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Is there a way to get better resolution maps from USGS?

Thanks,

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Can you give a link to the exact layers you're you are referring to in both your questions? And preferably some example code that adds it to the map. If we can reproduce this, we're much more likely to be able to help you. –  CaptDragon Mar 8 '12 at 16:10
    
Here is a single request to the mapserver that returns an image with 2 county names: services.nationalmap.gov/ArcGIS/rest/services/TNM_Vector_Large/…{%22xmin%22%3A-13605383.531782%2C%22ymin%22%3A6058082.337924%2C%22x‌​max%22%3A-13604466.287443%2C%22ymax%22%3A6058999.5822633%2C%22spatialReference%22‌​%3A{%22wkid%22%3A102113}}&size=2048%2C2048 –  user1137894 Mar 8 '12 at 20:01
    
Are the county names baked into the images or is there a way to modify the request to have the county name removed from the image? –  user1137894 Mar 8 '12 at 20:01
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Not sure. I would imagine since it's vector data you should be able to have the county name modified/removed. And just an FYI, whenever someone asks for information or clearification, you can make an edit to your original question and just paste it in at the bottom. Unless it's something very small. –  CaptDragon Mar 8 '12 at 20:06
    
That link you posted in the comment, can you post that in your original question as a link. It's broke and i can't get to it. Thanks. But this is vector data, you should be able to get any resolution you want just put it in the query string &dpi=300 –  CaptDragon Mar 8 '12 at 21:13
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1 Answer

up vote 2 down vote accepted

ArcGIS Server treats each request as a unique, complete map. So, it will add labels to all features that you requested. What you're doing is equivalent to setting up 100 computers on a gymnasium wall, then standing back and looking at them all at once.

Since this is a dynamic map, you can improve the looks somewhat by increasing the value of the DPI argument that you send to the export operation. However, the server may switch the renderer or the layer visibility based on what it calculates the visible scale to be at the DPI you request.

To remove the repeated labels, you must omit the layers that are being labeled from the request. In your example this is the County Boundary layer, which is within the Boundaries group layer. By specifying an "exclude" parameter with the IDs of the two Boundaries groups, you can draw an image without the labels as follows:

http://services.nationalmap.gov/ArcGIS/rest/services/TNM_Vector_Large/MapServer/export?bbox=%7B%22xmin%22%3A-13605383.531782%2C%22ymin%22%3A6058082.337924%2C%22xmax%22%3A-13604466.287443%2C%22ymax%22%3A6058999.5822633%2C%22spatialReference%22%3A%7B%22wk+%E2%80%8Bid%22%3A102113%7D%7D&bboxSR=102100&layers=exclude%3A1%2C32%2C9%2C40&layerdefs=&size=2048%2C2048&imageSR=102100&format=png24&transparent=true&dpi=150&time=&layerTimeOptions=&f=image

You could further improve the rendering quality by requesting the features as vectors (rather than images) and drawing them on the client side. You would have to do a lot more work on the client side to get this done, though!

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