Difference between revisions of "Field-setup Guideline"

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     '''1.2.  Field Setup'''  
 
     '''1.2.  Field Setup'''  
 
                
 
                
             ❏ Early in the crop season, distribute at least 10-15 ground control points (GCP) uniformly throughout the field. Four GCPs fixed in the field corners and rest  
+
             ❏ Early in the crop season, distribute at least 10-15 ground control points (GCP) uniformly throughout the field. Four GCPs should be fixed at the field corners and the rest  
 
               distributed inside the field, preferably, in the alley ways for better visibility.  Survey the GCPs with either RTK or a DGPS GNSS systems (whichever available) multiple times during the season to reduce the day/time bias.  
 
               distributed inside the field, preferably, in the alley ways for better visibility.  Survey the GCPs with either RTK or a DGPS GNSS systems (whichever available) multiple times during the season to reduce the day/time bias.  
               Make sure the GCPs are not disturbed/moved from their fixed positions once surveyed throughout the crop season.   
+
               Make sure the surveyed GCPs are not disturbed/moved from their fixed positions throughout the crop season.   
               Generally, the white color GCPs are easy to spot, hence, should be preferred.  Some photogrammetry softwares support automatic GCP detection. When  
+
               Generally, the white color GCPs are easy to spot, hence, should be preferred.  Some photogrammetry software support automatic GCP detection. When  
 
               available, these software customized GCPs can also be used.  Here are a few examples of GCPs that have worked well for us:
 
               available, these software customized GCPs can also be used.  Here are a few examples of GCPs that have worked well for us:
 
                        
 
                        
 
                   i. Metal sheets screwed on top of the iron rods (example)[[File:Example.jpg]].
 
                   i. Metal sheets screwed on top of the iron rods (example)[[File:Example.jpg]].
 
                   ii. Color brick/pavers (example)[[File:Example.jpg]]
 
                   ii. Color brick/pavers (example)[[File:Example.jpg]]
                  iii. Plastic discs/frisbees
+
               
 
              
 
              
 
             ❏ Place the reference calibration panel on a flat surface close to the first mission waypoint at a  
 
             ❏ Place the reference calibration panel on a flat surface close to the first mission waypoint at a  
                 fixed position (Figure 1.1)  
+
                 fixed position (Figure 1.1). It is important to put the reference panels in the exact same orientation and position for each flight. This is to facilitate automatic processing of the panels based on coordinate positions. Small-size stakes/flags can be used to mark the corners of panels. 
 
              
 
              
              Note: The panel can also be utilized as a launchpad expecially when it is wide. Also, in order to minimize the variations due to varying sun illumination and overcast, maximum
 
              aerial shots of calibration panel at regular intervals are recommended. This can be achieved either
 
              by using multiple calibration targets or by capturing images of a target at every landing and takeoff event during the mission. A 20% gradient grayscale calibration panel can be used as a reference panel. The details to build a calibration panel are described in this document.
 
 
              
 
              
             ❏ Mark the four corners of calibration panel with flags and survey them with RTK or DGPS GNSS system.
+
             ❏ The panel can also be utilized as a launchpad especially when it is wide.  
                
+
               Also, in order to minimize the variations due to varying sun illumination and overcast, maximum
               Fixed panel positions make the automatic extraction of individual color panels easier during the post-processing.
+
               aerial shots of calibration panel at regular intervals are recommended. This can be achieved either
             
+
              by using multiple calibration targets or by capturing images of a target at every landing and takeoff event during the mission. A 20% gradient grayscale calibration panel can be used as a reference panel. The details to build a calibration panel are described in the following sections.
 +
 
 
               '''Figure 1.1''': Example of a grayscale calibration panel attached on a metal frame.
 
               '''Figure 1.1''': Example of a grayscale calibration panel attached on a metal frame.

Revision as of 14:49, 26 April 2016

Flight Checklists

   1.2.  Field Setup 
             
           ❏ Early in the crop season, distribute at least 10-15 ground control points (GCP) uniformly throughout the field. Four GCPs should be fixed at the field corners and the rest 
             distributed inside the field, preferably, in the alley ways for better visibility.  Survey the GCPs with either RTK or a DGPS GNSS systems (whichever available) multiple times during the season to reduce the day/time bias. 
             Make sure the surveyed GCPs are not disturbed/moved from their fixed positions throughout the crop season.  
             Generally, the white color GCPs are easy to spot, hence, should be preferred.  Some photogrammetry software support automatic GCP detection. When 
             available, these software customized GCPs can also be used.  Here are a few examples of GCPs that have worked well for us:
                     
                 i. Metal sheets screwed on top of the iron rods (example)File:Example.jpg.
                 ii. Color brick/pavers (example)File:Example.jpg
               
            
           ❏ Place the reference calibration panel on a flat surface close to the first mission waypoint at a 
               fixed position (Figure 1.1). It is important to put the reference panels in the exact same orientation and position for each flight. This is to facilitate automatic processing of the panels based on coordinate positions. Small-size stakes/flags can be used to mark the corners of panels.  
            
           
           ❏ The panel can also be utilized as a launchpad especially when it is wide. 
              Also, in order to minimize the variations due to varying sun illumination and overcast, maximum 
              aerial shots of calibration panel at regular intervals are recommended. This can be achieved either 
              by using multiple calibration targets or by capturing images of a target at every landing and takeoff event during the mission. A 20% gradient grayscale calibration panel can be used as a reference panel. The details to build a calibration panel are described in the following sections.
              Figure 1.1: Example of a grayscale calibration panel attached on a metal frame.