preview_images.txt

In order to work with preview images using web service the access to preview images 
folder should be granted on the server. For this add the following element to the Host element
from the conf/server.xml in your tomcat installation folder:

<Context path="/url_pattern" docBase="c:/path/to/preview/images/folder" />

where the /url_pattern should be part of dataSetService.previewImagesURLPrefix property
from application.properties file for web service.

For example, on test machine we have:
<Host name="localhost"  appBase="webapps"
            unpackWARs="true" autoDeploy="true"
            xmlValidation="false" xmlNamespaceAware="false">

   <Context path="/nasa_pds_static_image" docBase="a:/preview_images" />

</Host>

and in application.properties:
dataSetService.previewImagesURLPrefix=http://localhost:8080/nasa_pds_static_image