8 April 1997 Contract OPP 89-22832 Office of Polar Programs National Science Foundation 4201 Wilson Blvd., Suite 755S Arlington, VA 22230 Attention: Mr. Frank Brier, Facilities Engineering Project Manager Subject: INPUT FROM THE SOUTH POLE SCIENTISTS ON THE SPSM ELECTRONICS SYSTEMS CONCEPTS REVIEW Per your request at the recent South Pole Station Modernization (SPSM) Electronics Systems Concepts Review Meeting (Allied Signal, 26-27 March 1997), attached please find input on the topics that ASA was tasked to obtain from South Pole scientists. ASA edited their input only slightly, to include in ALL CAPS the pertinent reference paragraph(s) in the Allied Signal document "Amundsen-Scott South Pole Station Redevelopment Project: Electronic Systems Major Systems Concepts, Definition, and Evaluation". This input reflects coordination of the scientists' responses by Dr. Robert Morse, Chair of the South Pole Users Committee (SPUC) and Dr. Robert Loewenstein, Chair of the Communications and Computing Working Group in the SPUC. They contacted and collated responses from the following South Pole scientists: Bill Trabucco, Tony Fraser-Smith, Pat Mock, George Papen, Tony Stark, Ellen Mosley-Thompson, Gonzalo Hernandez, and Ted Rosenberg, plus themselves. ASA thanks all of the South Pole scientists for their input on the SPSM Electronics Systems topics on such short notice and looks forward to their continuing participation in the ongoing discussions of the SPSM Project. Please request any further information required. Steven T. Kottmeier ASA Chief Scientist Attachment (1) As Stated cy: C.W. Sullivan, NSF/OPP Director E. Chiang, NSF/OPP Section Head, Polar Research Support D. Peacock, NSF/OPP Section Head, Antarctic Sciences Section J. Lynch, NSF/OPP Aeronomy and Astrophysics Sciences Program Manager D. Bresnahan, NSF/OPP Systems Manager S. Stephenson, NSF/OPP Research Support Manager A. Brown, NSF/OPP Manager, Specialized Support P. Smith, NSF/OPP Technology Development Manager D. Tupick, NSF/OPP Electronics Systems Coordinator J. Rand, NSF/OPP South Pole Engineering Projects Manager J. Marty, NSF/OPP South Pole Construction/O&M Coordinator -------------------------------------------------------------------------- --- SOUTH POLE SCIENTISTS INPUT TO SPSM ELECTRONICS SYSTEMS CONCEPTS REVIEW 8 April 1997 PARAGRAPH 3.3 GOES GROUND SYSTEMS IF0400 1. Acceptable EMI/RFI emissions. EMI susceptibility, EMI hardening Dark Sector EMI/RFI thresholds There is no magic number for EMI/RFI. Every experiment will have its own requirements and should be treated on a case by case basis. The fact that most existing experiments were able to successfully work with the meteor-trail radar in operation indicates that most current experiments are not particularly EMI sensitive. We cannot speak for all possible future experiments, but as a general policy, emissions from the new station should be kept as spectrally clean as possible using reasonable and moderate cost precautions. Any over-specification would be a waste of resources. The design discussion should focus on the noise derived from power lines, which will be the primary polluter. One note: The antennas for satellite communications at frequencies between 1 GHz and 18 GHz should be designed for low spillover and low sidelobes. This may require that these antennas be somewhat more expensive than would otherwise be the case. PARAGRAPH 3.7 SOUTH POLE TDRSS RELAY NETWORK IF1020 2. Projected Data Rates for TDRSS satellite relay network service, multiple user (150 MHz) We estimate that the data rates will grow to ~2 GByte/day over the next five years. However, we should note that we are concerned with more than just data rates. Connectivity, satellite availability, and reliable interactive access via internet is, in many ways, more important that super-high bandwidth, non-interactive connection links. No matter what bandwidth is achieved, new bandwidth intensive technologies will eat it up. A good initial goal should be T3 for both uplink and downlink. However, a clear upgrade path should be included in the planning document from the initial design because no matter what happens, people will need more bandwidth. PARAGRAPH 3.6 ATS-3/LES-9 GROUND SYSTEM IF0880 3. Historic Record of Sky Temperatures ATS-3/LES-9 ground systems No comment.... PARAGRAPH 3.12 GPS TIME RUBIDIUM FREQUENCY SYSTEM IF2020 4. GPS time-keeping. Should station provide? Centralized facility. good idea or not? Experimenters to provide specifications. Accuracy needed 10 ms, 1 ms, ...1 uS? Working Groups to suggest approaches. There is no scientific need to create a station-wide timing system. Having a station-wide time distribution system used to be a good idea. GPS has now become so inexpensive, however, that a distributed system seems pointless. The best solution is a low cost, station-wide NTP (network time protocol) added to the existing computer network. NTP will give sub-millisecond absolute time accuracy for network computers. Experiments needing time better than this should deal with it themselves. PARAGRAPH 3.15 METEOROLOGICAL SYSTEMS (FLIGHT SYSTEMS) IF2930 5. Science Meteorological Requirements --ASOS system beyond flight operations The standard met readings should be sufficient. PARAGRAPH 3.1 HIGH FREQUENCY ANTENNA SYSTEM IF0110 6. EMI from HF antenna systems? Again, look at on a case by case basis. PARAGRAPH 3.19 CATV (VDS) SYSTEMS IF3640 7. CATV(VDS) Systems, CCTV (entertainment) in station Allows for real time data acquisition We doubt if this is necessary at all. Given the ubiquity in digital systems, old analog systems will be obsolete for data displays. We should think in terms of the descendents of web browsers: digitial displays using LANs. PARAGRAPH 3.13 CABLE PLANT DISTRIBUTION SYSTEM IF2300 8. What about Local Area Network (LAN) structures? 100 Mb/s backbone, with local subnets. No real change from the committee's previous recommendations for the current station. PARAGRAPH 3.3 GOES GROUND SYSTEMS IF0400 3.6 ATS-3/LES-9 GROUND SYSTEM IF0880 3.7 SOUTH POLE TDRSS RELAY NETWORK IF1020 9. What about "connectivity", which allows science to be done "interactively", keeping the winter-over's emotionally connected with the experimenters at the home institutions. I quote from the 1996 SPUC report on Communications 1) 24 hour connectivity with the south pole. a) Continuous communications would support remote observing programs at the CARA facilities. b) The AMANDA and SPASE collaborations could move much their data analysis to machines at the pole, which would allow results to be obtained much more quickly. c) The window for interaction between CONUS and Pole will be widened, resulting in much more efficient interaction with winter-overs. d) The longer availability would allow better use of CONUS experts (such as software engineers). 2) Pursue acquisition of other satellites (GOES?) to complement the two we use now. 3) Emphasize connectivity convenience, times, and quality rather than very high bandwidth. While we could obtain more bandwidth with TDRS, TDRS does not provide the full-duplex connectivity described above. We think our money will be better spent to increase the cadre of GOES type satellites in the future and supply more bandwidth, satellite availability and performance with interactive, internet capable pathways.