diff --git a/isis/src/base/apps/topds4/20190612T090019S776_map_L0pan.xml.full b/isis/src/base/apps/topds4/20190612T090019S776_map_L0pan.xml.full
index c9eea369c0..9c742be987 100644
--- a/isis/src/base/apps/topds4/20190612T090019S776_map_L0pan.xml.full
+++ b/isis/src/base/apps/topds4/20190612T090019S776_map_L0pan.xml.full
@@ -389,63 +389,63 @@
     </Observation_Area>
     <File_Area_Observational>
         <File>
-            <file_name>20190612T090019S776_map_L0pan.fits</file_name>
-            <creation_date_time>2020-01-17T19:16:18.256Z</creation_date_time>
-            <file_size unit="byte">4443840</file_size>
+            <file_name>{{imageFileName()}}</file_name>
+            <creation_date_time>{{currentTime()}}</creation_date_time>
+            <file_size unit="byte">{{outputFileSize()}}</file_size>
         </File>
         <Header>
             <offset unit="byte">0</offset>
-            <object_length unit="byte">17280</object_length>
-            <parsing_standard_id>FITS 3.0</parsing_standard_id>
+            <object_length unit="byte">{{ int(MainLabel.IsisCube.Core.StartByte.Value) - 2}}</object_length>
+            <parsing_standard_id>ISIS3</parsing_standard_id>
         </Header>
         <Array_2D_Image>
             <local_identifier>Active Area</local_identifier>
-            <offset unit="byte">17280</offset>
+            <offset unit="byte">{{ int(MainLabel.IsisCube.Core.Pixels.Multiplier.Value) - 1}}</offset>
             <axes>2</axes>
             <axis_index_order>Last Index Fastest</axis_index_order>
             <description>OCAMS image 1024 by 1024 pixel active array.</description>
             <Element_Array>
                 <data_type>UnsignedMSB2</data_type>
                 <unit>DN</unit>
-                <scaling_factor>1</scaling_factor>
-                <value_offset>32768</value_offset>
+                <scaling_factor>{{MainLabel.IsisCube.Core.Pixels.Multiplier.Value}}</scaling_factor>
+                <value_offset>{{MainLabel.IsisCube.Core.Pixels.Base.Value}}</value_offset>
             </Element_Array>
             <Axis_Array>
                 <axis_name>Line</axis_name>
-                <elements>1024</elements>
+                <elements>{{MainLabel.IsisCube.Core.Dimensions.Lines.Value}}</elements>
                 <sequence_number>1</sequence_number>
             </Axis_Array>
             <Axis_Array>
                 <axis_name>Sample</axis_name>
-                <elements>1024</elements>
+                <elements>{{MainLabel.IsisCube.Core.Dimensions.Samples.Value}}</elements>
                 <sequence_number>2</sequence_number>
             </Axis_Array>
         </Array_2D_Image>
         <Header>
-            <offset unit="byte">2116800</offset>
-            <object_length unit="byte">2880</object_length>
-            <parsing_standard_id>FITS 3.0</parsing_standard_id>
+            <offset unit="byte">0</offset>
+            <object_length unit="byte">TBD</object_length>
+            <parsing_standard_id>ISIS3</parsing_standard_id>
         </Header>
         <Array_2D_Image>
             <local_identifier>Active Array and Extended Pixel Regions</local_identifier>
-            <offset unit="byte">2119680</offset>
+            <offset unit="byte">TBD</offset>
             <axes>2</axes>
             <axis_index_order>Last Index Fastest</axis_index_order>
             <description>OCAMS 1044 sample by 1112 line extended pixel array. The extended pixel array contains the detector overscan and dark pixels.</description>
             <Element_Array>
                 <data_type>UnsignedMSB2</data_type>
                 <unit>DN</unit>
-                <scaling_factor>1</scaling_factor>
-                <value_offset>32768</value_offset>
+                <scaling_factor>TBD</scaling_factor>
+                <value_offset>TBD</value_offset>
             </Element_Array>
             <Axis_Array>
                 <axis_name>Line</axis_name>
-                <elements>{{MainLabel.IsisCube.Core.Dimensions.Lines.Value}} </elements>
+                <elements>TBD</elements>
                 <sequence_number>1</sequence_number>
             </Axis_Array>
             <Axis_Array>
                 <axis_name>Sample</axis_name>
-                <elements>1112{{MainLabel.IsisCube.Core.Dimensions.Samples.Value}}</elements>
+                <elements>TBD</elements>
                 <sequence_number>2</sequence_number>
             </Axis_Array>
         </Array_2D_Image>
diff --git a/isis/src/base/apps/topds4/topds4.cpp b/isis/src/base/apps/topds4/topds4.cpp
index 84b8abf217..51b39d4d45 100644
--- a/isis/src/base/apps/topds4/topds4.cpp
+++ b/isis/src/base/apps/topds4/topds4.cpp
@@ -5,6 +5,7 @@
 #include <inja/inja.hpp>
 
 #include "md5wrapper.h"
+#include "QFile.h"
 
 #include "topds4.h"
 
@@ -30,6 +31,9 @@ namespace Isis {
     Process p;
     p.SetInputCube(icube);
 
+    // NEED TO WRITE AND CLOSE THE OUTPUT FILE BEFORE RENDERING SO THE FILE SIZE CALLBACK CAN GET THE FINAL FILE SIZE
+    QString outputFile = ui.GetFileName("TO");
+
     json dataSource;
 
     Pvl &cubeLabel = *icube->label();
@@ -50,13 +54,8 @@ namespace Isis {
       // get the xml label and add it to the template data
     }
 
-    std::cout << "=============Data================" << std::endl;
-    std::cout << dataSource.dump(4) << std::endl;
-    std::cout << "=================================" << std::endl;
-
-
     Environment env;
-    // Call back functions
+    // Template engine call back functions
     /**
      * Renders to the current UTC time formatted as YYYY-MM-DDTHH:MM:SS
      */
@@ -76,6 +75,14 @@ namespace Isis {
       return (cubeFilename.split(".")[0] + ".img").toStdString();
     });
 
+    /**
+     * Renders to the final file size in bytes of the output cube or img
+     */
+    env.add_callback("outputFileSize", 0, [outputFile](Arguments& args) {
+      FileName cubeFilename = outputFile;
+        return QFile(outputFile).size();
+    });
+
     /**
      * Renders to the MD5 hash for the input cube
      */
@@ -85,13 +92,18 @@ namespace Isis {
     });
 
     std::string inputTemplate = ui.GetFileName("TEMPLATE").toStdString();
-
     std::string result = env.render_file(inputTemplate, dataSource);
 
     std::ofstream outFile(ui.GetFileName("TO").toStdString());
     outFile << result;
     outFile.close();
 
+    if (ui.WasEntered("DATA")) {
+      std::ofstream jsonDataFile(FileName(ui.GetFileName("DATA")).expanded().toStdString());
+      jsonDataFile << dataSource.dump(4);
+      jsonDataFile.close();
+    }
+
     std::cout << "============Result===============" << std::endl;
     std::cout << result << std::endl;
     std::cout << "=================================" << std::endl;
diff --git a/isis/src/base/apps/topds4/topds4.xml b/isis/src/base/apps/topds4/topds4.xml
index c29862bc69..9f9ef6d0dd 100644
--- a/isis/src/base/apps/topds4/topds4.xml
+++ b/isis/src/base/apps/topds4/topds4.xml
@@ -2,20 +2,28 @@
 
 <application name="topds4" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="http://isis.astrogeology.usgs.gov/Schemas/Application/application.xsd">
   <brief>
-    dummy
+    Convert from ISIS3 cube to PDS 4 format using template XML files
   </brief>
 
   <description>
-    dummy
+    <p>
+      Writes a PDS4 compatible label file and image file. The contents of the label file are 
+      generated useing the template file specified by the TEMPLATE parameter.
+    </p>
+    <p>
+      The image file is generated from the input ISIS cube specified by the FROM parameter.
+      The format of the output image file can be either an ISIS cube or a raw binary file containing
+      only the image DNs (i.e., no header or trailing data).
+    </p>
   </description>
 
   <category>
-    <categoryItem>Trim and Mask</categoryItem>
+    <categoryItem>Import and Export</categoryItem>
   </category>
 
   <history>
-    <change name="Jeffrey Covington" date="2015-01-15">
-      Removed unreachable code.
+    <change name="Stuart Sides" date="2021-01-03">
+      Original version
     </change>
   </history>
 
@@ -28,7 +36,7 @@
           Input cube
         </brief>
         <description>
-          This is the input cube that will be cropped.
+          This is the input cube that will be converted to PDS4 format.
         </description>
         <filter>
           *.cub
@@ -42,7 +50,10 @@
           Input template
         </brief>
         <description>
-          Input template
+          The file name of the input template. This file contains "inja" compatible 
+          template syntax inside of a PDS4 XML label. The data used to replace the 
+          template elements comes from the ISIS cube label, the original label 
+          (PDS3, FITS, PDS4), and other input PVL, XML, or JSON files.
         </description>
       </parameter>
 
@@ -53,9 +64,26 @@
           Output PDS4 label
         </brief>
         <description>
-          The.
+          The output file name of the PDS4 label. The output image name will be derived from this
+          parameter by removing the last extension and adding .cub
+        </description>
+      </parameter>
+
+      <parameter name="DATA">
+        <type>filename</type>
+        <internalDefault>None</internalDefault>
+        <fileMode>output</fileMode>
+        <brief>
+          Output JSON data
+        </brief>
+        <description>
+          The output file name to store the template data source. This is a dump of the JSON data used
+          by the template engine to fill in the template elements. It is a combination of the ISIS
+          main cube lable, the original lable, and any other data sources supplied. The purpose of this
+          parameter is for debugging the templates.
         </description>
       </parameter>
+
     </group>
   </groups>
 </application>