I am grabbing maps from bing using their API:
http://msdn.microsoft.com/en-us/library/ff701724.aspx
The largest tile they can return is 900x834. I need at least double that. Is there an easy way to figure out what the adjacent tiles are for any given zoom level and long/lat for a given resolution.
In other words, given a long,lat, zoom level, and resolution what would be the long lat for the 8 surrounding tiles in the same zoom level and resolution. Or is there a better way to get a large map?
Here's my GET request:
http://dev.virtualearth.net/REST/v1/Imagery/Map/Aerial/#{lat},#{long}/#{rand(19)}?mapSize=900,834&format=png&key=MYKEY
It is not possible to do this without breaking the rules set in the Terms of Use, especially the automation regarding your imagery retrieval (or composition).
See: http://www.microsoft.com/maps/product/terms.html
If you want to do this anyway with maybe a dedicated agreement to proceed (if possible), I would recommend to use mapArea parameters rather than using the lat long of the center, see:
http://msdn.microsoft.com/en-us/library/ff701724.aspx
See an example of mapArea imagery retrieval:
http://dev.virtualearth.net/REST/V1/Imagery/Map/road?mapArea=37.317227,-122.318439,37.939081,-122.194565&ms=500,600&pp=37.869505,-122.2705;35;BK&pp=37.428175,-122.169680;;ST&ml=TrafficFlow&key=BingMapsKey
If you want to access tile url in a supported way, you can use the same imagery service to retrieve metadata that will contain tile url. Tile are based on a quadkey model so you will be able to load the tile nearby your current view.
Related
Given a bound box like the below picture, how do you get all the features contained within, regardless of if they are visible or not.
I have tried to get all roads using
let features = map.querySourceFeatures('composite', {sourceLayer: 'road'})
But it only gives me roads that are visible if I am zoomed in.
I have also tried
let features = map.queryRenderedFeatures([tile_info.swPt, tile_info.nePt])
But again, it only gets features visible on the map based on zoom level.
I need all the features within the bounding box regardless of what you can see or zoom level
It is in the nature of vector tiles that you can not do what you want to do here. You can only query data which has been loaded into the browser, and the point of the vector tile architecture is to prevent that happening at lower zooms.
You could consider a server based approach like Tilequery.
I need a framework which takes a set of latitude longitude points and plots on a world map, grouped by country having the count of points as a marker on each country. Grouping here is the count of latitude longitude points in a country.
And as I drill down into a country, the clustering should change to state based one. And the next level, to districts.
Leaflet marker cluster is something very similar to what I have asked for, but the grouping is based on proximity and it doesn't consider country or state boundaries. That is, they are not region aware.
Regionbound.com has tweaked in some code in the leaflet code for making it region aware,
Sample marker definition:
var marker1 = new L.marker([-37.8, 145], {regions: ["Asia-Pac", "Australia", "VIC", "Melbourne"]} );
But the sample code says, every latitude longitude must be defined along with some extra parameter containing place information.
I could get the place information using reverse geocoding, but reverse geocoding every latitude longitude is time consuming right.
Highmaps provided by Highcharts is one another solution, but there, every country has code which should be assigned a value[count of point coordinates belonging to that country].
But all I have is latitude longitude points, no country or state information.
Thus, I need something which takes only a set of latitude longitude and does clustering based on country, state, district depending on the zoom level.
You have 2 separate needs in your questions:
Map your lat/lng coordinates to appropriate administrative areas. E.g. through the reverse geocoding that you mention.
Display "clusters" on those administrative areas depending on zoom level.
As for point 1, you know that lat/lng points do not say by themselves which administrative area(s) they belong to. So "reverse geocoding every latitude longitude" is a mandatory step. Whether time consuming or not depends on the solution you choose to perform this operation.
If I understand correctly, you would like a "framework" that could do that automatically for you. But frameworks are usually data agnostic, and if they do not have data about boundaries of those administrative areas, they cannot help you.
You may rather look for "services" (like the Mapbox Geocoding API that you mention) or software that would already have such data. It is not time consuming if you can program the lookup (or perform "bulk" operations) and if you are not limited by the requests rate and your amount of points to map (which may be the case with Mapbox).
You could very well set up your own application to perform this mapping:
As for the dataset for administrative areas boundaries, you would probably be interested in links in this post: Are there any free administrative boundaries available as shapefiles? If your points are limited to a few countries, it will be easier for you to find the appropriate data source(s).
Once you have that data, many GIS software should be capable of mapping your lat/lng points to the areas they belong to. This would be mainly for a "one-shot" operation, if your set of points do not change much.
A "web-compatible" alternative would be for example to use Leaflet with point in polygon for Leaflet plugin. You would need your boundaries data converted to GeoJSON format first. Again, GIS software should be capable of doing so, or many online services as well (search for "convert geojson" for example).
A server-side solution would avoid having to manage the entire boundaries data through network and in client browser (if you need to perform the mapping dynamically). I am sure many GIS servers are capable of performing this operation, once they are fed with the boundaries data.
For point 2, once you have completed the above step, I think you would have many options available, including those you mention (RegionBound, Highmaps).
Even with standard mapping libraries (Leaflet, OpenLayers 3), you would just need to build your "clusters" (markers on administrative areas with a number saying how many points are in there), like you have to do with Highmaps anyway for example.
Computing the number of "clustered" point is as easy as filtering your points per area name / code. Then switch the clusters to the desired administrative level when the map zoom changes.
So the key is really to determine first to which areas your points belong to (point 1).
Then a small question would rise about where to place the "cluster" marker:
On centroid of the administrative area? You need the coordinates of that centroid from your data source, or a good algorithm to compute it from the boundaries (good luck on that…).
On "center" of the bounding box of the area? Leaflet can easily compute that: from your area vector shape, you would do myShape.getBounds().getCenter().
On barycentre / centroid of the clustered points? This is what Leaflet.markercluster and RegionBound do (do not know for Highmaps).
Good luck!
I would like to use Mapbox's static API to serve some PNG images in which I have encoded georeferenced data, so that I can do some JavaScript data manipulation on the client side (I don't want to show these images). My problem is that this data cannot be changed - reprojected or scaled, and I only have it in EPSG:4326, not in EPSG:900913 and not in the resolution of any zoom level.
Is there a way to tell Mapbox to store the raster data in its original form, without changing it, and just serve a rectangular chunk of it centred on a particular location?
The short answer is you can't do this: Mapbox's API is ESPG:900913-only. The long answer is that if you really want to, you can use GDAL to represent your ESPG:4326 image as a non-geographic 900913 image. This is, to be clear, the long route and means that you'll need to do all of the reprojection math to determine the geographical transformation from the original data to the now-fake coordinates.
I have a program that uses the API to get altitude data of the screen by running through hundreds of thousands of latitude and longitude points. However, Google Earth's data refines itself as one zooms in. So I need to know the minimum altitude I can use to get the best data Google has to offer. I am at a loss to figure out how to do this.
Furthermore, I assume that this depends on the part of the world. I'm going to assume the best part of the world, always.
Thanks for any feedback.
There is no API for determining the quality of the underlying imagery. While this question is not an exact duplicate of Get ground altitude in a reliable way, the same general algorithm can be applied:
Zoom to the required lat/lon at altitude Z
Wait for the imagery to come in (as described in the linked question)
Zoom in "closer" (Z - [delta])
If Google has better imagery, the loaded percentage should drop, wait for it load
Repeat steps 3-4 until the progress is always ~100% (e.g., until no loading is required)
Even with this hack, I'm not sure it will yield reliable results. Your question is flawed for several reasons:
What does "the best data Google has to offer" mean?
You have a lat/lon coordinate. That's a single, infinitely small, point on the Earth
Raw satellite imagery typically covers large sections (many lat/lon points), so the "best" height would be to set the GE camera so that your view convers exactly one satellite image tile
Why do you need the "best" data?
Satellite imagery is expressed in terms of "area covered by a single pixel" (e.g., 1m = 1 pixel in the image covers 1sq m)
Knowing this, the camera height will vary image by image, even for tiles within the same satellite imagery data set (it shouldn't vary much -- but it could slightly.)
Are you trying to cache the imagery off the globe? If so, you should carefully review the TOS to make sure you're not in violation.
Note that if you are just looking to obtain satellite imagery -- there are many good (free) sources. USGS National Map Viewer should be able to get you pretty good imagery for the US (including territories).
I need to get the elevation in meters, of specific points within in a 1km square of ground.
Each point will be 5 meters apart, meaning a total of 40,000 specific points.
The elevation for each of these points will be stored in a 200x200 matrix.
I have tried to use the Google Maps Elevation API, but I think the amount of data I need to request will exceed the terms of service.
I also need to use the elevation data on Matlab, but reading the terms of service for the Google API, I believe I would be limited to using the data within Google Maps itself.
Please could you suggest a solution for me?
After reading all the Terms and Conditions for Google's elevation API, I believe you would be fine in using it for PERSONAL use in Metlab.
However, if you intend to publish the results or anything derived from the data, you will need to include a google map with it... but that could be in the form of a link to a map with just the 200x200 points plotted - a fifteen minute job to knock up ;)
Go for it :)