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On Thursday, September 20, 2012 7:35:02 PM UTC-5, Eric Greenwell wrote:
On 9/20/2012 9:25 AM, Steve Leonard wrote: My biggest interest is in temperature versus altitude in the first 1KM to 1.5KM above the surface. This will let you know where the cap that might kill the day exists. I had started a project for this some years ago, and since the wind usually blows here in Kansas, I was looking to use a couple of kites to lift the package. It would always stay within the confines of the airport, and would have much lower recurring cost than a helium balloon. I would be intereted in a package that gets temperature and altitude either logged on board, or transmitted to a PC on the ground. And at $150 or so, I am very interested. Have you found the NWS lapse rate forecasts inadequate? http://rucsoundings.noaa.gov/ -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) Usually the soundings there are pretty good but we've also gone through spells where we had inversions that the models just weren't catching. Sometimes this has gone on for weeks, like for 2 or 3 weeks last June when the models were all predicting great soaring when in fact there was a hard inversion at about 5000 MSL and it totally sucked. I think there is some real benefit to having actual measured real life data instead of a computer model. At 150 per unit, especially if you can reliably retrieve the transmitter, I think it would be worth it. |
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On 9/21/2012 2:22 PM, Tony wrote:
On Thursday, September 20, 2012 7:35:02 PM UTC-5, Eric Greenwell Have you found the NWS lapse rate forecasts inadequate? http://rucsoundings.noaa.gov/ -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) Usually the soundings there are pretty good but we've also gone through spells where we had inversions that the models just weren't catching. Sometimes this has gone on for weeks, like for 2 or 3 weeks last June when the models were all predicting great soaring when in fact there was a hard inversion at about 5000 MSL and it totally sucked. I think there is some real benefit to having actual measured real life data instead of a computer model. At 150 per unit, especially if you can reliably retrieve the transmitter, I think it would be worth it. Maybe you could talk an ultralight pilot into doing it for the gas money. They like to fly in the morning anyway, and having a mission would delight the ones I know. There are $60-$100 USB temperature and humidity recorders that could easily carried (a few oz.), downloaded to a PC after landing, then the file emailed to you. Here are some examples: http://www.thermoworks.com/products/...b_loggers.html The trick is selecting one with a proper response time to get an OK lapse rate. The one I have is about a minute - too slow for a climbing aircraft measurement - but I saw one of 20 seconds (probably OK for a 500fpm climb rate). That would give a decent lapse rate. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) |
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On Friday, September 21, 2012 6:11:53 PM UTC-4, Eric Greenwell wrote:
There are $60-$100 USB temperature and humidity recorders that could easily carried (a few oz.), downloaded to a PC after landing, then the file emailed to you. Here are some examples: http://www.thermoworks.com/products/...b_loggers.html The trick is selecting one with a proper response time to get an OK lapse rate. The one I have is about a minute - too slow for a climbing aircraft measurement - but I saw one of 20 seconds (probably OK for a 500fpm climb rate). That would give a decent lapse rate. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) Interesting. Aside from the morning sounding, it would be very interesting to gather data for after-the-fact comparison of model forecast sounding vs.. actual. These don't look perfect (the accuracy is a little coarser than I'd like), but I could see fixing one of these under the wing of our club Grob and doing some interesting studies. My suspicion is that many of the misses where we are (NJ/PA area) have less to do with the basic atmospheric lapse rate and more to do with getting the surface dewpoints and amount of surface heating wrong, but this would be a good way to test that out. |
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As Tony said, we can have really inacurate forecasts here. Mainly because our closest sounding sites are either the other side of the Marfa Dry Line, far enough upwind that even though there are no obvious airmass boundaries, the airmass is definitely different (look at OLC posts from Hinton, OK versus Sunflower on 7-20-2012), or far downwind into the armpit of the soaring world (Topeka, KS). A local sounding is really needed to know what might happen.
As for hiring an ultralight, that would probably cost at least as much each time as a helium balloon. And remember. We are in Kansas. The reason I was thinking of using kites is because the wind blows. Lots. And many days, the ultralight pilot will either not be available or willing to go. I have a couple of hundred dollars worth of kites and high strength line. Now, I just need a small data package to put onboard! Those are neat loggers, but I didn't see one that measures pressure (altitude). Without that, you have nothing. What we are really looking for is "will it go to at least 3000?" The day's Tony mentioned were 5000 MSL, or 3500 AGL. With a saounding to even 3000, we would know what we would be up against. I sense the technology is available now, but maybe just not for a mass market. Hoping Andres is still watching this thread. Steve |
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On 9/23/2012 7:43 PM, Steve Leonard wrote:
As Tony said, we can have really inacurate forecasts here. Mainly because our closest sounding sites are either the other side of the Marfa Dry Line, far enough upwind that even though there are no obvious airmass boundaries, the airmass is definitely different (look at OLC posts from Hinton, OK versus Sunflower on 7-20-2012), or far downwind into the armpit of the soaring world (Topeka, KS). A local sounding is really needed to know what might happen. As for hiring an ultralight, that would probably cost at least as much each time as a helium balloon. And remember. We are in Kansas. The reason I was thinking of using kites is because the wind blows. Lots. And many days, the ultralight pilot will either not be available or willing to go. I have a couple of hundred dollars worth of kites and high strength line. Now, I just need a small data package to put onboard! Those are neat loggers, but I didn't see one that measures pressure (altitude). Without that, you have nothing. What we are really looking for is "will it go to at least 3000?" The day's Tony mentioned were 5000 MSL, or 3500 AGL. With a saounding to even 3000, we would know what we would be up against. Here's one that's not as convenient, perhaps, but does measure altitude and temperature, plus GPS and more if you want it. $70 logger $38 20k altimeter sensor $11 temperature sensor http://www.eagletreesystems.com/MicroPower/micro.htm The model rocket people have this kind of stuff, and a 3000 agl rocket might be a cheap and reliable way to put the instruments up where you want them. Retrieving in a wind would involve a chase, but they also have locators of various types to help find it. There is likely a model rocket society somewhere near you that could help. Here is a rocket logger: altitude, temperature - $80 http://www.perfectflite.com/sl100.html It has two chute deployment altitudes - small chute at the top of the launch, bigger one near the ground, so drift is minimized. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) |
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On Monday, September 24, 2012 12:10:39 AM UTC-5, Eric Greenwell wrote:
Here is a rocket logger: altitude, temperature - $80 http://www.perfectflite.com/sl100.html May have to get one of those. But again rockets are not the way to go for recurring cost. As I recall from talking with one of our local rocket guys, they are $30 and up per shot. Don't mind a few more bucks to get started, but hate recurring costs. Thanks for the searching, Eric. If I get one, I will let you know how the kite flying and data collecting goes. That one might have issues, as the launch, climb, and recovery of the kite will likely be more than 9 minutes. Reeling in 7000 feet of like takes a bit of time! Steve |
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Steve,
Would XCSkies work for your needs? I see, looking at the map for Hutchinson, that you should be getting lift up to 2,000' AGL right now! "Steve Leonard" wrote in message ... On Monday, September 24, 2012 12:10:39 AM UTC-5, Eric Greenwell wrote: Here is a rocket logger: altitude, temperature - $80 http://www.perfectflite.com/sl100.html May have to get one of those. But again rockets are not the way to go for recurring cost. As I recall from talking with one of our local rocket guys, they are $30 and up per shot. Don't mind a few more bucks to get started, but hate recurring costs. Thanks for the searching, Eric. If I get one, I will let you know how the kite flying and data collecting goes. That one might have issues, as the launch, climb, and recovery of the kite will likely be more than 9 minutes. Reeling in 7000 feet of like takes a bit of time! Steve |
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On Monday, September 24, 2012 11:48:37 AM UTC-5, Dan Marotta wrote:
Steve, Would XCSkies work for your needs? I see, looking at the map for Hutchinson, that you should be getting lift up to 2,000' AGL right now! "Steve Leonard" wrote in message ... On Monday, September 24, 2012 12:10:39 AM UTC-5, Eric Greenwell wrote: Here is a rocket logger: altitude, temperature - $80 http://www.perfectflite.com/sl100.html May have to get one of those. But again rockets are not the way to go for recurring cost. As I recall from talking with one of our local rocket guys, they are $30 and up per shot. Don't mind a few more bucks to get started, but hate recurring costs. Thanks for the searching, Eric. If I get one, I will let you know how the kite flying and data collecting goes. That one might have issues, as the launch, climb, and recovery of the kite will likely be more than 9 minutes. Reeling in 7000 feet of like takes a bit of time! Steve xcskies is still a model based forecast. when the model is broken it doesn't matter if dr. jack or xcskies is interpreting the data it still will be wrong. |
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On 9/24/2012 6:25 AM, Steve Leonard wrote:
On Monday, September 24, 2012 12:10:39 AM UTC-5, Eric Greenwell wrote: Here is a rocket logger: altitude, temperature - $80 http://www.perfectflite.com/sl100.html May have to get one of those. But again rockets are not the way to go for recurring cost. As I recall from talking with one of our local rocket guys, they are $30 and up per shot. Don't mind a few more bucks to get started, but hate recurring costs. Thanks for the searching, Eric. If I get one, I will let you know how the kite flying and data collecting goes. That one might have issues, as the launch, climb, and recovery of the kite will likely be more than 9 minutes. Reeling in 7000 feet of like takes a bit of time! Maybe use the old kite flyers trick of sending the instrument pack up the string in a little pod with a sail, once the kite is at altitude. Or, reverse it: have the pod slide down the string from the kite after it's up, and have even quicker access to the data. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) |
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On Monday, September 24, 2012 12:00:59 PM UTC-5, Eric Greenwell wrote:
Maybe use the old kite flyers trick of sending the instrument pack up the string in a little pod with a sail, once the kite is at altitude. Or, reverse it: have the pod slide down the string from the kite after it's up, and have even quicker access to the data. -- Eric Greenwell Well, the package would have to be on the second kite in my system. It seems that one kite on 1000 feet of string got to about 800 feet based on the altimeter watch that was used in initial testing. Adding another 1000 feet of string only got about 400 feet more altitude. Bigger kite needed. But, what to do with the smaller one, since the money was invested? Tie it to the main line on a 100 or so foot tether, and let it help in lifting the line. So, I won't have a 7000 foot long, clear shot up the line. I did learn some interesting dynamics of an intermediate, line lifting kite, though. Interested in seeing the dynamic of a powered winch to reel the line in. Will have the effect of increased wind speed for the kites, so they should climb a little higher. First attempts were with people grabbing the line and walking it towards the reel (yes, the first 200 feet or so of the line was only 4-6 feet off the ground when we had, I believe, 3000 feet of line). I have seen what this line put on a Home Depot Extension cord reel does over time. I now have a big mess of kite string, as it contracted and split the ends off of the reel! Steve |
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