I know that this is an old question and already has an accepted answer. However, the answer goes over exporting the layer as an image. It doesn't seem to answer the OP's question. Because this is the first question that showed up when I was looking up this problem, I felt that I would add my solution here for others to try.
I first created a new ArcGISDynamicMapServiceLayer
with the MapServer's URL, then used the .setVisibleLayers
function to denote which layers in the MapServer should be displayed.
I can't use the OP's example MapServer because it has been taken down. But lets use esri's state, city, highway layer as an example. If I only want to show the highways on the map:
var newLayer = new ArcGISDynamicMapServiceLayer('http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer');
var layerIds = [0];
newLayer.setVisibleLayers(layerIds);
map.addLayer(newLayer);
If I wanted to show highways and states, then I would just replace the [0] with [0, 2].
This is how QGIS writes the proj-string and WKT with +towgs84-parameter:
+proj=longlat +ellps=bessel +towgs84=598.1,73.7,418.2,0.202,0.045,-2.455,6.7 +no_defs
GEOGCS["DHDN",DATUM["Deutsches_Hauptdreiecksnetz",SPHEROID["Bessel 1841",6377397.155,299.1528128,AUTHORITY["EPSG","7004"]],TOWGS84[598.1,73.7,418.2,0.202,0.045,-2.455,6.7],AUTHORITY["EPSG","6314"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4314"]]
But keep in mind that there is no overall value for converting any Bessel-1841-Data to WGS84.
For Germany, there were a lot of parametres published, until a NADgrid for the whole country was created. This applies the correct shift for every point inside Germany.
Other surveying authorities have done similar conversions, but with other values.
EDIT
There is a forum entry in Russian http://gis-lab.info/forum/viewtopic.php?t=9386
giving the following proj parameters:
+proj=tmerc +lat_0=55.6666666667 +lon_0=37.5 +x_0=0 +y_0=0 +k_0=1. +a=6377397 +rf=299.15 +towgs84=396,165,557.7,-0.05,0.04,0.01,0 +no_defs
Maybe you get lucky with those values.
Best Answer
There is an option to specify the SpatialReference when creating the map using the extent option. The dynamic map service layer should automatically project onto the map's spatial reference. It would look something like this
A working sample of this is provided on the documentation page. For more information on how to create an Extent, take a look at the API documentation for extent.