This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
Hi HansPeter- > Institution: EUMETSAT > Package Version: 2.0RC3 > Operating System: os.name:Windows XP; os.arch:x86; os.version:5.1; > Hardware Information: java.vendor:Sun Microsystems Inc.; > java.version:1.5.0_06; java.home:C:\\Program Files\\IDV_2.0RC3\\jre; > j3d.version:1.4.0 fcs (build11); j3d.vendor:Sun Microsystems, Inc.; > j3d.renderer:OpenGL; > Inquiry: 2.0RC3 > > I am somewhat at issue with the Data Type default on the Data Chooser widgets > when accessing M8 channels. The default for all channels is Brightness. That > might > be fine for VIS and NIR channels (0.6, 0.8, 1.6) although radiance would be > preferred. > For the IR channels there is a very strong preference to have them displayed > in the > temperature domain.. I.e. presently whenever selecting a couple of IR > channels you > have to reset the Data Type box to Temperature for each channel. This is > rather > inconvenient. > In the imagedefaults.xml file, you can specified the preferred unit on a per dataset basis. So, for your case, you could modify your existing one to be: <default name="193.17.10.4" key="LATLON" place="CENTER" loc="0 0" unit="RAD" user="XX" proj="XXXX"/> to set the predominantly default to Radiance (or use TEMP for temp to be the default). Currently, there is no way to specify a particular unit for a particular band in the image. > I would see 2 solutions to this: > 1. Keep the last used Data Type when a new channel is selected. Since each band has it's own set of data types, right now, when a new band is selected, the list of data types is updated and the preferred band specified in the imagedefaults file is selected. That's why it always changes to Brightness since that is the system default. Making the change above will set the default to be Radiance. > 2. (preferred) default to Temperature for IR channels and Radiance for > VIS/NIR channels Except for parsing the description which is defined in the SATBANDS, I don't really know what band is IR for any given satellite or AREA file. In reality, all I really an ever rely on is that I have a band number, not a description. The only thing I can think of is modifying the imagedefaults unit specification to be something like: unit="RAD;TEMP:1,3,5" which would set the default for most bands to be RAD, but for bands 1,3 and 5, the default would be TEMP (I'm just making up numbers for the example - far from reality). I'm not sure I want to modify the code to handle this for the 2.0 release (since we are supposed to be in a new development code freeze), but could put this on the plate for a future release. What do you think of this option? > How does this sound? Don Murray Ticket Details =================== Ticket ID: MVI-449737 Department: Support IDV Priority: Normal Status: Open