Tag Info

Hot answers tagged

7

Why use a database? Because it's not necessarily the case, especially with larger datasets, that you can expect to be able to push the entire thing to the client. If you're talking thousands of points, then sure, but for millions of points you probably don't want each and every one represented in RAM on your end users' client. Not everyone has a super fast ...


6

It actually seems very reasonable from a price perspective. I would specify it meets XXXX standard of accuracy and I would specify the file be in las 1.2 (or another spec as desired). Specify the classes you require and the RMSEz that is acceptable (often just vertical in lidar). 7 points per m is high. I find this document very useful. It spells out what ...


5

You can get Sentinel-1 data from scihub.esa. Requires only registration (And most likely, non-commercial use). As Sentinel-1 has just become operational the archive is not very extensive but should grow quite quickly. You can set request data-access propospal on Alaska Satellite Facility. Some data open access. For ALOS-PALSAR you must be a resident of the ...


5

Only managed to find a couple of sources for SAR images and data: You can download SAR images from here which are mostly focused on ecological sites such as forests: You can download SAR samples from here which contain fairly large datasets (note: the last 4 links at the bottom of the SAR section are dead) Hope this helps.


4

This information is captured in the alternate names field in the GeoNames database. You'll need the alternatenames.zip file that contains lists of names like: 2020600 2634688 fr Gare de Londres Waterloo 2020602 2634688 de London Waterloo Station 2020603 2634688 pl Waterloo Station 2020604 2634688 fi Waterloon rautatieasema 2020605 ...


4

You can download hydrology shapefiles from here for a number of countries around the world. Select your country of choice and Inland water as your subject. You should receive 2 types of shapefiles: A line shapefile depicting line features for rivers, canals and basins A polygon shapefile depicting area features for rivers, canals and basins I believe ...


3

I have made hydrologically correct river-channels for the Lake Victoria basin. SRTM 90m does a reasonable but imperfect job. For example, I had to adjust numerous regions based on the actual flow of rivers. All is not lost though it sounds as though we can expect the 30m global dataset soon. I would suggest a dry run with 90 m data and then a rerun when the ...


3

If you are only interested in the attribute table, you can use the Summary Statistics tool, where 'Statistics Fields' = fields to sum, 'Statistics Type' = SUM, and 'Case Field' = ID.


3

Ordnance Survey As the name suggests, OS Terrain 50 is a product with a 50 metre grid resolution (http://www.ordnancesurvey.co.uk/business-and-government/products/terrain-50.html). OS Terrain 50 has been compared with GPS points in a range of sample areas to provide a Route Mean Square Error (RMSE) value for the height points in each geographic ...


3

Thankfully, the Internet Archive has archived this data, and offers it for download. All the different versions are tagged with the geoplanet keyword. The latest version available is 7.10.0 and can be downloaded from this page.


3

This link from geofabrik.de provide shape files for roads and other features from open layers categorized into countries and for India covering almost all urban area. For urban boundary or district boundary shape files for India this link would be helpful.


3

The background image of the Openlayers plugin is a set of tiles in raster format. You can not convert that to anything useful. You can digitize the features you want on the basis of the background download Openstreetmap data (one of the available backgrounds of Openlayers) and filter that for the data you need.


2

I'm not sure exactly what kind of TIF format a LISS3 image is, but I will assume that it is a geoTIFF as this is the case for most satellite data. Whitebox GAT can import uncompressed, single band GeoTIFF images simply by selecting them from the list of available files when you press 'Add Layer'. You can open multiple images at a time as well: Whitebox ...


2

You can also download from DIVA-GIS: http://www.diva-gis.org/gdata Select India and then select the subject of the attributes such as: Administrative areas (boundaries) Roads Railroads Land cover Population


2

Start by considering synonyms for what you're calling "colloquial area", other than district or ward: neighborhood, region, zone, etc. See if there are already maps of such areas. Real estate agents often divide cities up into well-known but unofficial areas because they wish to group properties roughly according to market value and accepted colloquial ...


2

DIVA GIS will give you roads and municipalities (and I think departments). OSM will give you roads, municipalities and some POIs (and I think departments). Natural Earth will give you municipalities and roads (and I think departments). GeoCommunity will give you roads, municipalities and places (and I think departments). GeoNames will give you places.


2

For viewing bus routes you can take a look at OSM-based maps which visualize bus routes. The OSM wiki has a list of public transport maps, for example the transport layer at the front page or the Öpnvkarte. For retrieving bus route data you can use the Overpass API or the nice frontend overpass turbo. Use this query for retrieving all bus routes in the ...


2

You can use the Dissolve tool. You choose the dissolve field (ID) and then SUM for the statistics.


2

JAXA have made global L-band SAR mosaics at 50 m spatial resolution available from the PALSAR sensor: http://www.eorc.jaxa.jp/ALOS/en/palsar_fnf/fnf_index.htm Registration is required to download the data.


1

Right click the field and choose "Summarize" then choose your field and the method by which to summarize that field. Sum is what you are looking for.


1

You can try finding a station on Wunderground that fits your needs and then use their API to get what you want.


1

These pages on the OSM Wiki will help you determine the necessary tags for the data you need: Bus Stop, Stations, etc Bus Routes You can see what actual data is available in your area of interest by using the OSM Overpass Turbo Tool. Use the Wizard to create a subset of the available data using the tags described above


1

OpenData BoundaryLine (Ordnance Survey) ONS Postcode Directory (ONSPD) May 2014 edition. This includes full UK (including Northern Ireland) Code-POINT Code-Point Open (May 2014) This is a mirror that is updated yearly (or better) http://parlvid.mysociety.org/os/ Using all three you can build up a postcode to at best a district and a ward (We have done ...


1

Neighbourhood names are tricky, one possible source is the Flickr Shapefiles. You could look at Tom Taylor's work (referred to from here) but it seems not to be working today.


1

This is an interesting piece on such data for the UK. Public data in the UK is often not-public, including post codes Anyway the article provided via the link above will give you a direct link to the data you require. I'll let you decide on the morality of using wikileaks for such information.


1

Did you edit the data in that table at all? It's strange how there is one row with its lat/longs in DDMMSS when all the others (the ones that aren't blank) are in decimal degrees. Also, do the points which are missing positional data actually show up in ArcMap? Are they where they're supposed to be? As far as the missing data, it looks like everything went ...


1

I finally managed to do this. I created a new field (called it joinfield) with the $rownum expression I created a set of consecutive numbers (1,2,3...). I duplicated the attribute table, created another joinfield, amd this time I used $rownum - x (the time lag you want to apply, in my case, 8 minutes). If the delay is the other way around you can use ...


1

Frequently updated OpenStreetMap data licensed under OdbL might be an option for you. They can be downloaded from http://openstreetmapdata.com/data/coastlines in WGS84


1

take a look at what I've got here - https://github.com/geohacker/india. Contains District, State and Taluk level shapefiles for India, based on the GADM data.


1

You could try here. They seem to have a lot of shape files that might fit your description. Though the European dataset is in 30 year increments. Your best bet is probably going to have to be recreate it. Wikipedia has some WWI maps in PNG format. As others have mentioned, there are plenty of sites with historical raster maps that you could digitize.



Only top voted, non community-wiki answers of a minimum length are eligible