Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Fri, 26 Apr 91 01:39:08 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 26 Apr 91 01:39:02 -0400 (EDT) Subject: SPACE Digest V13 #462 SPACE Digest Volume 13 : Issue 462 Today's Topics: Saturn V and Design Reuse: Saturn VI? Re: Energia (was Re: Saturn V blueprints) Re: Saturn V and the ALS Re: Saturn V vs. ALS SOLAR TERRESTRIAL FORECAST AND REVIEW Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 25 Apr 91 21:08:55 GMT From: mips!samsung!cs.utexas.edu!cse!texas!csl.dl.nec.com!baker@apple.com (Larry Baker) Subject: Saturn V and Design Reuse: Saturn VI? One of the things that has always been true in complicated engineering problems is that, for reliability in a design, you have to start with one that works well, and improve it incrementally. There are generally very few "revolutionary" new designs that work reliably or cheaply early on. It takes lots of time and experience to get to the point where a particurlar system is well understood. A key part of the problem, of course, is getting to the point where you have a design that works reasonably well. The Saturn V represents, to me, the fruition of such an effort: a design that works well. But it stands to reason that design *practice*, *experience* and *technology* has improved dramitically in the past 30 some-odd years: finite element modeling, materials sciences, electronics, robotics (for manufacturing), computers, real-time software systems, fluid-code simulations for aerodynamics and engine models. My question -- and, I guess, my point -- is this: Why rebuild the Saturn V? Why not take the Saturn V design and incrementally improve it, with the advantages of 30 years' improvement in practice, experience and technology? Don't rebuild it. Don't start over. Improve the existing design? Saturn VI? This cannot be a new idea. -- Larry Baker NEC America C&C Software Laboratories, Irving (near Dallas), TX baker@texas.csl.dl.nec.com cs.utexas.edu!necssd!baker ------------------------------ Date: 25 Apr 91 00:17:21 GMT From: hub.ucsb.edu!ucsbuxa!3001crad@ucsd.edu (Charles Frank Radley) Subject: Re: Energia (was Re: Saturn V blueprints) In article <1991Apr24.060803.22484@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: At last we get to the heart of the matter. NASA will buy launchers from wherever the Congress / Administration instructs them to. Currently isit US government policy to "Buy American" and that policy shows no sign of changing. >In article <10797@hub.ucsb.edu> 3001crad@ucsbuxa.ucsb.edu (Charles Frank Radley) writes: >>Federal law prohibits The Us Government ( including NASA ) >>from purchasing launches on foreign launch vehicles. >Inconsequential. The same organization that would have to approve and >fund such an effort -- Congress -- can change those laws any time it >wants to. >-- >And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology >"beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 25 Apr 91 16:46:07 GMT From: news-server.csri.toronto.edu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Saturn V and the ALS In article <1991Apr24.190403.27151@en.ecn.purdue.edu> irvine@en.ecn.purdue.edu (/dev/null) writes: >I will state this again: Re tooling and parts finding for the old >Saturn V is a nightmare that does not give us much benefit besides >a rocket (A research program, we get a rocket and discover new things >we did not know before - always beneficial). The point of this exercise is a launcher, not research. Research does not produce good launchers, based on the (admittedly limited) experience with it to date. I don't think anyone will dispute that reviving the Saturn V is not going to advance launcher technology. It's not supposed to. >If we don't try to become better, we only go backwards! >(Many other nations would thank us for this) The Europeans thank you profusely for not coming through on the shuttle's promises; Arianespace has made a bundle out of your failure. If you wish to repeat the mistake, I'm sure they'll thank you for it. You *are* going backwards. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 25 Apr 91 19:19:29 GMT From: usc!elroy.jpl.nasa.gov!sdd.hp.com!spool.mu.edu!cs.umn.edu!ariel.unm.edu!nmsu!charon!bwebber@apple.com (Bill Webber) Subject: Re: Saturn V vs. ALS In article <1991Apr24.234249.10940@nntp-server.caltech.edu> krs@dullea.ipac.caltech.edu (Karl Stapelfeldt) writes: > > The problem with resurrecting the Saturn V today is the same >same problem that caused the launcher to go out of production in the >1970s : It is just too damn big for our current needs. The only >viable Saturn V payload in the next 10 years would be Space Station >hardware; the Saturn V is so big that after 1-2 such missions we wouldn't >need it again. It clearly is not worth rebuilding the Saturn V with >this kind of expected utilization. I disagree. What about the possibility that once a large and reliable launcher is proven that more things will be created to fill the available capacity? You can't set up a market until somebody takes the risk and provides the infrastructure. Usually that somebody is the govt, because most corporate types don't have the guts to fund new risky ventures like the old days. Too much worrying about the bottom line on a 1/4ly basis and kissing up to the stockholders. Buying stock in a company used to mean accepting the ups and downs of that business. Now if someone doesn't make that 15 to 20 percent annually, they cash out and move on. Priorities in this country are skewed away from innovation and risk. Using a larger launcher would give a needed foothold to companies that would not normally risk space industry development. Give it (the industry) a 15 year tax incentives program, and see how fast they 'get it up'. Just my views, I suppose, so buyer beware. K.MacArthur ------------------------------ Date: Thu, 25 Apr 91 15:26:48 MDT From: oler <@BITNET.CC.CMU.EDU:oler@HG.ULeth.CA> (CARY OLER) Subject: SOLAR TERRESTRIAL FORECAST AND REVIEW X-St-Vmsmail-To: st%"space+@andrew.cmu.edu" --- SOLAR TERRESTRIAL FORECAST AND REVIEW --- April 25 to May 04 , 1991 Report Based In-Part from Data Obtained from the Space Environment Services Center Boulder Colorado -------- SOLAR TERRESTRIAL REVIEW FOR 18 APRIL TO 24 APRIL Solar activity has been very low to high over the past week. The most notable day of the week was 20 April when a large class X1.0/3N flare erupted from Region 6583 at a location of N08W50. The flare was associated with a moderate to strong Type IV sweep, and was of long duration. The flare immediately caused concerns that proton and geomagnetic activity might again become enhanced. However, neither materialized. Only a weak proton enhancement was observed, but proton levels never exceeded the event threshold. A minor to major geomagnetic storm was also predicted, but failed to materialize. Since then, solar indices have been dropping dramatically. The solar flux has dropped to a value of 135 on 24 April, which is the lowest levels observed since 23 June, 1990. The sunspot number for 24 April has fallen to a low value of 72. The background x-ray flux has also dropped dramatically, from a value of C1.0 for 23 April to a class B6.3 for 24 April. Values this low have not been observed for many months. In fact, the observable solar disk is so quiet at the present time, that only low-level C-class flares and subflares have been observed. There is practically no chance for M-class flaring from the very simple spot groups currently on the solar disk. Geomagnetic activity has been quiet to unsettled this week. A period of unsettled to active conditions was observed on 18 and 19 April, and again late in the period on 24 April. The latter was preceded by a sudden magnetic impulse of 33 gammas, marking the leading portion of an interplanetary shock. The origin of this shock is uncertain. Auroral activity was most active on the evenings of 19 April and 24 April. Occassional periods of moderate activity were observed over the high latitude regions. The activity was limited to the high latitudes. HF propagation conditions have been normal to above normal throughout most of the week. No serious degradation in propagation quality occurred, despite the potential storm warning flags that were up earlier this week due the major X-class flare. SHORT TERM SOLAR TERRESTRIAL FORECAST Solar indices are expected to bottom out within the next couple of days. No major flares or minor M-class flares are expected until new active regions rotate back into view around the eastern limb. The next region expected to rotate into view which may be capable of producing M-class flaring is old Region 6566, which is due to return around 28 April. There are a couple of moderately large coronal holes which may begin influencing terrestrial magnetic activity anytime near 27/28 April. Generally unsettled geomagnetic conditions are expected on or near these dates until the 01 or 02 May when a return to quieter conditions is expected. High latitude regions are expected to experience periods of active conditions. There is also a slight risk for some isolated substorm periods over the high latitude regions with this activity, although no significant storming is expected. Middle and low latitudes should remain generally unsettled during these periods. Auroral activity is expected to become visible over the northerly middle latitudes on 27 or 28 April in response to enhanced solar corpuscular emissions from the coronal holes. High latitudes are expected to experience generally moderate levels of activity with a slight risk for isolated brief periods of high auroral activity in regions within the auroral zone. However, generally, only moderate levels of activity are forecasted over the high latitudes. Lunar phase will interfere with attempts to view auroral activity this week. HF propagation conditions have been above normal over the last several days (up until 24 April). Higher than normal MUFs and stable ionospheric conditions were the main contributors to quality of propagation. However, the low solar indices have begun decreasing MUFs as of late. Additionally, increased geomagnetic activity and an expected return to generally unsettled geomagnetic conditions on the 27/28 of April should keep HF propagation conditions at near normal levels for the remainder of this week. Periods of increased signal fading, noise and some distortion are possible from 27/28 April through to 01 or 02 May during the local evening hours. VHF propagation conditions are expected to remain near normal throughout the week. High latitudes may have a limited opportunity to experience some auroral backscatter communications, although these conditions are expected to be limited to the high latitude or northerly middle latitude regions. SUMMARY OF ALL ACTIVE REGIONS VISIBLE ON THE SOLAR DISK AS OF 25 APRIL Region # Location LO Area Class LL Spots Magnetic Type -------- -------- --- ---- ----- -- ----- ------------- 6593 S11W59 189 0180 CSO 07 006 BETA 6596 S21W52 182 0000 AXX 00 001 ALPHA 6597 S21W46 176 0030 BXO 04 005 BETA 6602 S23W66 196 0000 AXX 00 001 ALPHA 6603 S29W12 142 0060 BXO 05 009 BETA NOTES: Area is in million square kilometers. Angular extent (LL) and solar longitude (LO) are in degree's. For more information regarding the terminology used above, request the Glossary of Solar Terrestrial Terms from: "oler@hg.uleth.ca". H-ALPHA PLAGES WITHOUT SPOTS. LOCATIONS VALID AS OF 00:00 UT ON 25 APRIL REGION LOCATION LO COMMENTS (IF ANY) ------ -------- --- ------------------------------- 6587 S22W89 219 NONE 6598 S08W77 207 6599 S15W88 218 6600 S13W72 202 6601 S19W29 159 ACTIVE REGIONS DUE TO RETURN BETWEEN 25 APRIL AND 27 APRIL Region Latitude Longitude (Helio.) ------ -------- --------- 6565 N10 030 6572 S20 026 NOTES: For definitions regarding the above, request the "Glossary of Solar Terrestrial Terms" from "oler@hg.uleth.ca". GRAPHICAL ANALYSIS OF RECENT PLANETARY (GLOBAL) GEOMAGNETIC ACTIVITY Cumulative Geomagnetic Activity History Peak Planetary Geomagnetic Activity during the past 96 hours ____________________________________________________________________ | EXTREMELY SEVERE | | | | | HIGH | | VERY SEVERE STORM | | | | | HIGH | | SEVERE STORM | | | | | MODERATE | | MAJOR STORM | | | | | LOW - MOD. | | MINOR STORM | | | | | LOW | | VERY ACTIVE | | | | *| NONE | | ACTIVE | | *** | * | * **| NONE | | UNSETTLED | ******|* ***** | *****|********| NONE | | QUIET |********|********|********|********| NONE | | VERY QUIET |********|********|********|********| NONE | |-------------------|--------|--------|--------|--------|------------| | Geomagnetic Field | Sun. | Mon. | Tue. | Wed. | Anomaly | | Conditions | Given in 3-hourly UT intervals | Intensity | |____________________________________________________________________| NOTES: The data above represents preliminary planetary geomagnetic activity. Data from many magnetic observatories around the world are used in constructing the above chart. The first graph line for each day represents geomagnetic activity which occurred between 00 UT and 03 UT. The second graph line represents activity which occurred between 03 UT and 06 UT, etc. For information regarding the interpretation and/or use of these charts, send a request for the document "Understanding Solar Terrestrial Reports" to: oler@hg.uleth.ca. PLANETARY 10-DAY GEOMAGNETIC ACTIVITY OUTLOOK (25 APRIL - 04 MAY) ________________________________________________________________________ | EXTREMELY SEVERE | | | | | | | | | | | HIGH | | VERY SEVERE STORM | | | | | | | | | | | HIGH | | SEVERE STORM | | | | | | | | | | | MODERATE | | MAJOR STORM | | | | | | | | | | | LOW - MOD. | | MINOR STORM | | | | | | | | | | | LOW | | VERY ACTIVE | | | |* | | | | | | | NONE | | ACTIVE |** | * | **|***|** | * | * | * | | | NONE | | UNSETTLED |***|***|***|***|***|***|***|***|***|** | NONE | | QUIET |***|***|***|***|***|***|***|***|***|***| NONE | | VERY QUIET |***|***|***|***|***|***|***|***|***|***| NONE | |-------------------|---|---|---|---|---|---|---|---|---|---|------------| | Geomagnetic Field |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| Anomaly | | Conditions | Given in 8-hour intervals | Intensity | |________________________________________________________________________| CONFIDENCE LEVEL: 70% NOTES: Predicted geomagnetic activity is based heavily on recurrent phenomena. Transient energetic solar events cannot be predicted reliably over periods in excess of several days. Hence, there may be some deviations from the predictions due to the unpredictable transient solar component. GRAPHICAL ANALYSIS OF SOLAR ACTIVITY OVER THE PAST 60 DAYS Cumulative Graphical Analysis of Solar Activity ____________________________________________________________ 307|*F | HIGH 294|*F F = Major Flare(s) | HIGH 281|*F | HIGH 268|*F* F * * | HIGH 255|*F* F FF F * * *F* | HIGH 242|*F** F*FFFFFFF * ***F** | Moderate 229|*F*** F FFF*FFFFFFFF*FF F***F**** | Moderate 216|*F**** F ***FFF*FFFFFFFF*FF *F***F****F | Moderate 203|*F******FF*FF***FFF*FFFFFFFF*FF* **F***F****F | Moderate 190|*F******FF*FF***FFF*FFFFFFFF*FF**F*F*F***** **F***F****F | Moderate 177|*F******FF*FF***FFF*FFFFFFFF*FF**F*F*F********F***F****F* | Low 164|*F******FF*FF***FFF*FFFFFFFF*FF**F*F*F********F***F****F** | Low 151|*F******FF*FF***FFF*FFFFFFFF*FF**F*F*F********F***F****F** | Low 138|*F******FF*FF***FFF*FFFFFFFF*FF**F*F*F********F***F****F*** | Low 125|*F******FF*FF***FFF*FFFFFFFF*FF**F*F*F********F***F****F****| Very Low ------------------------------------------------------------ Cumulative 60 day Solar Activity Record Start Date: February 24, 1991 NOTES: Left-hand column digits represent the 10.7 cm solar radio flux obtained from Ottawa. The right-hand column describes the relative solar activity for that period based on the average number of major and minor flares that can be expected for related solar flux values. Plot lines labeled with the letter "F" represent days where at least one major flare occurred (ie. class M5 or greater flare). GRAPHICAL 20-DAY SOLAR ACTIVITY PREDICTION Solar Activity _________________________________________________________________ | 248 | | | | | | | | | | | | | | | | |**|**| | | | 240 | | | | | | | | | | | | | | |**|**| | |**|**| | 232 | | | | | | | | | | | | |**|**| | | | | | | | 223 | | | | | | | | | | | |**| | | | | | | | | | 215 | | | | | | | | | | |**| | | | | | | | | | | 206 | | | | | | | | | | | | | | | | | | | | | | 198 | | | | | | | | | |**| | | | | | | | | | | | 189 | | | | | | | | | | | | | | | | | | | | | | 181 | | | | | | | | |**| | | | | | | | | | | | | 172 | | | | | | |**|**| | | | | | | | | | | | | | 164 | | | | |**|**| | | | | | | | | | | | | | | | 155 | | | |**| | | | | | | | | | | | | | | | | | 147 | | | | | | | | | | | | | | | | | | | | | | 138 | |**|**| | | | | | | | | | | | | | | | | | | 130 |**| | | | | | | | | | | | | | | | | | | | |-----|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--| |Solar|25|26|27|28|29|30|01|02|03|04|05|06|07|08|09|10|11|12|13|14| |Flux | April | May | ----------------------------------------------------------------- CONFIDENCE LEVEL: 60% HF RADIO SIGNAL PROPAGATION PREDICTIONS (25 APRIL - 04 MAY) High Latitude Paths ________________________________________________________ | EXTREMELY GOOD | | | | | | | | | | | | VERY GOOD | | | | | | | | | | | CONFIDENCE | GOOD | | | | | | | | | | | LEVEL | FAIR | *|* *|* *| *| *|* *|* *|* *|***|***| ------- | POOR |** | * | * |** |** | * | * | * | | | 70% | VERY POOR | | | | | | | | | | | | EXTREMELY POOR | | | | | | | | | | | |----------------|---|---|---|---|---|---|---|---|---|---| | PROPAGATION |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| | QUALITY | Given in 8-Hour UT Intervals | -------------------------------------------------------- Middle Latitude Paths ________________________________________________________ | EXTREMELY GOOD | | | | | | | | | | | | VERY GOOD | | | | | | | | | | | CONFIDENCE | GOOD |***|***|* *| *| *|* *|* *|* *|***|***| LEVEL | FAIR | | | * |** |** | * | * | * | | | ------- | POOR | | | | | | | | | | | 70% | VERY POOR | | | | | | | | | | | | EXTREMELY POOR | | | | | | | | | | | |----------------|---|---|---|---|---|---|---|---|---|---| | PROPAGATION |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| | QUALITY | Given in 8-Hour UT Intervals | -------------------------------------------------------- Low Latitude Paths ________________________________________________________ | EXTREMELY GOOD | | | | | | | | | | | | VERY GOOD | *| | | | | | | | *| *| CONFIDENCE | GOOD |** |***|* *|* *|* *|***|***|***|** |** | LEVEL | FAIR | | | * | * | * | | | | | | ------- | POOR | | | | | | | | | | | 70% | VERY POOR | | | | | | | | | | | | EXTREMELY POOR | | | | | | | | | | | |----------------|---|---|---|---|---|---|---|---|---|---| | PROPAGATION |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| | QUALITY | Given in 8-Hour UT Intervals | -------------------------------------------------------- NOTES: NORTHERN HEMISPHERE SOUTHERN HEMISPHERE High latitudes >= 55 deg. N. | High latitudes >= 55 deg. S. Middle latitudes >= 40 < 55 deg. N. | Middle latitudes >= 35 < 55 deg. S. Low latitudes < 40 deg. N. | Low latitudes < 35 deg. S. POTENTIAL VHF DX PROPAGATION PREDICTIONS (25 APRIL - 04 MAY) INCLUDES SID AND AURORAL BACKSCATTER ENHANCEMENT PREDICTIONS HIGH LATITUDES __________________________________________________ ___________________ | SIGNAL | Given in 8 hour local time intervals | | SID ENHANCEMENT | | QUALITY |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| |T|F|S|S|M|T|W|T|F|S| |__________|___|___|___|___|___|___|___|___|___|___| |-|-|-|-|-|-|-|-|-|-| | VERY GOOD| | | | | | | | | | | 0%|*|*|*|*|*|*|*|*|*|*| |ABOVE NORM| | | | | | | | | | | 20%| | | | |*|*|*|*|*|*| | NORMAL|***|***|** | * |** |***|***|***|***|***| 40%| | | | | | | | | |*| |BELOW NORM| | | *|* *| *| | | | | | 60%| | | | | | | | | | | | VERY POOR| | | | | | | | | | | 80%| | | | | | | | | | | | BLACKOUT| | | | | | | | | | |100%| | | | | | | | | | | |==========|===|===|===|===|===|===|===|===|===|===| |-------------------| | 100% | | | | | | | | | | |100%| | | | | | | | | | | | 80% | | | | | | | | | | | 80%| | | | | | | | | | | | 60% | | | | | | | | | | | 60%| | | | | | | | | | | | 40% | | | *|* *|* *|* *| | | | | 40%| | |*|*|*|*| | | | | | 20% |* *|* *|* *|* *|***|***|***|***|***|***| 20%|*|*|*|*|*|*|*|*|*|*| | 0% |***|***|***|***|***|***|***|***|***|***| 0%|*|*|*|*|*|*|*|*|*|*| |----------+---|---|---|---|---|---|---|---|---|---| |-|-|-|-|-|-|-|-|-|-| |CHANCE OF |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| |T|F|S|S|M|T|W|T|F|S| | VHF DX | Given in 8 hour local time intervals | |AURORAL BACKSCATTER| |__________|_______________________________________| |___________________| MIDDLE LATITUDES __________________________________________________ ___________________ | SIGNAL | Given in 8 hour local time intervals | | SID ENHANCEMENT | | QUALITY |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| |T|F|S|S|M|T|W|T|F|S| |__________|___|___|___|___|___|___|___|___|___|___| |-|-|-|-|-|-|-|-|-|-| | VERY GOOD| | | | | | | | | | | 0%|*|*|*|*|*|*|*|*|*|*| |ABOVE NORM| | | | | | | | | | | 20%| | | | |*|*|*|*|*|*| | NORMAL|***|***|** | * | **|***|***|***|***|***| 40%| | | | | | | | | |*| |BELOW NORM| | | *|* *|* | | | | | | 60%| | | | | | | | | | | | VERY POOR| | | | | | | | | | | 80%| | | | | | | | | | | | BLACKOUT| | | | | | | | | | |100%| | | | | | | | | | | |==========|===|===|===|===|===|===|===|===|===|===| |-------------------| | 100% | | | | | | | | | | |100%| | | | | | | | | | | | 80% | | | | | | | | | | | 80%| | | | | | | | | | | | 60% | | | | | | | | | | | 60%| | | | | | | | | | | | 40% | | | | | | | | | | | 40%| | | | | | | | | | | | 20% | | |* *|* *|***|***| * | * | **| **| 20%| | |*|*|*|*| | | | | | 0% |***|***|***|***|***|***|***|***|***|***| 0%|*|*|*|*|*|*|*|*|*|*| |----------+---|---|---|---|---|---|---|---|---|---| |-|-|-|-|-|-|-|-|-|-| |CHANCE OF |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| |T|F|S|S|M|T|W|T|F|S| | VHF DX | Given in 8 hour local time intervals | |AURORAL BACKSCATTER| |__________|_______________________________________| |___________________| LOW LATITUDES __________________________________________________ ___________________ | SIGNAL | Given in 8 hour local time intervals | | SID ENHANCEMENT | | QUALITY |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| |T|F|S|S|M|T|W|T|F|S| |__________|___|___|___|___|___|___|___|___|___|___| |-|-|-|-|-|-|-|-|-|-| | VERY GOOD| | | | | | | | | | | 0%|*|*|*|*|*|*|*|*|*|*| |ABOVE NORM| | | | | | | | | | | 20%| | | | |*|*|*|*|*|*| | NORMAL|***|***|***|***|***|***|***|***|***|***| 40%| | | | | | | | | |*| |BELOW NORM| | | | | | | | | | | 60%| | | | | | | | | | | | VERY POOR| | | | | | | | | | | 80%| | | | | | | | | | | | BLACKOUT| | | | | | | | | | |100%| | | | | | | | | | | |==========|===|===|===|===|===|===|===|===|===|===| |-------------------| | 100% | | | | | | | | | | |100%| | | | | | | | | | | | 80% | | | | | | | | | | | 80%| | | | | | | | | | | | 60% | | | | | | | | | | | 60%| | | | | | | | | | | | 40% | | | | | | | | | | | 40%| | | | | | | | | | | | 20% | | | | | * | * | * | * | **| **| 20%| | | | | | | | | | | | 0% |***|***|***|***|***|***|***|***|***|***| 0%|*|*|*|*|*|*|*|*|*|*| |----------+---|---|---|---|---|---|---|---|---|---| |-|-|-|-|-|-|-|-|-|-| |CHANCE OF |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| |T|F|S|S|M|T|W|T|F|S| | VHF DX | Given in 8 hour local time intervals | |AURORAL BACKSCATTER| |__________|_______________________________________| |___________________| NOTES: These VHF DX prediction charts are defined for the 50 MHz to 220 MHz bands. They are based primarily on phenomena which can affect VHF DX propagation globally. They should be used only as a guide to potential DX conditions on VHF bands. Latitudinal boundaries are the same as those for the HF predictions charts. For more information, request the document "Understanding Solar Terrestrial Reports" from: "oler@hg.uleth.ca". AURORAL ACTIVITY PREDICTIONS (25 APRIL - 04 MAY) High Latitude Locations ________________________________________________________ | EXTREMELY HIGH | | | | | | | | | | | CONFIDENCE | VERY HIGH | | | | | | | | | | | LEVEL | HIGH | | | | | | | | | | | ------- | MODERATE | * | | * |***| * | * | * | * | | | 60% | LOW |***|***|***|***|***|***|***|***|***|***| | NOT VISIBLE |***|***|***|***|***|***|***|***|***|***| |----------------|---|---|---|---|---|---|---|---|---|---| | AURORAL |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| | INTENSITY | Eve.Twilight/Midnight/Morn.Twilight | -------------------------------------------------------- Middle Latitude Locations ________________________________________________________ | EXTREMELY HIGH | | | | | | | | | | | CONFIDENCE | VERY HIGH | | | | | | | | | | | LEVEL | HIGH | | | | | | | | | | | ------- | MODERATE | | | | | | | | | | | 75% | LOW | * | | * | * | * | | | | | | | NOT VISIBLE |***|***|***|***|***|***|***|***|***|***| |----------------|---|---|---|---|---|---|---|---|---|---| | AURORAL |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| | INTENSITY | Eve.Twilight/Midnight/Morn.Twilight | -------------------------------------------------------- Low Latitude Locations ________________________________________________________ | EXTREMELY HIGH | | | | | | | | | | | CONFIDENCE | VERY HIGH | | | | | | | | | | | LEVEL | HIGH | | | | | | | | | | | ------- | MODERATE | | | | | | | | | | | 95% | LOW | | | | | | | | | | | | NOT VISIBLE |***|***|***|***|***|***|***|***|***|***| |----------------|---|---|---|---|---|---|---|---|---|---| | AURORAL |Thu|Fri|Sat|Sun|Mon|Tue|Wed|Thu|Fri|Sat| | INTENSITY | Eve.Twilight/Midnight/Morn.Twilight | -------------------------------------------------------- NOTE: For more information regarding these charts, send a request for the document, "Understanding Solar Terrestrial Reports" to: oler@hg.uleth.ca. ** End of Report ** ------------------------------ End of SPACE Digest V13 #462 *******************