[HOT] leisure=common (Helipad)
Project 892 task 23 is an example. The following question got sent to me probably because I've been validating merrily away. What is the minimum diameter for a Helipad (leisure=common)? Based on my own experience of visiting a remote Scottish Island the local football pitch, being smooth, level and firm enough was the designated helicopter landing place. I'm not sure that you can tell enough from satellite imagery that a certain bit of ground is smooth, level and firm enough to take the weight of a helicopter. However we seem to have a fair number of circular leisure=common areas tagged near fairly small villages. So can we flesh out a bit more of the requirements please and better identify what we should be looking for and mapping. Thanks John ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
Re: [HOT] leisure=common (Helipad)
Hi John, Our role is to grab information, facilitate the logistic of the humanitarian organizations. But we are not specialists. Once we have identified the common leisures, the GIS specialists from the international organizations can easily extract this info and examine further. Pierre De : john whelan jwhelan0...@gmail.com À : hot@openstreetmap.org hot@openstreetmap.org Envoyé le : Jeudi 19 février 2015 6h31 Objet : [HOT] leisure=common (Helipad) Project 892 task 23 is an example. The following question got sent to me probably because I've been validating merrily away. What is the minimum diameter for a Helipad (leisure=common)? Based on my own experience of visiting a remote Scottish Island the local football pitch, being smooth, level and firm enough was the designated helicopter landing place. I'm not sure that you can tell enough from satellite imagery that a certain bit of ground is smooth, level and firm enough to take the weight of a helicopter. However we seem to have a fair number of circular leisure=common areas tagged near fairly small villages. So can we flesh out a bit more of the requirements please and better identify what we should be looking for and mapping. Thanks John ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
Re: [HOT] leisure=common (Helipad)
Hi John, It is actually a quite difficult thing to specify because the performance of helicopters varies dramatically. To explain .. Temperature and altitude play a very large role, basically the higer you are, the thinner the air, the less bite on the rotors. There is a measure called density altitude, which is where the temperature comes in, the hotter it is, the thinner the air = same issue as above The combination of the two is one of the most important things a pilot looks at There are very few helicopters that routinely take off vertically, generally they will rise to a hover then move forward in ground effect (which is like a cushion of air between the rotors and the ground). This actually allows heavier helicopters to take off without needing so much power for a vertical climb out, and which many cannot do for performance reasons and options if they have an engine failure. Weight is another very critical factor, but that is an operational matter we will never know anything about and is often driven by temperature and altitude issues as well. So the bottom line is not so much the actual space, it is the approach and departure paths that are the most critical. Some choppers can come right in and drop and depart vertically, say into a foot ball field surrounded by a stadium. However, I know the pilots would much prefer to have options for approach and departure that gives them a way in and out without having to climb vertically, and probably means that they can carry more in terms of payload, people, etc. Again, this is all very much dependent on the type of helicopter, some can do it, others not depending on their performance envelopes. If we map the buildings around any marked landing areas, then any pilot will know immediately he is dealing with obstacles and can plan his flight accordingly. Height of those building is a VERY useful piece of information, but one we are unlikely to be able to provide from Sat images The other thing we can do is map power lines, other buildings, and groups of trees around the LZ's to show possible approach and departure paths, this would be very useful information for mission planners and pilots Hope that helps Regards Mark Cupitt If we change the world, let it bear the mark of our intelligence See me on Open StreetMap https://www.openstreetmap.org/user/Mark_Cupitt On Thu, Feb 19, 2015 at 7:31 PM, john whelan jwhelan0...@gmail.com wrote: Project 892 task 23 is an example. The following question got sent to me probably because I've been validating merrily away. What is the minimum diameter for a Helipad (leisure=common)? Based on my own experience of visiting a remote Scottish Island the local football pitch, being smooth, level and firm enough was the designated helicopter landing place. I'm not sure that you can tell enough from satellite imagery that a certain bit of ground is smooth, level and firm enough to take the weight of a helicopter. However we seem to have a fair number of circular leisure=common areas tagged near fairly small villages. So can we flesh out a bit more of the requirements please and better identify what we should be looking for and mapping. Thanks John ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
Re: [HOT] leisure=common (Helipad)
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 As Pierre has noted we map what is on the ground, not what how we think it should be mapped. If there is a common area then we tag it as such, if there is not then we should not 'invent' one that is close by simply for the purpose of having one. It is important to note, the reason I asked to have these mapped is that they _might_ be used as helipads, not that they must be. As Mark noted, the criteria for what is an acceptable landing site is something only a pilot can decide, and even then only for a specific helicopter and specific load. All we can do is tell them reasonable places to start looking, but it is for them to decide if any of the areas we marked are acceptable. I expect that they would try to review the area in imagery anyway or have someone confirm it on the ground before dispatching a helicopter there. Our data is not the final word, just something so that they have a starting place. As to the round areas, I have noticed several mappers doing this. Not sure if it is a newbie thing or what, but the area should not be mapped as round unless it is actually round. Otherwise we should be mapping the proper shape. - -AndrewBuck On 02/19/2015 08:16 AM, john whelan wrote: So the advice back to the mapper? My opinion would be if its readily identifiable as landuse=common then map it, but refrain from arbitrarily adding a circle tagged landuse=common close to each small village perhaps? Personally when I'm mapping if something like this stands out then it gets mapped but its quite rare that I spot one. Thanks Cheerio John On 19 February 2015 at 08:59, Pierre Béland pierz...@yahoo.fr wrote: Hi John, Our role is to grab information, facilitate the logistic of the humanitarian organizations. But we are not specialists. Once we have identified the common leisures, the GIS specialists from the international organizations can easily extract this info and examine further. Pierre -- *De :* john whelan jwhelan0...@gmail.com *À :* hot@openstreetmap.org hot@openstreetmap.org *Envoyé le :* Jeudi 19 février 2015 6h31 *Objet :* [HOT] leisure=common (Helipad) Project 892 task 23 is an example. The following question got sent to me probably because I've been validating merrily away. What is the minimum diameter for a Helipad (leisure=common)? Based on my own experience of visiting a remote Scottish Island the local football pitch, being smooth, level and firm enough was the designated helicopter landing place. I'm not sure that you can tell enough from satellite imagery that a certain bit of ground is smooth, level and firm enough to take the weight of a helicopter. However we seem to have a fair number of circular leisure=common areas tagged near fairly small villages. So can we flesh out a bit more of the requirements please and better identify what we should be looking for and mapping. Thanks John ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot -BEGIN PGP SIGNATURE- Version: GnuPG v1 iQIcBAEBAgAGBQJU5gDqAAoJEK7RwIfxHSXbCp8P/0o96GP1VYJ15SVRJUpBJW4f GNNHsTp4rckTb64/UWo/0i8J320Jigwi92pzvz9vmSbKOuSIp5DTNB0WqCLAlyWe FpGky+y24qtY3fj/mSDPNDVr0bpWGiSHgMGOWId9wCEM0Uv66rUS05UvpZuYvlws n9+GNxOrBMwJ6B1D8AKv4GGpmlTSjqfR6JUDn4m/TDj3dswNrtURfLqDvTVZJ5Z1 thWlClxahVj2HmdKDvVVkz5pcQswD16oq6mG9uBi8uG7OzWSu/Cqj73VxVLDYd0W B/I9U8aZ3bkTmYkz+achYaMa6AU/bUrDM1bNxl942NgcT3P0EzGN+zQoyoPam0wQ 2qLsacyw25Gkl/vSmVSE7K8nO1XLicwhOUvfY8GGwR5zC/pbsJ59Bl66ixeeRj7v MyNhZZzBrtxJPDKspqGfftUFW+V+b9JkXN/ZXd7LALEdxTi1rR76+jpROJ1JPeTB MVSMF9Hr82BPbCau0o1HT/qJkNXs9hQzm2Bo6LfC949w2xOZIJbPg1BoQYJDf4ck 8kfBZakTqiEeZB0VYN+8S3nbPUZLhf/1ZjbOF8zedSFEG/jRrE6SjV+DOORyn2VP KDzi1YV3xCjGzd+MONPfJHH67E/VNZRZJpXrqUAhzmTbemGHR6yGmh/EvCGbqFV8 KKAmi0BrSdYuiRxTT+OC =x08o -END PGP SIGNATURE- ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
Re: [HOT] leisure=common (Helipad)
So the advice back to the mapper? My opinion would be if its readily identifiable as landuse=common then map it, but refrain from arbitrarily adding a circle tagged landuse=common close to each small village perhaps? Personally when I'm mapping if something like this stands out then it gets mapped but its quite rare that I spot one. Thanks Cheerio John On 19 February 2015 at 08:59, Pierre Béland pierz...@yahoo.fr wrote: Hi John, Our role is to grab information, facilitate the logistic of the humanitarian organizations. But we are not specialists. Once we have identified the common leisures, the GIS specialists from the international organizations can easily extract this info and examine further. Pierre -- *De :* john whelan jwhelan0...@gmail.com *À :* hot@openstreetmap.org hot@openstreetmap.org *Envoyé le :* Jeudi 19 février 2015 6h31 *Objet :* [HOT] leisure=common (Helipad) Project 892 task 23 is an example. The following question got sent to me probably because I've been validating merrily away. What is the minimum diameter for a Helipad (leisure=common)? Based on my own experience of visiting a remote Scottish Island the local football pitch, being smooth, level and firm enough was the designated helicopter landing place. I'm not sure that you can tell enough from satellite imagery that a certain bit of ground is smooth, level and firm enough to take the weight of a helicopter. However we seem to have a fair number of circular leisure=common areas tagged near fairly small villages. So can we flesh out a bit more of the requirements please and better identify what we should be looking for and mapping. Thanks John ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
Re: [HOT] leisure=common (Helipad)
Yes, we simply map what we can identify as leisure=common. And has Mark said, it will help if we trace the buildings close to the field. Such data will be analyzed later by specialists. Our role is to provide them options that they will examine. Pierre De : john whelan jwhelan0...@gmail.com À : Pierre Béland pierz...@yahoo.fr Cc : hot@openstreetmap.org hot@openstreetmap.org Envoyé le : Jeudi 19 février 2015 9h16 Objet : Re: [HOT] leisure=common (Helipad) So the advice back to the mapper? My opinion would be if its readily identifiable as landuse=common then map it, but refrain from arbitrarily adding a circle tagged landuse=common close to each small village perhaps? Personally when I'm mapping if something like this stands out then it gets mapped but its quite rare that I spot one. Thanks Cheerio John On 19 February 2015 at 08:59, Pierre Béland pierz...@yahoo.fr wrote: Hi John, Our role is to grab information, facilitate the logistic of the humanitarian organizations. But we are not specialists. Once we have identified the common leisures, the GIS specialists from the international organizations can easily extract this info and examine further. Pierre De : john whelan jwhelan0...@gmail.com À : hot@openstreetmap.org hot@openstreetmap.org Envoyé le : Jeudi 19 février 2015 6h31 Objet : [HOT] leisure=common (Helipad) Project 892 task 23 is an example. The following question got sent to me probably because I've been validating merrily away. What is the minimum diameter for a Helipad (leisure=common)? Based on my own experience of visiting a remote Scottish Island the local football pitch, being smooth, level and firm enough was the designated helicopter landing place. I'm not sure that you can tell enough from satellite imagery that a certain bit of ground is smooth, level and firm enough to take the weight of a helicopter. However we seem to have a fair number of circular leisure=common areas tagged near fairly small villages. So can we flesh out a bit more of the requirements please and better identify what we should be looking for and mapping. Thanks John ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot ___ HOT mailing list HOT@openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
