{"action":"created","issue":{"url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech/issues/706","repository_url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech","labels_url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech/issues/706/labels{/name}","comments_url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech/issues/706/comments","events_url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech/issues/706/events","html_url":"https://github.com/RemoteTechnologiesGroup/RemoteTech/issues/706","id":191889517,"number":706,"title":"Noise background to affect communications link range","user":{"login":"diomedea","id":6025911,"avatar_url":"https://avatars.githubusercontent.com/u/6025911?v=3","gravatar_id":"","url":"https://api.github.com/users/diomedea","html_url":"https://github.com/diomedea","followers_url":"https://api.github.com/users/diomedea/followers","following_url":"https://api.github.com/users/diomedea/following{/other_user}","gists_url":"https://api.github.com/users/diomedea/gists{/gist_id}","starred_url":"https://api.github.com/users/diomedea/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/diomedea/subscriptions","organizations_url":"https://api.github.com/users/diomedea/orgs","repos_url":"https://api.github.com/users/diomedea/repos","events_url":"https://api.github.com/users/diomedea/events{/privacy}","received_events_url":"https://api.github.com/users/diomedea/received_events","type":"User","site_admin":false},"labels":[{"id":102151296,"url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech/labels/Feature%20Request","name":"Feature Request","color":"84b6eb","default":false}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":1,"created_at":"2016-11-27T22:16:11Z","updated_at":"2016-11-28T10:58:25Z","closed_at":null,"body":"Range in communications is customarily computed using the [Friis equation](https://en.wikipedia.org/wiki/Friis_transmission_equation), and RT does quite in a good way too, at least when adopting the root model. Sure enough, polarization (with both transmitting and receiving antennae) isn't included, and reflection is \"cumulated\" with gain. But those simplifications don't really affect realism much.\r\n\r\nOne major factor isn't however factored in, and it much more affects realism. With the Friis equation, we compute the Pr (received power) at the receiving antenna. There is no consideration about the [noise power](https://en.wikipedia.org/wiki/Noise_(radio)) that same receiving antenna is catching. A receiver can generally make apart signal from noise, up to a limit when the signal to noise ratio (S/N) remains greater than 1. That means, in real communications, received noise needs be reduced with all possible means (limited receiver bandwidth, very high frequency selectivity, very high antenna gain). Deep space communications need to use such techniques to the extreme (e.g., internal receiver noise is contained by low circuitry temperature). One factor however remains: the effective average noise power from the specific direction the receiving antenna is facing. When pointing towards an object in deep space, received noise is as low as the [cosmic background noise](https://en.wikipedia.org/wiki/Cosmic_microwave_background). Having the antenna aiming a near body, brings the thermal radiation from that body as additional noise (at the specific frequency the receiver is tuned to). Of course, inhabited bodies like Earth add a whole world of background noise from human presence. But the real problem is when Sun enters the equation: its thermal noise is many times higher than signal from a distant vessel. The aiming direction and directivity of the receiving antenna are crucial to keep received noise low, so a choice with a very high gain antenna and very high frequency (that helps with reducing both size of the antenna, and the relative percentage of received noise from the whole radiation spectrum according to [Wien](https://en.wikipedia.org/wiki/Wien%27s_displacement_law)). \r\n\r\nSorry for the length of the explanation above, back to RT. It would be great to have the average background noise in the direction aimed by the receiving antenna modelled. Therefore, when e.g. Sun is close in angles to the direction of the transmitter (seen from the receiving antenna), its thermal noise enters the equation causing a reduction in range. Main factors are frequency used, distance from Sun, and angular difference against antenna gain. \r\nOf course computing noise level would have some weight on performance, and some players would prefer not to deal with it. Playability against realism, as often there's a choice to be made. I'd leave players the ability to choose with a RT setting, if they want one or the other. \r\n"},"comment":{"url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech/issues/comments/263242450","html_url":"https://github.com/RemoteTechnologiesGroup/RemoteTech/issues/706#issuecomment-263242450","issue_url":"https://api.github.com/repos/RemoteTechnologiesGroup/RemoteTech/issues/706","id":263242450,"user":{"login":"diomedea","id":6025911,"avatar_url":"https://avatars.githubusercontent.com/u/6025911?v=3","gravatar_id":"","url":"https://api.github.com/users/diomedea","html_url":"https://github.com/diomedea","followers_url":"https://api.github.com/users/diomedea/followers","following_url":"https://api.github.com/users/diomedea/following{/other_user}","gists_url":"https://api.github.com/users/diomedea/gists{/gist_id}","starred_url":"https://api.github.com/users/diomedea/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/diomedea/subscriptions","organizations_url":"https://api.github.com/users/diomedea/orgs","repos_url":"https://api.github.com/users/diomedea/repos","events_url":"https://api.github.com/users/diomedea/events{/privacy}","received_events_url":"https://api.github.com/users/diomedea/received_events","type":"User","site_admin":false},"created_at":"2016-11-28T10:58:25Z","updated_at":"2016-11-28T10:58:25Z","body":"Thank you for the kind reply. \r\nIndeed, frequency (and selectivity of the receiver) are important in the real world equation to model this feature; therefore it would appear the more realistic when RT also has frequency implemented. However that isn't mandatory, could well be possible to use an average of noise in the whole spectrum used for communications, so to skip frequency as a factor.\r\nTotally concur this feature could require quite a deal of research. If there was a commitment by the RT group towards implementing this feature, I'll gladly share the burden with more research and data on the subject. Fine if it comes after current work is done, understand RT 2.0 is planned with other more pressing features in mind."}}
{"actor":{"display_login":"diomedea"}}