From krehbiel@ibis.nmt.edu Fri Nov 5 20:20:42 1999 From: Paul Krehbiel Subject: Re: CSU-CHILL sites near Bethune To: pat@lab.chill.colostate.edu Date: Fri, 5 Nov 1999 13:12:02 -0700 (MST) Cc: ljmill@ncar.ucar.edu (L. Jay Miller), rutledge@atmos.colostate.ed (Steve Rutledge), bringi@longs.lance.colostate.edu (Bringi), Llyle.Barker@noaa.gov (Llyle Barker) Pat and all: Yesterday after talking with you about the Bethune-Burlington area for CHILL, I sat down again with Topo USA and made maps of two possible arrangements of the triple Doppler network, based on CHILL being A) in the Bethune area, and B) at Burlington airport, just to see how they looked. The maps are on the current version of our web page on STEPS, at www.lightning.nmt.edu/nmt_lms/STEPS_lma.html . The overview map at the top of the page shows the A) option (Bethune) as a green triangle and the B) option (Burlington Airport) as a blue triangle. Further down the page is an expanded map of the Bethune-Burlington area showing the possible CHILL sites in more detail. There is a relatively high area about 3 miles south of Bethune, which shows up as a small region above the 4100' contour. To do the topographic profiling I put CHILL_A location there. It is about 1/2 to 3/4 mile south of one of the weather spotters, 7KC102, whose name is the one I didn't have. (The other spotters in the area are also on the map.) CHILL_B is at an arbitrary location on the Burlington Airport area. I arbitrarily put S_POL at the north end of the N-S leg of US 36 east of Idalia for the A option, and at the south end of the leg for the B option. This gives topographic profiles and baselines indicated in the profile plots at the bottom of the web page. The A (green) option has triple Doppler legs of 64, 64, and 55 km, with the CHILL-S_POL leg being the shortest. For the B (blue) option, the legs are 61, 51, and 52 km, with the S_POL-NWS leg being the longest. The profiles show that in the CHILL_A option, being on top of a local `hill', would have a clear view both to the north and south, with the terrain gradually sloping downward in both directions. One would have close to line-of-sight with Goodland. In the B option, CHILL would be about 60 m lower in altitude and be looking across more or less flat terrain for about 10 km to the north, and over a slight (15m) rise to east. The latter would affect the line-of-sight to Goodland. If you want some close ground blockage to cut out ground returns at a further distance, the B option would be good, but its baselines are shorter. If one wants a more clear view, the A option would be better. For communication of data between CHILL and NWS-Goodland, A would be better, but either option could require a relay, in which case there is no difference. We may also require a relay to get the lightning mapping communications into Goodland, and I had talked with Scott Mentzer about whether we could use the Coop Grain Elevator in Goodland for this. One way or the other, one should be able to do wireless modem or ethernet from CHILL to the Goodland NWS office. Another question is whether there would want to be wireless communications with S_POL. This could be useful if we are able to tie into the T1 fiber optic cable at or near the S_POL site. Their is a grain elevator at Idalia which would provide a relay point for wireless communications to S_POL, if the elevator is available. The topographic data show that the land along the north-south leg of US 36 is almost perfectly flat, with a very gentle upward slope from east to west. S_POL could go almost anywhere along this stretch of the highway, or to the east or west of the highway, depending on site availability and what one wants for the triple Doppler consideration. Paul Krehbiel -- Paul Krehbiel Voice : 505-835-5215 Physics Department FAX : 505-835-5707 New Mexico Tech email: krehbiel@ibis.nmt.edu Socorro, NM 87801