| ??? 01/16/08 14:31 Modified: 01/16/08 14:34 Read: times |
#149560 - Answers to Cooper Responding to: ???'s previous message |
Thanks for helping me clarify
I sort of doubt if you need to get into spherical geometry. Here are some questions to help answer that question for sure:
What is the maximum distance from you to any one of the ten stationary objects? In other words, how far does the telemtry work? If you are only talking about short distances, then you can probably approximate the earth's surface as a plane. The telemetry works from 4-6 Km , the receiver has a Yagi. I take your point to approximate the earth as plane. Does that mean to use Pythagoras theorem?. How precisely do you know your position and that of the stationary objects? Unless you know them very precisely, any errors resulting from the assumption of a flat plane will be small compared to the uncertainty of the positions themselves. The accuracy level currently discussed is 15 meters without SA. Do you need to calculate the actual distances from you to the objects, o r do you (as you stated in your original post) only need to find the closest one? If you need actual distances, then you will have to translate your latitude and longitude coordinates into meters or kilometers or whatever, and that's slightly t ricky because a degree of latitude always represents the same distance, but degrees of longitude represent smaller and smaller distances as you move away from the equator in either direction. I feel I have to do that , and with every received coordinates , while my vehicle is moving . I would require to approximat which object I am just approaching and passing away from it and then I need to interrogate only that object which is closest via RF link. On the other hand, if you only need to find the closest object, and don't care how far you actually are from it, then you don't have to worry about any of that. Just pretend that a degree of latitude is the same as a degree of longitude and calculate the "distances" in terms of degrees. As for whether an 8-bitter can do this task, that depends mostly on how often you need to update your estimate of the closest object. I don't think you have mentioned that requirement yet. As Christoph mentioned, it really would help if you could give a complete description of the problem. Language problem , here I think I have written enough English , but maybe not enough :) . I would need to update every second my vehicle GPS coordinates , all other are stationary . I have said earlier , my vehicle is moving , it searches the telemetry and list the received coordinates. It then reads its own coordinates in real time , and it then has to calculate the approaching most nearby node the roadside out of all listed nodes. I feel I have explained my requirement here , if still I am not able to explain correctly please ask for clarification. Best/ AP Neil , the roads are 80- 100meter wide at most places and length is infinite all roads are interconnected :). |
