[GRASS-dev] [GRASS GIS] #3469: i.atcorr: Sentinel-2 support broken on some systems

[GRASS GIS]

#3469: i.atcorr: Sentinel-2 support broken on some systems
-------------------------+-------------------------
 Reporter:  sbl          |      Owner:  grass-dev@…
     Type:  defect       |     Status:  new
 Priority:  normal       |  Milestone:  7.4.0
Component:  Packaging    |    Version:  unspecified
 Keywords:  i.atcorr     |        CPU:  Unspecified
 Platform:  Unspecified  |
-------------------------+-------------------------
 It seems that Sentinel-2 functions in i.atcorr are effectively broken in
 some release packages and on some systems.

 The following installations have been reported to only return NULL values
 in output:
 * Ubuntu 16.04 with GRASS 7.4.0RC1 from UbuntuGIS-experimental
 * UBUNTU 14.04 with GRASS 7.4.0RC1 self compiled with gcc 5.4.1 (and
 older)
 * UBUNTU 14.04 with GRASS 7.5 self compiled with gcc 4.8
 * Windows 8.1 with GRASS 7.4.0RC1 and 7.5 daily from OSGeo4W

 However, the following systems produce reasonable output:
 * UBUNTU 16.04.3 LTS with GRASS 7.4 and 7.5 self compiled with gcc 5.4.0
 20160609 Ubuntu 5.4.0-6ubuntu1~16.04.5
 * Fedora 27 with GRASS 7.4.0RC1 and 7.5 self compiled with gcc 7.2.1
 20170915

 Test case below, test data attached to the ticket.

 {{{
 r.in.gdal input=dem.tif output=dem –o -–v --o
 r.in.gdal
 input=S2A_OPER_PRD_MSIL1C_PDMC_20160907T044118_R008_V20160905T104022_20160905T104245.B08.tif
 output=B08 -o -–v --o
 g.region -p raster=B08 align=B08
 i.atcorr -r input=B08 elevation=dem range=0,10000 output=test_atcorr
 rescale=0,10000 parameters=p6s.txt -–v --o

 }}}


 relevant compiler flags are:

 -g -Wall -Wextra -Wpedantic -Wshadow -Wno-sign-compare -fno-common
 -fexceptions -Werror=implicit-function-declaration -Wp,-D_FORTIFY_SOURCE=2
 -O3 -fno-fast-math

 -fno-fast-math might be important

 Finally, running i.atcorr through valgrind (on Fedora) gives lots of the
 following warnings, that according to MarkusM should be investigated:
 {{{
 ==14080== Conditional jump or move depends on uninitialised value(s)
 ==14080==    at 0x42B18D: os(float, float, float, float, float, float (&)
 [51][49], Gauss&, Altitude const&, GeomCond const&) (computations.cpp:831)
 ==14080==    by 0x42E9E3: atmref(float, float, float, float, float,
 OpticalAtmosProperties&, Gauss&, GeomCond const&, AerosolModel const&,
 Altitude const&) (computations.cpp:1408)
 ==14080==    by 0x42FCBC: discom(GeomCond const&, AtmosModel const&,
 AerosolModel const&, AerosolConcentration const&, Altitude const&, IWave
 const&) (computations.cpp:1654)
 ==14080==    by 0x40C032: init_6S(char*) (6s.cpp:100)
 ==14080==    by 0x405A3C: main (main.cpp:618)
 ...
 later on

 ==14080== Conditional jump or move depends on uninitialised value(s)
 ==14080==    at 0x42DED8: iso(float, float, float, float, float, float (&)
 [3], Gauss&, Altitude const&) (computations.cpp:1262)
 ==14080==    by 0x42F011: scatra(float, float, float, float, float,
 OpticalAtmosProperties&, Gauss&, GeomCond const&, Altitude const&)
 (computations.cpp:1578)
 ==14080==    by 0x42FD08: discom(GeomCond const&, AtmosModel const&,
 AerosolModel const&, AerosolConcentration const&, Altitude const&, IWave
 const&) (computations.cpp:1659)
 ==14080==    by 0x406882: pre_compute_h(float) (6s.cpp:148)
 ==14080==    by 0x406372: process_raster (main.cpp:369)
 ==14080==    by 0x406372: main (main.cpp:632)
 ...

 }}}

 For ML discussion see:
 https://lists.osgeo.org/pipermail/grass-user/2017-December/077545.html

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3469>
GRASS GIS <https://grass.osgeo.org>