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).
Related
I've searched and can't find an answer to this question. I could write the code myself to do it, but I don't want to reinvent the wheel. :)
Since ZedGraph uses an IPointList and its indexer for internal data access, you can assign any kind of data structure to it and dynamically change the data that ZedGraph receives when it calls the indexer.
It's a smart architecture, and naturally, it would be feasible to implement a Level-of-Detail system using a custom IPointList where the number of points is culled based on the xScale and yScale of the GraphPane.
This way you can have millions of points loaded, but when the zoomlevel of the graph would show all the points, they can be culled so that ZedGraph is only drawing a few thousand. As the zoom magnification is increased, fewer points would be culled in the region of interest.
I wanted to know if ZedGraph already offers anything like this out of the box. I haven't seen any indication of support for it.
Does anyone know?
I posted about this on Sourceforge and got no response there either.
Then I posted on a fork on Github and got a response. It's here:
https://github.com/ZedGraph/ZedGraph/issues/13
The answer:
There is a naive algorithm that filters points by simply skipping them blindly to reach a target display number.
Of course this naive approach can give completely wrong impressions of what the data looks like when peaks and valleys get dropped in a line graph, for instance. IMHO, an algorithm like that is completely unuseable.
So basically, there is no acceptable built-in culling in ZedGraph at the present time.
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 working on a game which was developed by some other guy earlier. I am facing a problem that when player(with camera) start running on the road the buildings are not being shown up in their regular shape and as we move forward (more closer to the buildings) they gain their original shapes, and some times the buildings present on either side of the road are not visible by camera ( empty space ) and when we move closer to the building it comes up as visible object suddenly. I think it may be some unity3d setting problem (rendering , camera or quality). May be, it was being done due to increase performance on mobile devices.
can anybody know what may be the issue or how to resolve it.
Any help will be appreciated. Thanks in advance
This sounds like it's a problem with the available LODs for each building's 3D model.
Basically, 3d games work by having 2-3 different versions of each 3D model, with varying *L*evels *O*f *D*etail. So for example, if you have a house model which uses 500 polygons, you'll probably have another 2 versions (eg 250 polys and 100 polys), which are used depending on the distance between the player and the object. The farther away he is, the simpler the version used will be.
The issue occurs when developers use automatically generated LOD models, which will look distorted or won't appear at all. Unity probably auto generates them, but I'm unsure where you'll find the settings for this in unity. However I've seen 3d models on the unity store offering models with different LODs, so unity probably gives you the option to set your own. The simplest solution would be to increase the distance the LODs change at, while the complicated solution would be to fix custom versions of the 3D models for larger distances, with a lower poly count.
I have resolved the problem. This was due to the LOD (level of details) used for objects (buildings) in Unity3d to enhance the performance on the slower device. LOD provides many level of details (of an object) which you can adjust according to your need . In my specific problem the buildings were suddenly appear due to the different (wrong) position for LOD1, i.e. for LOD1 the building was at wrong place but for LOD0 it was at its right place. So when my camera see from the distance it see LOD1 which was at wrong place thence it sees empty space with no building at the expected position. But when camera comes closer it sees LOD0 in which building is at the right position and it seems that buildings are suddenly come or become visible.
Hi there
I am using location manager and mapkit, i am able to get the curernt location, but its not accurate enough - This is my problem
My current location on the map is for example 3.0856333888778926, 101.67204022407532, but location manager's location only returns +3.08370327, +101.67506444; which is short of a few decimal numbers
This is resulting in the wrong location (about 1 KM away) when i try to show directions
I have already set location to be kCLLocationAccuracyBest -
Any suggestions?
Where do you try it? Inside, the accuracy of GPS is inherently limited (usually not to 1km, though. But within big cities, reflections from buildings are possible). Ahh, and another thing: is the measurement done inside the simulator? I'm not sure how the location is determined within it. But in my tests, I'm also usually quite off my actual position.
It may be related on how you have setup your locationmanager.
Could you please post it here for us to check? Maybe this could help.
Are you on wifi? This happens to me if I am on wifi. When I switch to edge/3g, everything turns to normal. Just try with standard map application if it also shows you wrong.
the highest possible accuracy and combine it with additional sensor data.
kCLLocationAccuracyBestForNavigation
This level of accuracy is intended for use in navigation applications that require precise position information at all times and are intended to be used only while the device is plugged in.
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.