Hello due to reasons of chinese paranoia and google being a bunch of pansies I am in the situation where I need to alter a number of gps waypoints stored in a gpx file so they are are correctly aligned with google map which is not correctly aligned... for reasons for aforementioned paranoia.
So I have a waypoint with a known landmark (railyway station) I can see that landmark on the google map, I would like to be able to move the waypoint in my gpx file to the new the one on the map and have all the other waypoints adjust accordingly.
This could be achieved by creating a new waypoint over the station on the map and calculating and then applying the difference or with some kind of GUI drag and drop.
I have no idea how to go about this and wonder if anyone knows of a decent solution other than persuading google to stop being pansies....
Of course google could change their magic misalignment randomly and then I'm truely screwed but hey ho.
Well you could build a small web app that takes your GPX track and overlays it on google maps. Then write some code to let the user enter some number of "corrected pairs" where they click on the GPX point and then the point on google maps. Once they have done this for n number of points, where n is the number of points you want to achieve accuracy, you can calculate an average errorX and errorY. Then you can go about and for each GPX point do X + errorX and Y + errorY which should be good on average.
Does that make sense?
Thanks for the reply TheSteveO I'd forgotten about this, in the end I used the rather handy javascript library provided here
http://www.movable-type.co.uk/scripts/latlong.html
To build myself a simple command line script which loads and realigns all the coordinates based on, as you suggested the difference between a known point on google maps and a waypoint of the same place.
I did attempt to implement it in php but unfortunately ran into a slew of floating point math problems and being pressed for time just went the javascript route.
Related
I'm a complete newbie in this matter so please ... be patient!
I have a similar (though more complex, I believe) problem to this (Save data from ArcGIS feature layer) with the comprehensive answer by AaronS.
I thank in advance whoever might be supportive.
My goal is to retrieve (via time based script) data for real time processing from a meteo website (https://www.meteo3r.it/app/public/) based on ArcGIS. In particular, I need two types of data:
A) the most updated values of all measurements available IN A GIVEN METEO STATION (or ALL, then I will filter out)
B) two pixels maps with the radar measurement of rain intensity AND type of fall (rain, heavy rain, snow, hailstorm, ...) FOR ALL AVAILABLE GEOGRAPHICAL COORDINATES
Type A) Data seems available every 30' with a 1h delay while type B) seems more frequent with a 5' sample and 10' delay. Everyone agrees ?
For sure I will benefit of the python code (thank you Aaron again!) to turn data into column vectors as soon as I will be able to retrieve data from the server. And that's exactly the point I'm stuck at.
For A), thanks to Aaron explanation, I found this URL (https://www.meteo3r.it/dati/mappe/misure.geojson) that contains all the measurements for ALL stations at, I believe, the most updated value in time.
B) is definitevely tougher. I can't find anywhere the place where the radar data is stored and how to retrieve it. The only thing I found is that if you search for the word "radar" as Aaron did for "14001", the only file found is this "66xxx.pbf". It's a partially readable binary file that I suspect (not fore sure) is related to sprite images (pixel drawings) that are graphically showing the radar measurement on the map.
Indeed, the website shows something like 10 subsequent sprite images to show a "dynamic motion" of the clouds.
I just need the data in numerical form (lat, long, intensity, type) related to the most updated sprite available on the website.
Anyone knowing how to do it ?
Thanks a lot removing this roadblock to me.
I'm currently using Google Earth + KML Files to visualize Aircraft Flightpaths in 3d, it works perfect and also looks fine, but the big disadvantage is, that there seems to be no way to feed "live" data to Google Earth and draw the Flightpaths in Realtime.
Is there an alternative that is capable to display live data without manually reloading a file or anything like this? Satellite Picture surface would be an absolute MUST.
Maybe someone out there knows a proper solution for my project.
Thanks
The KML NetworkLink tag provides several ways to automatically update/reload a KML file, which will let you provide "live" data. You can either make the NetworkLink update the KML every time the user stops moving the map (with a setable delay), or on a timer (eg: every 10 seconds). Look at the KML Reference and developer tutorials for more info.
I am currently developing technique to help users find a spot to park.
But i face a little problem:
if a user indicates that he is parking right now in a free spot but he is lying and he is at home right now.
How can i detect from GPS if he is inside a building or along side the road?
Thanks
You'll need map data (OpenStreetMap is free), and figure out whether the user is somewhere on that map or not. You do that by comparing GPS data to the map data.
What I do in such situations is measure the distance between the lat/lon and each road, and compare the GPS angle to that of each line. The more context information you use the more accurate you can get your results:
If the speed is 60km/h, you're probably not in a building. You're probably not on a 30km/h road either.
If you're standing still for more than 2 minutes, you're probably not in a car.
If you know the buildings, and there are only a few of them, you could check if you see a certain wifi router or not.
Basically you'll calculate a score for each road, and then pick the road with the highest score to know where you are.
Score = DistScore*DistWeight + AngleScore+AngleWeight etc.
Also, from iOS and Android you get an accuracy in meters. You can also calculate that yourself if you can access raw GPS data. Using that, you set the area that you need to scan. For example, for a high accuracy (3m), you probably don't have many roads to scan. If the accuracy is 50m, you should probably match roads that are farther away.
If accuracy is important, you should look at series of GPS data, and test if the followed route is a logical path or not.
I am trying to get indoor gps by trying to orient my floorplan with the actual building from google maps. I know perfect accuracy is not possible. Any idea how to do this ? Do the maps need to be converted to kml format?
Forget that!
Only with luck you can get indoor GPS signals, probably only near the window, and then it is likely to be more distorted than the size of your building.
You only can try to get the coordinates outside, at the corner of the buildings.
For precise measures you would need some averaging of the measures, which only a few GPS devices offer. For less precision, take the coordinate, or measure it on differnet hours, days.
Otherwise, you should think about geolocation using Wifi/HF and any other wireless/radio sources that you can precisely locate since you probably install it yourself or at least someone from your company/service is responsible of them and could give you the complete list with coordinates. Then, once you've got the radio location, you can geolocate the devices using radio propagation and location.
I know that's not the answer you were looking for, but think about it as an alternate one if you really need to locate people inside your building.
PS: I did it at work and it works pretty well (except some areas where radio emitter are broken).
My name is John and I am a grad student at the University of Florida. As part of my research one of my tasks is to create a piece of software that is to display a map of the surrounding area, which shows the current location (from a GPS), and to implement a shapefile (as a boundary outline). I am not able to really get enough information to get on the right track on how to do this, and would appreciate any assistance!
The project involves a large-scale robot that will be operated by tele-communication in rough terrain. So this mapping and gps software will need to be entirely offline, but the location in use will be known. It is very preferred to find a cost effective means to doing this process (maybe even a simple API that could do the simple task, dll libraries, or active x.
My initial guess is to use a geo-referenced image (that I would get the lat and long of and know the boundaries of that image). Then from a GPS I then would treat the image as an XY plot somehow and that would provide the current position. Obviously even this step can be a challenge depending on what kind of image, map, kml file, etc that I can find and use.
So I would appreciate any advice, suggestions, or comments.
Suggest you online reference source code, and then modify their own, this project is currently on the Internet, you can through search engines to find. Good luck!