speed and direction at different altitudes. I used it to do the simulation and class three write up on Wildman's Mega Darkstar. I also used it on my home field to try to figure out where a rocket I had previously flown and lost likely ended up. Looked up historical wind, temp, and humidity for the date and time, and pulled in the rkt file. Sure enough, out of 100 iterations of the flight it ended up in a lake/pond 95 times or so. Took a walk around that body of water and found no sign.

If it cost $200 or so I would buy it. $1000 is more than I spend on rockets in a year.
 

mikec

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The "simulation listeners?"
No. For example, see https://sourceforge.net/p/openrocket/mailman/message/30406536/

There's two ways to create plugins:

1. For simple singleton plugins you just need to implement the proper
interface and add the @PluginImplementation annotation. An example is
in ExampleSingletonPlugin.
2. For stateful plugins you implement the interface, and define a
discovery service by extending AbstractService and annotating it. The
service then provides instances of the actual plugin. An example is
in ExamplePlugin / ExampleService.
I have an advanced degree in computer science but this is not specific enough for me.
 

ksaves2

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I had Rocksim Pro for a year, and really liked it. It is the only hobby level software that does multiple wind speed and direction at different altitudes. I used it to do the simulation and class three write up on Wildman's Mega Darkstar. I also used it on my home field to try to figure out where a rocket I had previously flown and lost likely ended up. Looked up historical wind, temp, and humidity for the date and time, and pulled in the rkt file. Sure enough, out of 100 iterations of the flight it ended up in a lake/pond 95 times or so. Took a walk around that body of water and found no sign.

If it cost $200 or so I would buy it. $1000 is more than I spend on rockets in a year.
Only $1000.00 Mark? OMG you're a galdurned slacker I say!:no::surprised::lol: Kurt
 

mikec

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Are there links to your work? I'd love to see it.
Here's a quote from my SR article “Four Miles High: Breaking 20,000 Feet on a K Motor”, May / June 2013 V55, N3:
With relatively low-altitude flights, say less than 5,000 feet, one only needs to launch one test rocket,
watch where it lands, and assume that future flights will trend in the same direction, at least for a few
hours. But above that, there can be very high wind velocities in unexpected directions, and even the
trend of the rocket can come as a surprise.

NOAA makes the results of their atmospheric models available on the Web as “soundings” at high
resolution. Up to 24 hours in advance, these soundings can be used to get a profile of the speed and
direction of winds aloft at about 500 feet vertical resolution all the way up to about 70,000 feet, far
above the typical waiver altitude. I wrote some simple software to compute the drift of a rocket, given
its descent rate, and predict the final landing point. A few hours before heading to the range, I ran the
software, which predicted a landing to the north of the launch site.

Figure DRIFT shows the predicted landing points using pre-flight soundings (retrieved about 16 hours
prior to the flight), post-flight soundings (which is still based on modeling rather than actual
observations), and the actual landing point as determined by a handhand GPS unit. The distance to the
landing site was fairly well predicted (within 15% or so), while the bearing was about 15-20 degrees
off. While obviously not a substitute for tracking, this is an improvement over not having any idea of
which direction the rocket might go.

It should be noted that my software assumes a perfectly-vertical ascent. A future enhancement would
be to integrate the sounding data into a full 6-degree-of-freedom flight simulation program like
OpenRocket; that would also model the effects of the wind profile on the ascent.
 

Voyager1

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Hi folks

There is a free Cambridge Rocketry simulator that provides a useful launch profile and splash pattern that I have been using on and off for a couple of years now. It allows you to enter the multiple level aviation grid point winds from the Met office to simulate an arbitrary number of launches. The launch profiles are displayed in 2D and 3D plots based on the statistical spread of launch parameters. It is very useful, but the rocket design input is not as user-friendly as Open Rocket or RockSim. It is available at

https://cambridgerocket.sourceforge.net/index.html

John
ARA 64
TRA 14574
 

Voyager1

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Well, it seems that the Cambridge simulator is now integrated into an OpenRocket-like GUI. It allows you to build your model as in OpenRocket and you still get the 2D and 3D launch profile and splash plots. This is good news for OpenRocket users.

When you go into edit the simulation it allows you to set the launch conditions and atmospheric conditions. You enter the wind vectors at the different altitudes, including density and temperatures. You can set the number of Monte Carlo runs you want.

Have fun folks!
 

rocketsam2016

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Well, it seems that the Cambridge simulator is now integrated into an OpenRocket-like GUI. It allows you to build your model as in OpenRocket and you still get the 2D and 3D launch profile and splash plots. This is good news for OpenRocket users.

When you go into edit the simulation it allows you to set the launch conditions and atmospheric conditions. You enter the wind vectors at the different altitudes, including density and temperatures. You can set the number of Monte Carlo runs you want.

Have fun folks!
Thanks I'll definitely take a look! Looks to me like the pre-built versions are only for Linux and Windows. Anyone know of existing builds for Mac and/or reasons why it would/wouldn't work if I just compiled it locally?
 

SpaceManMat

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markkoelsch

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Only $1000.00 Mark? OMG you're a galdurned slacker I say!:no::surprised::lol: Kurt
Kurt, not a slacker. Extremely challenged in terms of time. Somewhat challenged in close launch sites ( Bong Rec is home field, and I am particular as to what I will fly there versus weather/wind). A bit constrained on budget- I refuse to go into debt, or damage my family finances, for a hobby.
 

rocketsam2016

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My java's not the best, best way is to look at the ThrustScaler example and simply wade in from there. How deep you need go into the simulation engine workings just depends on how complicated your plugin is.
Yeah I just took a look and it actually doesn't look all that bad. All that really has to be done is to implement a new WindModel that wraps several instances of the existing PinkNoiseWindModel and interpolates between them. It looks pretty easy to inject a new WindModel into the configuration from a plugin, so the annoying part is most likely just figuring out how to make it configurable in the UI. I have a day job, a child, rockets to build, and taxes to do (and I don't particularly like Java.... but let's not start a flame war!) so I won't have a finalized new plugin any time soon :), but I think the hooks are there to do what I want, so I'm going to make this a goal to poke at over the next couple of months. In particular, my intention is to allow the user to set wind speed and direction at altitudes of their choice. Either a fixed number or as many data points as the user wants, depending on how easy the latter is to do with the plugin framework. If I succeed, I'll make sure to at least make my plugin accessible and post it to this thread.
 

AfterBurners

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I believe RocSim Pro is the only commercially-available/hobbyist-priced source for this kind of analysis.

I would LOVE to be wrong ( e.g. such that multiple analyses can be compared/contrasted vs. actuals )
The RS I bought you can set wind speeds and thermals etc. Not sure if its pro, but I paid like $126 for it. Best money spent. It does just about everything
 

rocketsam2016

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https://www.windytv.com/?38.636,-75.965,8,m:eKnad2y

This can be used anywhere you have cell coverage, and can show the wind direction and velocity at any level you adjust it to.
Yup, I use it and love it. Indeed, my goal with an openrocket plugin would be to be able to plug in the data from windytv for wind at a few altitudes. Even better would be an automatic fetch, but I wouldn't even conceive of trying to implement that until I had a manually entered plugin working that I found useful.
 

ksaves2

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Kurt, not a slacker. Extremely challenged in terms of time. Somewhat challenged in close launch sites ( Bong Rec is home field, and I am particular as to what I will fly there versus weather/wind). A bit constrained on budget- I refuse to go into debt, or damage my family finances, for a hobby.
Just joking Mark. I'm in the same boat you are. Kurt
 

markkoelsch

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The RS I bought you can set wind speeds and thermals etc. Not sure if its pro, but I paid like $126 for it. Best money spent. It does just about everything
Pro is $1000. It does full six degree of freedom splash/landing patterns. It takes into account multiple wins layers at different directions and velocities. It takes all sort of variations into consideration.

Regular Rocksim not OR do this stuff.
 

ksaves2

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Kurt, I know you are joking. I also want to explain to those who do not know me.
Thanks. I don't ever want to be misconstrued as being insulting. Oh, I have no experience with RS Pro but can't it directly import online winds aloft
predictions and incorporate them pretty seamlessly with minimal fuss into the calculations? Kurt
 

markkoelsch

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Thanks. I don't ever want to be misconstrued as being insulting. Oh, I have no experience with RS Pro but can't it directly import online winds aloft
predictions and incorporate them pretty seamlessly with minimal fuss into the calculations? Kurt
You need to manually enter them. As I recall, you can then save the wind file for a given location.
 

rocketsam2016

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I've written a working OpenRocket extension that lets you set different wind speed/direction at different altitudes. It's not pretty but seems to work correctly and affect the various simulation plots in the way I'd expect (I can get the rocket ground track to go in circles during descent for example :) ). I'm using a very simple linear interpolation to calculate an average wind speed and direction given the rocket's altitude, that I then feed into a single instance of the pink noise wind model used by openrocket. This is certainly a poor approximation of actual wind layers, but I'm not sure that a more complicated modeling is useful given the imprecision of the data that one would feed into it. My first attempt used a pink noise model instance per input wind layer and interpolated between those models, but this had very weird behavior due to the underlying models sometimes jumping in opposite ways from each other as part of their independent pink noise processes.

I'll make it publicly available and link to it from this thread (along with the source code) once I'm more confident in it and have cleaned it up some, but if anyone is interested in trying out the rough version in the next few days then drop me a PM and I'll send it over once I've made a few final changes. I'd like to have a couple of people try it out before I share more broadly to avoid wasting a bunch of folks' time if there are dumb things I'm overlooking or ways it breaks or obvious feature additions.
 
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