Richard contacted Gary with a query regarding azgcorr versions (expired again). Noted website was out of date too.

This has been an ongoing task since around April.

Contacted by Chris Hecker (also previously asked about azgcorr versions in #38). Full email below, but the key points are:

1. I want to use the ARSF/NERC LIDAR data that was recorded simultaneously with the hyperspectral data to improved geocorrection results. The data I want to correct are Eagle/Hawk data strips. The LIDAR data comes as point clouds in files like "Str_287.all". Can these point clouds be read directly into azgcorr (as what is referred to as an "external file") or do I need to use another software (e.g. SCOP++) to make regular gridded altitude data first?
2. For the LIDAR data, I presume that I wont need any geoid - ellipsoid correction parameter, since aircraft navigation data as well as airborne LIDAR are both based on DGPS heights above WGS84 ellipsoid. Is that correct?
3. I saw that there are a lot of special CASI options mentioned in the manual. Are there any for the SPECIM sensor in this version already and where would I find a list of these options?
4. Now here comes the tricky one:

   In the help file there is the option -E which allows the preprocessing of the LIDAR data cloud to new coordinates. Since all our basemaps are in European datum 1950, I wanted to pre-process the LIDAR cloud to this datum as well.
   Currently the data is in the standard format (UTM zone 30, WGS84) with xcoodrinate including the UTMzone as a prefix.
   The output datum is again UTM zone 30 with International ellipsoid and the following datum parameters dx=-87 dy=-98 dz=-121. no rotational parameters are known to me.
   
   So I tried the following AZGcorr statement:
   azgcorr -ELpt f1 x -d7 0 -87 -98 -121 0 0 0 0 -mUTMZ 30 -e Str_287.all
   
   Which to my knowledge should have given me a properly refernced data cloud for my UTM / ED50 system. I can see from the coordinates that are displayed during the processing that it is not going OK. The conversion of the x coordinate to the longitude value is already going wrong. I also noticed that the central meridian (in this case -0.0396 but changing with each time azgcorr is run ) doesnt make any sense. Am I doing something wrong or is this a bug? I am running azgcorr v. 4.8.3 on a 486pc-linux system.
   

Full email:

Hi Mike;
I started to work myself through the various manuals and LINUX version help file of azgcorr.
I have some questions regarding the processing. Maybe you can help me out with this. I am sure they (i.e. the first three) are pretty straight forward for you.

A) I want to use the ARSF/NERC LIDAR data that was recorded simultaneously with the hyperspectral data to improved geocorrection results. The data I want to correct are Eagle/Hawk data strips. The LIDAR data comes as point clouds in files like "Str_287.all". Can these point clouds be read directly into azgcorr (as what is referred to as an "external file") or do I need to use another software (e.g. SCOP++) to make regular gridded altitude data first?

B) For the LIDAR data, I presume that I wont need any geoid - ellipsoid correction parameter, since aircraft navigation data as well as airborne LIDAR are both based on DGPS heights above WGS84 ellipsoid. Is that correct?

C) I saw that there are a lot of special CASI options mentioned in the manual. Are there any for the SPECIM sensor in this version already and where would I find a list of these options?

D) Now here comes the tricky one:
In the help file there is the option -E which allows the preprocessing of the LIDAR data cloud to new coordinates. Since all our basemaps are in European datum 1950, I wanted to pre-process the LIDAR cloud to this datum as well.
Currently the data is in the standard format (UTM zone 30, WGS84) with xcoodrinate including the UTMzone as a prefix.
The output datum is again UTM zone 30 with International ellipsoid and the following datum parameters dx=-87 dy=-98 dz=-121. no rotational parameters are known to me.

So I tried the following AZGcorr statement:
azgcorr -ELpt f1 x -d7 0 -87 -98 -121 0 0 0 0 -mUTMZ 30 -e Str_287.all

Which to my knowledge should have given me a properly refernced data cloud for my UTM / ED50 system. I can see from the coordinates that are displayed during the processing that it is not going OK. The conversion of the x coordinate to the longitude value is already going wrong. I also noticed that the central meridian (in this case -0.0396 but changing with each time azgcorr is run ) doesnt make any sense. Am I doing something wrong or is this a bug? I am running azgcorr v. 4.8.3 on a 486pc-linux system.
Below I copy a screendump.

Thanks for the help,

Chris

His dump:

hecker@x7:~/in$ azgcorr -ELpt f1 x -d7 0 -87 -98 -121 0 0 0 0 -mUTMZ 30 -e Str_287.all
 
-----------------------------------------------------------------------
azgcorr  -- ver: 4.8.3-lin Jun 12 2007   (C) Azimuth Systems UK 1996, 2007
 

DEM pre processing...
 
Initialised transform for point cloud to WGS84 geogs...
 
Projection and datum shift details initialised....
Spheroid name: WGS84
  semi-major: 6378137.00000  semi-minor: 6356752.31425  e^2: 0.006694380 1/f: 29
8.257223563
Projection name: UTM
  origin  lat: 0.0000  long (central meridian) : -0.0396
  grid coords at origin  easting: 500000.00  northing: 0.00
  scale factor: 0.99960000  hemisphere: north
Datum shift name: none
 
Initialised transform for point cloud WGS84 geogs to local datum and projection.
..
 
Projection and datum shift details initialised....
Spheroid name: INTERN
  semi-major: 6378388.00000  semi-minor: 6356911.94613  e^2: 0.006722670 1/f: 29
7.000000000
Projection name: UTM
  origin  lat: 0.0000  long (central meridian) : -3.0000
  grid coords at origin  easting: 500000.00  northing: 0.00
  scale factor: 0.99960000  hemisphere: north
Datum shift name: SING
  old spheroid name: INTERN
  semi-major: 6378388.00000  semi-minor: 6356911.94613  e^2: 0.006722670 1/f: 29
7.000000000
  dx: -87.0000 dy: -98.0000 dz: -121.0000 metres  sc: 0.000000  ppm
  rx: 0.0000 ry: 0.0000 rz: 0.0000 secs
 

old x: 593792.77 y: 4095708.38  z: 131.270 lat: 37.0028547 lng: 1.0145276
new x: 857185.96 y: 4102748.87 z: -12.407
old x: 593792.77 y: 4095708.39  z: 131.310 lat: 37.0028548 lng: 1.0145276
new x: 857185.96 y: 4102748.88 z: -12.367
old x: 593792.79 y: 4095707.83  z: 131.270 lat: 37.0028497 lng: 1.0145278
new x: 857186.00 y: 4102748.32 z: -12.407
old x: 593792.79 y: 4095707.84  z: 131.290 lat: 37.0028498 lng: 1.0145278
new x: 857186.00 y: 4102748.33 z: -12.387
old x: 593792.82 y: 4095707.10  z: 131.300 lat: 37.0028432 lng: 1.0145280
new x: 857186.05 y: 4102747.59 z: -12.377
old x: 593792.82 y: 4095707.12  z: 131.340 lat: 37.0028433 lng: 1.0145280
new x: 857186.05 y: 4102747.61 z: -12.337
old x: 593792.91 y: 4095706.78  z: 131.310 lat: 37.0028403 lng: 1.0145290
new x: 857186.15 y: 4102747.27 z: -12.367
old x: 593792.90 y: 4095706.80  z: 131.370 lat: 37.0028404 lng: 1.0145289
new x: 857186.14 y: 4102747.29 z: -12.307
 
file: Str_287.all  converted points: 3910381
 
End of DEM run