<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">Hi, <DIV><BR class="khtml-block-placeholder"></DIV><DIV>I'm creating an instrument kernel for the IES instrument on the Rosetta spacecraft. It is similar to the PEPE instrument on Deep Space 1. I read the SPICE instrument kernel tutorial which describes how to write the IK such that the data could be accessed through the getfov function. However, because of the design of the IES instrument, this would result in a rectangular shaped fov with a boresight vector and only two boundary vectors instead of four. This is because the rectangular instrument fov wraps around to form a cylinder so that the two upper boundary vectors are equivalent and the two lower boundary vectors are also equivalent. I was looking at the PEPE IK and noticed that it was written such that the boundaries of each bin are defined by the respective bin id, a bin lower boundary and a bin upper boundary. This seems much more appropriate for the IES instrument. Which one is the correct format for the IES instrument kernel? Also, should the vectors describing the fov be in the IES frame? </DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Thanks</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><DIV> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">~~~~~~~~~~~~~~~~~~~~~~~</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Aimee Mostella<SPAN class="Apple-converted-space"> </SPAN></FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Research Analyst</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Southwest Research Institute</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Space Science Division</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">(210) 522-6735</FONT></P> </DIV><BR></DIV></BODY></HTML>