Differences

This shows you the differences between two versions of the page.

Link to this comparison view

hardware:radio:hf [2018/07/29 17:58] (current)
Line 1: Line 1:
 +====== HF Radio Summary ======
 +
 +===== HF Radio Power Calcs =====
 +
 +EBR = Effective Bit Rate (Bytes/Second)\\
 +SS = Sample Size (Bytes/Sample)\\
 +PT = Preamble Time (Seconds)\\
 +SR = Sample Rate (Samples/Second)\\
 +GD = Group Duration (Seconds, how long are you grouping)\\
 +GS = Group Size (Samples/Group) = <m>SR * GD</m>\\
 +<m>SP_{n}</m> = Sample Power for Flight Interval n (seconds)\\
 +<m>TS_{n}</m> = Number of Transmissions per Second in Flight Interval n\\
 +TP = Power Used by Transmitter during TX (mW)\\
 +PB = Total Power Budget Required (mW-S)
 +
 +<m>SP_{n} = (SS/EBR) * (GS) + (PT)</m>
 +
 +<m>TS_{n} = {{Interval Duration}*{SR}}/{Group Size}</m>
 +
 +<m>PB = TP * sum{n}{}{SP_{n} * TS_{n}}</m>
 +
 +==== Example 1 ====
 +
 +Two Flight Intervals: Over the US, Not Over the US.\\
 +Total Flight Time = 72 Hours\\
 +
 +For Flight Interval 1, Over the US:\\
 +
 +Over the US is represented by a single large group.  Group Size = <m>{Samples/Minute} * {Minutes Over the US}</m>
 +
 +For this example, we will spend 330 Minutes over the US, 1 Sample / Minute * 5.5 hours = 330
 +
 +EBR = 12 Bytes / Second\\
 +SS = 50 Bytes\\
 +PT = 30 Seconds\\
 +GS = 330 Samples\\
 +
 +<m>SP_{1} = (50/12) * (330) + (30) = 1405 Seconds</m>
 +
 +<m>TS_{1} = {{330 minutes}*{{1 Sample}/{Minute}}}/{330} = 1</m>
 +
 +For Flight Interval 2, Not Over the US:\\
 +
 +For this example, we will group for 15 minutes at a time. For this example, we spend 3990 minutes NOT over the US. 
 +
 +EBR = 12 Bytes/ Second\\
 +SS = 50 Bytes\\
 +PT = 30 Seconds\\
 +GS = (1 Sample/Minute) * (15 minutes) = 15 Samples\\
 +
 +<m>SP_{2} = (50/12) * (15) + (30) = 92.5 Seconds</m>
 +
 +<m>TS_{2} = {{3990 minutes}*{{1 Sample}/{Minute}}}/{15} = 266</m>
 +
 +Putting it all together:
 +
 +TP = 2000mW
 +
 +<m>PB = 2000mW * {{1405 Seconds}*{1} + {92.5 Seconds}*{266}} = 52020000 mW-S = 14450 mW-H</m>
 +
 +Assuming each battery cell delivers 1 volt at high current draw, and 1500 mA-H: 1500 mW-H / Cell = 10 Cells
  
hardware/radio/hf.txt · Last modified: 2018/07/29 17:58 (external edit)
 
Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 3.0 Unported
Recent changes RSS feed Donate Powered by PHP Valid XHTML 1.0 Valid CSS Driven by DokuWiki