PROJECTION UTILITY MJ
Have you ever had the need for a tool that is able to obtain
- an estimated optimal maximum BoundingBox for a given SRID, or
- a list of appropriate SRIDs for a given Lon/Lat coordinate pair?
Well, we had — That's why we built this tool to help in the described circumstances.
Feel free to use this service, but be aware that we cannot give any guarantees whatsoever.
Example Application
![](./img/map.png)
Usage
Show this manual
Parameters
mode
-
(mandatory, fixed, case-insensitive)
manpage
errorformat
-
(optional) the return format in case of an error. Can be
either
html
(the default) orjson
.
Iferrorformat
isjson
, we return a JSON-object with a membererror
, that has a membermsg
which contains the readable error message.
Example
http://webmapcenter.de/projection-utility/index.php?mode=manpage
Obtain a BoundingBox for a given SRID
Parameters
mode
- (mandatory, fixed, case-insensitive)
getbbox
srs_num
- (mandatory) The number after "EPSG:" in an EPSG-key. Maximum length is 6 digits. Example:
31467
format
- (optional) Outputformat of the response. Can be either
json
(the default) orjsonp
. If the format isjsonp
, you should include a parametervarname
, see below. varname
- (optional) Only relevant if parameter
format
isjsonp
. The name of the variable we assign the output to. Can only contain the characters from a-z and those from A-Z. Note: We know that this covers only a subset of valid JavaScript identifiers. funcname
- (optional) Only relevant if parameter
format
isjsonp
. The name of the JavaScript method or function to call. Must start with a character from a-z or from A-Z or the underscore (_), can include characters a-z, A-Z, the underscore (_) and numbers from 0-9 for the following chars. You are allowed to call methods of objects likemy_object.my_method
errorformat
- (optional) the return format in case of an error. Can be
either
html
(the default) orjson
.
Iferrorformat
isjson
, we return a JSON-object with a membererror
, that has a membermsg
which contains the readable error message.
Output of a valid call
We return a GeoJSON (http://geojson.org) FeatureCollection either as plain object or stored in a JavaScript-variable (see parameters above).
The FeatureCollection always contains two features: The first represents an appropriate boundingbox in WGS84 (lon/lat, EPSG:4326). The second feature represents the same bounding box in the given SRID, i.e. the coordinates are projected.
Example
http://webmapcenter.de/projection-utility/index.php?mode=getbbox&srs_num=31467
Obtain an appropriate SRID for a given Lon/Lat coordinate pair
Parameters
mode
- (mandatory, fixed, case-insensitive)
getsrids
lon
- (mandatory) The longitude of the point you search appropriate SRIDs for, e.g.
8
lat
- (mandatory) The latitude of the point you search appropriate SRIDs for, e.g.
50
max_world_coverage
- (optional, default
100.0
) Filters the result by only including SRIDs whose BoundingBox is smaller than given percentage of the worlds area, e.g.50.0
format
- (optional) Outputformat of the response. Can be either
json
(the default) orjsonp
. If the format isjsonp
, you should include a parametervarname
, see below. varname
- (optional) Only relevant if the parameter
format
isjsonp
. The name of the variable we assign the output to. Can only contain the characters from a-z and those from A-Z. Note: We know that this covers only a subset of valid JavaScript identifiers. funcname
- (optional) Only relevant if parameter
format
isjsonp
. The name of the JavaScript method or function to call. Must start with a character from a-z or from A-Z or the underscore (_), can include characters a-z, A-Z, the underscore (_) and numbers from 0-9 for the following chars. You are allowed to call methods of objects likemy_object.my_method
errorformat
- (optional) the return format in case of an error. Can be
either
html
(the default) orjson
.
Iferrorformat
isjson
, we return a JSON-object with a membererror
, that has a membermsg
which contains the readable error message.
Output of a valid call
We return a JSON (http://json.org) object either as plain object or stored in a JavaScript-variable (see parameters above).
The returned object has a member srids
which holds an array of EPSG-codes.
Example
http://webmapcenter.de/projection-utility/index.php?mode=getsrids&lon=7&lat=50
Credits
The site http://spatialreference.org is used extensively to dynamically build up this tool's database. Thanks go to the creators of spatialreference.org for building such a wonderfull resource.
This site is provided by terrestris GmbH & Co. KG, Bonn, Germany. Idea and implementation by Christian Mayer and Marc Jansen.
If you are interested in the source of this tool, you are heavily encouraged to contact us.