Lets's imagine this. I have tracking devices sending their coordinates. I have a GPX and the map. Now, between point one and two (blue circle from bottom to top) the GPX have no points. The tracker reports his location, but is not tottally align with the line because of weak GPS signal or anything else. I want to align the marker in the GPX line even with no points.
Can i do it? Can you help guys? All comunication and service are in PHP
This is not a trivial problem but you should be able to solve it by utilizing some premade services. This post on GIS StackExchange lists some services that can do this.
Related
I'm working on a compass app and need to find current direction to a particular point (I have coordinates), or at least to the north. How can I do that?
Thanks.
For those who faced the same problem:
1) get access to magnetometer and accelerometer of a device. For that you can either write your own react-native <-> java/swift/objC bridge or use one of libraries like these:
github com/pwmckenna/react-native-motion-manager
github com/kprimice/react-native-sensor-manager
2) convert meters' data to compass heading.
Some informations is here:
https://cdn-shop.adafruit.com/datasheets/AN203_Compass_Heading_Using_Magnetometers.pdf
3) If there is a need to find direction to some particular point, first you need to get your own coordinates and then adding that to point's coordinates you can find out azimuth.
It does not support, but you can simply render a polyline annotation from your direction result.
Currently I manage to get the direction degrees using below code:
d = Math.Atan2(Math.Sin(long2 - long1) * Math.Cos(lat2), _
Math.Cos(lat1) * Math.Sin(lat2) - Math.Sin(lat1) * Math.Cos(lat2) * Math.Cos(long2 - long1))
Dim direction As Double = (RadToDeg(d) + 360.0) Mod 360
which, in my case let say I got 250.65°
I assign each of the direction values from 0 to 360 to its particular image from imageList which loaded in the pictureBox. (currently I have 36 compass images with different arrow direction, each represent 10 degrees)
When my device is pointed to the north, the arrow image is showing the correct direction, but when when I rotate the device (pointed to anywhere which is not north), the arrow image doesn't change, means it is not showing the correct direction anymore.
So my question is, is it possible to know in which direction the gps device is pointed?
Edit: I'm using Honeywell Dolphin 6000 Scanphone device
The Honeywell Dolphin 6000 documentation doesn't mention a magnetometer or compass, so you're probably SOL. But, if it does have one, then you should be able to find methods to access it in the SDK
I recommend downloading and reviewing any APIs and documents that come with the SDK and look for references to the magnetometer or compass. Microsoft does not have standard APIs to access those sensors in Windows Mobile, so you will need the SDK from Honeywell to get that information.
If I am reading your question correct, it sounds like you are trying to determine a heading when your position is fixed and you are only rotating the device.
Unfortunately, what you are looking for is not possible with GPS.
Both the formula you are using and the GetPosition.Heading is a calculated heading based on sampling your current Latitude/Longitude and your previous Latitude/Longitude. So if you aren't moving in a direction (or moving extremely slowly), your current & previous Latitude/Longitude values will effectively be the same, which reduces that accuracy of the calculated heading.
The only reliable way to get a heading when your position is relatively fixed is to get a magnetic or gyroscopic compass, which some devices to have built in.
"how to know gps device point at which direction?"
by using GPS Intermediate Driver, GetPosition.Heading will give you the current direction you are heading.
As stated in the GPS_POSITION documentation,
"flHeading
"Heading, in degrees. A heading of zero is true north."
You must distinguish between the direction you are moving, that is called bearing or course.
And the direction you are looking or holding your device. (Think of you sitting in a bus that drives north (course = 0°), where you make a photo in direction west. heading = 270°)
A (consumer-) GPS receiver always returns only the course (or bearing), although some API unfortunatley call it heading sometimes.
To know the direction in wich you are holding your device while standing still, you have to use the magnetometer. Some modern smartphones, like iPhones or androids have that build into.
Additonal hint:
If your device has GPS, do NOT calculate the position via your or other formulas, better take the value from the GPS Api. This is much more acurate. The GPS chip does NOT only caluclate the direction by positional change, it also may use physical doppler shift.
Why should you ever want something like this?
I want to track a single user that is mounted above the ground in a horizontal position. The user is facing downwards to allow free movement of legs and arms. Think of swimming for example.
I mounted the Kinect at the ceiling facing downwards so I have a free view of all extremities.
The sensor is rotated 90° in z-axis to have the maximum resolution (you're usually taller than wide).
Therefore the user is seen from the backside, rotated by 90°. It is impossible to get a proper skeleton from OpenNI 1.5. My tests showed that OpenNI is expecting the user facing the camera with the head up in y-axis (see my other answer). Microsofts SDK is the same but I excluded it here because it won't allow you to change the source code and cannot be adapted. OpenNI 2.0 is not working with the current SensorKinect to interface the Kinect in Linux. So:
Which class is generating the skeleton in OpenNI 1.5.x?
My best guess would be to rotate the prototype skeleton by y 180° and z 90°. If you know where I could find this.
EDIT: As I just learned there is no open source software that generates a skeleton from depth images so I fall back to the question in the header:
How can I get a user skeleton from a rotated back view?
I'm creating a simple Map application in Titanium Appcelerator, right now focusing only on iOS. I have 2 Annotations specified by the latitude and longitude. I want to draw the directions between the 2 points on the Map.
I see the
mapview.addRoute();
method on the MapView object, but it requires you to input all the points in the route to draw it properly?! That doesn't sound right at all - why would it require me to find all the points when the Google Map can do that already.
Is there a way that I'm missing to simply say "here's point A, here's point B, draw the route between the 2 points on the map".
Drawing routes on the map is nothing more than a vector drawing. The same does the mapsapp on your phone.
You will have to interrogate the maps apis for directions,get the directions (points) and use it in your code to draw the route.
If you don't want to do it yourself there is a free module in the marketplace that can help
https://marketplace.appcelerator.com/apps/2580?87150712
If you want to get your hands dirty, this post might help you:
http://developer.appcelerator.com/question/74221/mobile-map-route-from-google-server
I'm completely new to ArcGIS and ArcMap, but someone suggested this program to me for a project I'm working on.
I would like to animate individual entities on a map, and was wondering if it is possible to do so in ArcMap. I asked this earlier here and a member directed me to a tutorial on animating in ArcGIS. The animation in the guide was over a map spread (ie. each pixel on the map displays, say, a different color to indicate population data in the area). However I realized that if I zoom in a lot, eventually the image will degenerate into pixels, which is why I need an actual object to mark a certain point. I checked some online tutorials and it seems like we can place markers on the map. Can someone tell me if it is possible to animate these markers (for example via a for-loop)? And if so, could you point me in a direction where to start?
Thanks in advance!
You can animate layers in ArcMap is the short answer. Its not as simple as using the timeline feature in Google Earth for example though. But then ArcMap is much more than just a visualization tool.
This help page on the ESRI web help looks like a good place to start.
I'm not 100% sure what you mean by the image degenerates into pixels. Are you saying that the markers were single points in the layer. Unlike Google Earth you are not confined to simply plotting points on the map. You can draw completely arbitrary shapes in ArcMap, which can be defined to cover actual areas of the map, so when you zoom-in the shape gets larger.
The way you need to load data into ArcMap to produce an animation isn't too simple. There might be other ways to do this, but the way I know of is to generate a NetCDF file. This file contains a 3D matrix of layer data, where each layer is separated through time. Because you generate a matrix, you are effectively placing a raster image over the map. Thus if you want to cover a large area, each matrix becomes large, and you multiply that by the number of time slices you wish to animate over.
Once you have a NetCDF file with your data in however, getting ArcMap to animate it and produce say a .avi file is pretty simple.
You could try just loading some of the example NetCDF datasets into ArcMap to see how/if they will work to get you started.
Hope that helps.
The upcoming v10 will have better time-aware capabilities, which will allow for animation.