computing the absolute orthophoto and DEM

Once you have successfully run spymicmac.register.register_ortho(), you will have an orientation folder, Ori-TerrainFirstPass 1. This is the folder to pass to Malt:

mm3d Malt Ortho "OIS.*tif" TerrainFirstPass DirMEC=MEC-Malt NbVI=2 MasqImGlob=filtre.tif ZoomF=1 DefCor=0 CostTrans=1 EZA=1

Just like with the computing the relative orthophoto step, once this command finishes, you will have two new directories: MEC-Malt and Ortho-MEC-Malt. The DEM and associated correlation masks are found in MEC-Malt, while the orthophotos are found in Ortho-MEC-Malt.

Depending on the scale of your images and how many you are using, you will probably need to mosaic the tiles of the DEM, and possibly the correlation masks 2:

cd MEC-Malt
mosaic_micmac_tiles.py -filename Z_Num9_DeZoom1_STD-Malt
mosaic_micmac_tiles.py -filename Correl_STD-MALT_Num_8

Once the tiles have been mosaicked, you can also run post_process_micmac.sh to apply the AutoMask and add a CRS to the DEM.

creating the orthomosaic using Tawny

Just like with the computing the relative orthophoto step, the orthoimages are not mosaicked - they are just the individual images orthorectified using the extracted DEM - you’ll need to run Tawny again to mosaic the images:

mm3d Tawny Ortho-MEC-Malt Out=Orthophotomosaic.tif RadiomEgal=0

Again, we are using RadiomEgal=0 to use the images as-is, rather than attempting to balance the radiometry (as this can lead to undesirable results). Finally, you might need to re-combine the image tiles, depending on how large they are:

cd Ortho-MEC-Malt
mosaic_micmac_tiles.py -filename Orthophotomosaic

At this point, you should have a finished DEM and orthomosaic. You may want to check the accuracy of your DEM by co-registering it to a DEM of known quality. You may also wish to remove residual doming effects using mm3d PostProc Banana.

You can also run post_process_micmac.sh to apply the AutoMask to the DEM and georeference the correlation mask:

cd MEC-Malt
post_process_micmac.sh -z "8 +north" -n Block1

1

If you are running spymicmac.register.register_ortho() with block set to a value (e.g., -b 1), this will be Ori-TerrainFirstPass_block1. You should also change DirMEC to a different name, (e.g., MEC-Malt_block1), otherwise it will be overwritten with each new block that you run.

2

Note that in some cases with very large image blocks, the final steps will actually be Z_Num10_DeZoom1_STD-MALT and Correl_STD-MALT_Num_9 - it’s probably a good idea to check this!