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.Effectivecommunications systems require accurate and timely communicationselectronics engineering analysis support for operational and combat units.Tomeet this demand, the Joint Chiefs of Staff has established the Joint SpectrumCenter (JSC).Based in Annapolis, Maryland, JSC has served to ensure theDOD s effective use of the electromagnetic spectrum in support of nationalsecurity and military objectives since 1960.JSC provides operational supportby assisting Marine Corps units in identifying the anticipated physical andelectronic environment and then providing analysis support assessing theeffect of the environment on the unit's ability to accomplish its mission.ScopeThis appendix describes the various analytical capabilities and the input datarequired for Marine Corps communications electronics engineering andelectro-magnetic compatibility support through JSC.Note: Appendix B is professional reference material designed to enhanceyour abilities only; this information is not tested in this course.In ThisThis appendix contains the following topics:AppendixTopic See PageOverview B-1Point-to-Point Multichannel Predictions B-2Received Signal Level (RSL) Coverage Overlays B-4Line-of-Sight (LOS) Coverage Overlays B-7High Frequency (HF) Sky Wave Propagation Predictions B-10High Frequency (HF) Ground Wave Propagation Predictions B-11Three-Dimensional Terrain Plots B-12Terrain Horizon Plots B-13How to Contact the JSC B-14MCI Course 2515H B-1 Appendix BPoint-to-Point Multichannel PredictionsDescriptionThe point-to-point multichannel circuit reliability analyses predict short-termreliabilities for wideband multichannel circuits.Reliability is predicted bydetermining the terrain-dependent path loss, received signal level, andestimated fade margin.Data provided in the prediction includes antennahorizon angle, true and magnetic azimuths, path distance, reliabilitypercentages, and propagation modes.Terrain ProfileFor point-to-point reliability analyses, a profile of the terrain between twopoints can also be beneficial.The diagram below shows such a terrainprofile.Continued on next pageMCI Course 2515H B-2 Appendix BPoint-to-Point Multichannel Predictions, ContinuedRequiredThe following information is required for point-to-point multichannelInformationreliability predictions:" Transmitter and receiver site locations, latitude/longitude, DDMMSS" Equipment nomenclature and model number" Antenna gain (dBi), if known" Type of antennas, transmitter and receiver" Required delivery date" Organization and mailing address" Phone numbers (voice and fax)" Point of contactMCI Course 2515H B-3 Appendix BReceived Signal Level (RSL) Coverage OverlaysDescriptionRadio RSL coverage overlays are used to depict the approximate signal levelsaround a transmitter site taking into account such circuit parameters astransmitter power, transmit and receive antenna gains, and terrain topographicelevations data.This type of analysis is used to predict the area of reliablecommunications for tactical equipment and to determine the susceptibility offriendly equipment to enemy intercept/jamming.The RSL coverage overlaysare normally provided at a map scale of 1:250,000, but may be varied to meetthe user s needs.The coverage predictions can represent one transmitter,multiple transmitters, or the combined/composite coverage of severaltransmitters.The overlays can represent ground-to-ground, air-to-ground,and ground-to-air coverage.Single SiteThe diagram below is an example of a received signal level coverage overlayCoveragefor a single site.The tic marks on the contour lines point to the area of lesserOverlaysignal strength.Continued on next pageMCI Course 2515H B-4 Appendix BReceived Signal Level (RSL) Coverage Overlays, ContinuedMultiple SiteThe diagram below is an example of a received signal level coverage overlayCoveragefor multiple sites.The tic marks on the contour lines point to the area ofOverlaylesser signal strength.Continued on next pageMCI Course 2515H B-5 Appendix BReceived Signal Level (RSL) Coverage Overlays, ContinuedRequiredThe following information is required for RSL coverage overlays:Information" Transmitter site location, latitude/longitude, DDMMSS" Transmitter output power" Transmitter and receiver antenna type" Antennas gain, if known" Antenna height above ground" Equipment type and model number" Organization and mailing address" Phone numbers (voice and fax)" Point of contactMCI Course 2515H B-6 Appendix BLine-of-Sight (LOS) Coverage OverlaysDescriptionLight-of-sight (LOS) coverage overlays depict LOS around radio and radarsites.This analysis is especially useful for choosing relay/retransmission sitesfor tactical radios and microwave terminal locations, and for positioning otherLOS communication equipment.Additionally, radar LOS coverage overlaysenable easy assessment of site suitability with respect to the detection ofincoming targets.LOS OverlayThe diagram below is an example of a radio LOS coverage overlay for atactical transmitter.The tic marks on the contour lines point to the areas thatare within the transmitter s line-of-sight.Continued on next pageMCI Course 2515H B-7 Appendix BLine-of-Sight (LOS) Coverage Overlays, ContinuedRadar OverlayThe diagram below is an example of a LOS coverage overlay for radarequipment.The coverage contours shown depict the radar target acquisitiondistance for targets at various altitudes.Target altitudes may be specifiedabove mean sea level (MSL) or above ground level (AGL).In this example,target altitudes of 250 to 8,000 feet above MSL are specified.Continued on next pageMCI Course 2515H B-8 Appendix BLine-of-Sight (LOS) Coverage Overlays, ContinuedRequiredThe following information is required for LOS coverage overlays:Information" Transmitter site location, latitude/longitude, DDMMSS" Transmitter antenna height above ground" Coverage radius" Target altitudes (radar LOS only)" Receiver antenna height above ground (radio LOS only)" Required delivery date" Organization and mailing address" Phone numbers (voice and fax)" Point of contactMCI Course 2515H B-9 Appendix BHigh Frequency (HF) Sky Wave Propagation PredictionsDescriptionHigh frequency (HF) sky wave propagation predictions describe the usablefrequencies and the predicted circuit reliability between a transmitter andreceiver site.The most common formats available for JSC HF predictions are" Method 28" Method 31" Method 34Method 28Method 28 provides predictions for maximum usable frequency (MUF),frequency of optimum transmission (FOT), and lowest usable frequency(LUF) for HF sky wave path between a transmitter and receiver site for a 24-hour period for a specific month [ Pobierz całość w formacie PDF ]