Week11- Georeferencing "Making Here Go There"

When you want to know where "Yonder" is, georeferencing is a good skill to know.  Using known points on the ground, matching them up with a known point on a picture connects the picture to the geographical coordinate systems on the ground.  That's also how they can find you through pictures taken by your cell phone.   Now I understand how they can get the two to line up.  We also added a building to the vector files and drew in a road.  Cool stuff.

 

Process Summary  

1-Created new folder for  s:\Introgis\ Week11GeoREF. Moved new georeferencing.zip, extracted files.

2-Began in ArcCatalog to obtain metadata information, see that GCS is NAD 1983 Harn Stateplane Florida North 0903 feet.  See that uwf_DEM and uwf_n & uwf_n1.jpeg will need coordinate systems added.

3- New map added  buildings & roads.shp, then  uwf_n.jpeg to map. Added georeferencing toolbar to  data frame. Received message there was no coordinate system.  Saved map as  Week11UwmGEO.mxd.

4- Verified uwf_n.jpeg is active layer in georeferencing toolbar.>fit to display, It appears.  

5-Task 5, began to add control points.  Before added first one, studied 3 layers.  First 5 RMS for first time with this was just over 7, added 5 more control points, RMs under 15. Chose to scrap all and do second set, much better.  Found that using full extent & zooming took time for the computer to process each strip of raster cells. Good idea not to rush computer or completion of adding control points. Best scale for adding control points is between 1:250-400. 

6- With the do over, I started with three points set out much like a three legged stool, which established a clean “plane”.  Added the extra control points,  the georeferencing  proceeded much smoother with much less distortion during the control point establishing process.

7-Task 6- Total RMS with 10 control points 4.32, using 1^st polynominal.  (RMS at 5 points 1.26357), updated georeferencing.  Checked layer, properties, source, has same GCS as buildings.shp.

8-Task7- Added uwf_s1.jpeg to map.  Can see right off that the image is quite distorted.  

First took time to study image. Chose three points in most outer regions of image to establish as original plane under 1 st polynominal.  After reached 6 total control points, viewed lin                                                                                                                                          ks table, moved to 2^nd polynominal , check RMS running high at 9.19275, tried to adjust image, moved it up in layers over uwf_n.jpeg did something & lost all my control points. Had not saved my work. 

9- With uwf_s1.jpeg back to originally distorted image again, started reestablishing control points. Started with same goal of three outer points in various locations on image to create “three-legged plane”,  having a little more practice at this task, it went smoothly.  Ending with 2^nd polynominal and 9 control points  my final RMS was 1.78562.  Saved work several times between points.  The image is square, used hand  ruler against screen to visually check it.  Updated georeferencing,  checked in properties>source> GCS was NAD 1983 Harn Stateplane Florida North 0903 foot.

10- Moved uwf_n.jpeg above uwf_1s.jpeg. Verified with enlarge tool that there was no gap or gore between the images.  In properties>symbology>display background value> left 000 as default values, then black areas around image were removed.

11- Task 8- Followed instructions, using editing tool from last week, enlarged area of gym,  digitized new building (gym) added to image, saved.  Same with road added, editing tool end>started editing>roads layer>attribute table>added data, checked snapping tool for end, vertex. Added road, it went in smooth.  Finally.

12- Task 9- Creating 3D scenes. Opened ArcScene, added layers, roads, buildings, uwf_n.jpeg & uwf_s1. In properties>base heights> set floating on custom as uwf_dem for each layer. In uwf_n.jeg & uwf_s1 properties >symbology> set display background value at default 000 for each layer. This cleaned up the map and removed a blackish strip between the uwf layers.   Before I began making  any changes, I saved a copy of the base file as Week11uwfcamp_copy.sxd.

13-Futher adjustments to map in Buildings>properties>Extrusion>checked extrude features in layer> in extrusion value or expression  typed [Height], in drop down activated  made sure “adding it to each feature’s maximum height is chosen.

14-To exaggerate the vertical dimensions, on main menu>view>scene properties>general tab>vertical exaggeration >5>ok.

15-Adjusted view to show the new building 072 & new road added. Exported from Arcscene10 in 2D to s drive as jpeg.  Saved as  week11uwfcamp.jpg   Added to arcmap in new map.  Eventually able to make map with elements, small map of whole area.  Once again had trouble saving, called IT, this is an issue which needs to be resolved.  Will send screen shot to IT when comes again.