SfS some problem with the option "--sun-position <string>"

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dingxin liu

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Sep 14, 2022, 10:20:35 PMSep 14
to Ames Stereo Pipeline Support
I want to use the tool of SfS to refine the DEM obtain from ASP.  The camera model is a pinhole, so the tool cannot read the sun's position from the image. When I use the command of "sfs -i run_noCS/out-crop-DEM_fillhole_600.tif --max-iterations 10 -o sfs_test1/run --reflectance-type 0 --smoothness-weight 0.04 --initial-dem-constraint-weight 0.001 -t pinhole 00749_0005_gray_corrected.tif 00749_0005_gray_corrected.tsai"  , it reports the error of ''Could not read sun positions from list or from camera model files." How should I  fix the problem?  
The ASP book explains the option "--sun-position <string>"  A file having on each line an image name and three values in double precision specifying the Sun position in ECEF coordinates. 
(1)The image is from Mars, so if I want to use the SfS, what is the definition of ECEF? Whether it is the coordinates in the solid system?
(2) If so, What are the specific units of the three parameters input? (m, km, or au?)
The more detail is in my log.
run-log-sfs-09-14-2021-38718.txt

Alexandrov, Oleg (ARC-TI)[KBR Wyle Services, LLC]

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Sep 14, 2022, 11:06:40 PMSep 14
to dingxin liu, Ames Stereo Pipeline Support
The SfS program is a research code, and while I was able to get plausible results for Mars, so craters show up where they should, the produced terrain is not quite right. The issue seems to be that for Mars one needs a fancy reflection model, given its atmosphere, and the model coefficients depend on the location, as Mars's geology is very diverse. You can try experimenting with the Hapke model (see the doc), but there's a risk you may not be successful. 

You will also need to find the right smoothness weight, for which one should experiment by multiplying it/dividing it by factors of 10 a few times.

> (1)The image is from Mars, so if I want to use the SfS, what is the definition of ECEF? Whether it is the coordinates in the solid system?

ECEF has the origin at the planet center.

(2) If so, What are the specific units of the three parameters input? (m, km, or au?)

The units are in meters. 

I now expanded the doc to explain about ECEF and units.

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