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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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.
David, I provide a calibration block in the image (in the unused portion of the GINI header) that is used to obtain the image calibration bar values. I created a section of code in $GEMPAK/source/gemlib/im/imgi2gm.f with: C C* Get calibration Block if it exists. C* Currently, only Unidata calibrations exist, using C* Word 47 = 128 C* to signal that a calibration block is present. C At present the format is the number of calibration ranges N, followed by N * 4 values where each set of 4 represents the pixel min, max and data value min max they corespond to. Recall that these are created from the Level 3 images which are already sampled to a limited number of data ranges. Steve Chiswell >From: davidw <address@hidden> >Organization: UCAR/Unidata >Keywords: 200210232017.g9NKHAp23974 > >This is a multi-part message in MIME format > >---------19c36ed319c36ed3 >Content-Type: text/plain; charset=iso-8859-1 >Content-Transfer-Encoding: quoted-printable > >Hi, > > I'm working with the NEXRAD composite images that you generate in GINI for= >mat. Is there a method of converting the raw values to dBZ? = > > > Thanks for any info. > > >---------19c36ed319c36ed3 >Content-Type: text/html; charset=iso-8859-1 >Content-Transfer-Encoding: quoted-printable > ><HTML> ><HEAD> ><META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; charset=3Dwindows-1= >252"> ><META NAME=3D"Generator" CONTENT=3D"Internet Assistant for Word Version 3.0= >"> ></HEAD> ><BODY> > ><FONT SIZE=3D2><P>Hi,</P> > ><P> I'm working with the NEXRAD composite images that you generate in GINI = >format. Is there a method of converting the raw values to dBZ? </P> > ><P> Thanks for any info.</P> > ><P> </P></FONT></BODY> ></HTML> > >---------19c36ed319c36ed3-- >