Changes between Version 26 and Version 27 of Sensors/LeicaLIDAR/MikesNotes

Timestamp:

Sep 5, 2008, 4:06:29 PM (16 years ago)

Author:

mggr

Comment:

--

Sensors/LeicaLIDAR/MikesNotes

@@ -11 +11 @@
  * problem uploads to go to incoming/ dir
 
-
-
-== Mission planning considerations ==
-
-Water absorbs IR, so expect poor returns from wet surfaces.  Ideally one should wait for a whole dry day after rain.
-
-For differential GPS, aim to have a base station nearby (within 20km) and ideally in center of the scene.  Base station data should be recorded at 2Hz
-
-Ideally choose a time with a good GPS constellation (lots of satellites, PDOP >= 4).
-
-Consider terrain and minimum target size to determine required point density.  Steep terrain may cause shadowing effects due to perspective.
-
-Consider reflectivity of surface - lighter surfaces need less laser power.  Too high a power means intensity overflows on the reflection, which mess up the range - AGC should deal with this for large areas but it should be considered in planning, particularly for small bright targets on a generally darker background.  Assume 10% reflectivity is typical.
-
-Recommended to do a figure 8 loop at the start and end of the data acquisitions to make the IMU happy.  Need one at the end for reverse navigation processing.
+--------------------------
 
 == Overall system design and comments of note ==
@@ -86 +72 @@
 This apparently takes another week long training course.  We do have the basic software to do it but limited knowledge.  Basic process is to determine the camera parameters, correct and overlay the images, keeping ideally only the most central parts.  You then have to manually check through, especially along seams, and manually move the seam line in some instances (e.g. when perspective effects result in odd errors due to the seam hitting a tall building).
 
+--------------------------
 
 == Recommendations ==
 
 Perform calibrations frequently at the start of the period to get a feel for how they hold.  Reduce down to fit circumstances over time.
+
+=== Mission planning considerations ===
+
+Water absorbs IR, so expect poor returns from wet surfaces.  Ideally one should wait for a whole dry day after rain.
+
+For differential GPS, aim to have a base station nearby (within 20km) and ideally in center of the scene.  Base station data should be recorded at 2Hz
+
+Ideally choose a time with a good GPS constellation (lots of satellites, PDOP >= 4).
+
+Consider terrain and minimum target size to determine required point density.  Steep terrain may cause shadowing effects due to perspective.
+
+Consider reflectivity of surface - lighter surfaces need less laser power.  Too high a power means intensity overflows on the reflection, which mess up the range - AGC should deal with this for large areas but it should be considered in planning, particularly for small bright targets on a generally darker background.  Assume 10% reflectivity is typical.
+
+Recommended to do a figure 8 loop at the start and end of the data acquisitions to make the IMU happy.  Need one at the end for reverse navigation processing.
+
+---------------------------
+
+= Processing =
 
 == Required items for processing ==
@@ -105 +110 @@
  * lever arm measurements
 
-= Processing =
 == Extraction ==
 
@@ -120 +124 @@
 See other pages on navigation processing as they cover this already.
 
+== General processing ==
+
+''Mark covered this better''
+
+-----------------------
 = QC =
 
@@ -180 +189 @@
  * comparisons against GCPs
    * requires the point cloud to be converted to a surface (
-