My guess is that something unexpected is in the DIMAP file. Is it an original DIMAP file as distributed by SPOT or one of their distributors?

Hi Mari, Yes, it is an original DIMAP file from SPOT. See below for the top of the dimap file. I haven't used .sav files before - should I perhaps change something in some settings? I am using envi 4.7 & idl. Thanks, Liesbeth DIMAP SPOTView 0_0 / DVD 1 0_0-Kazakhstan_101014_T+X_192_257/8 SPOTView Kazakhstan Kazakhstan KZ Cnes 1986-2011 , Distribution Spot Image BAND_COMPOSITE GEOTIFF 522417.50 5088305.96 75.289240 45.947958 522417.50 5025509.83 75.286344 45.382745 483920.00 5036949.60 74.794232 45.485891

My guess is you cannot calibrate this data because it is a SPOTVIEW product and not a 1A or 2A product. SPOTVIEW DIM files do not contain the calibration parameters that are necessary to convert the data to radiance. You would need these tags in the DIM for each band: 0.000000 3.246594

That makes sence, the product is indeed orthorectified, so 2B. Although the physical gain and bias values are in the .dim file, but perhaps something else in the .dim file is different? DIMAP SPOTView 0_0 / DVD 1 0_0-Kazakhstan_101014_T+X_192_257/8 SPOTView Kazakhstan Kazakhstan KZ Cnes 1986-2011 , Distribution Spot Image BAND_COMPOSITE GEOTIFF 522417.50 5088305.96 75.289240 45.947958 522417.50 5025509.83 75.286344 45.382745 483920.00 5036949.60 74.794232 45.485891 483920.00 5037078.21 74.794228 45.487048 500970.00 5094662.50 75.012528 46.005535 485304101-0_0 SPOTVIEW 2011-02-08T12:03:03.000000 Spot Image EPSG epsg:32643 PROJECTED WGS 84 / UTM zone 43N CELL 0 483920 5094670 2.5 2.5 15399 30200 3 8 I BYTE ORTHO T+X Basic 1 2 3 0 NODATA 0 0 0 1.000000 255.000000 134.493464 31.773383 75.000000 181.000000 1 1.000000 255.000000 156.878755 38.524769 64.000000 223.000000 2 1.000000 255.000000 118.278448 33.699880 59.000000 169.000000 3 XS1 W.M-2.ST-1.uM-1 0.000000 1.999252 3 XS2 W.M-2.ST-1.uM-1 0.000000 2.781212 2 XS3 W.M-2.ST-1.uM-1 0.000000 2.971476 1 SCENE 51922571010140610582A SCENE HRG2 A 192257 8 2010-10-14 06:11:05 B_W SPOT 5 HRG 2 1A 12.070496 10.587387 169.665745 35.810113 NOINFO 1 7 2.804000 2 7 2.798000 3 7 2.798000 SCENE 51922571010140610582B SCENE HRG2 B 192257 8 2010-10-14 06:11:05 B_W SPOT 5 HRG 2 1A 12.070779 10.587387 169.665685 35.810265 NOINFO 1 7 2.804000 2 7 2.798000 3 7 2.798000 SCENE 51922571010140611002J SCENE HRG2 J 192257 8 2010-10-14 06:11:07 Colour SPOT 5 HRG 2 1A 12.050902 10.587387 169.676092 35.810471 NOINFO 1 7 2.804000 2 7 2.798000 3 7 2.798000

Unfortunately, there are some differences between the SPOTView dimap tags and those of standard SPOT DIMAP. There are some duplicate tags that are not present in most of the metadata I have worked with for the 4-band 1A and 2A datasets. This would require some updating to the code. However, it is not all that difficult to calibrate the bands maually using Band Math.

I updated the spot_calibrate file to ignore some duplicate tags. You might give it a try.

I updated the spot_calibrate code to ignore some duplicate tags. You might download the new file and give it a try.

I updated the spot_calibrate code to ignore some duplicate tags. You might download the new file and give it a try.

I updated the spot_calibrate code to ignore some duplicate tags. You might download the new file and give it a try.

Hi all, MarimM thanks for creating the SPOT calibrate tool for ENVI. It looks very straightforward to use; however I was not able to do that yet since ENVI 4.8 stops responding after a while. My imagery is level3 which means that XML file is also different from level1 and level2 I assume. Is there a way of overcoming this problem? Best regards Dimitris

Hi, This is for ENVI 4.8 64-bit. I tried to run the spot calibrate tool with the .dim of an image and ENVI just freezes. This is the metadata: CPO44V20P 2011-12-14 Spot Image 2011-03-07 16:01:52 SPOT 4 HRVIR 2 Colour 619-318 4 1A ORTHO Basic I 1 XS3 1.338000 0.000000 W.M-2.ST-1.uM-1 NEAREST XS3 1.338000 0.000000 W.M-2.ST-1.uM-1 XS2 1.769488 0.000000 W.M-2.ST-1.uM-1 XS1 1.912514 0.000000 W.M-2.ST-1.uM-1 The image came inside a folder called "SPVIEW__2011_0" and when I opened it in ENVI, the available band list window showed its name of SPOTVIEW. I'm not sure if this DIMAP file is still compatible with your script? Or how do I make it unfreeze and proceed? Thanks a lot! O.W.

My guess is that the dimap format has changed again so the tool is unable to parse it. There is an easy solution though. You know what the gain/offset values are in your metadata. You can use ENVI's Apply gain and Offset tool using the *inverse* of these values which will calibrate the data to radiance.