Subject: Re: How do you measure whales?

Dagmar_Fertl@smtp.mms.gov
Thu, 03 Oct 96 09:31:20 EST

     Dear Zach,
     
     I assume your question is about how one would measure a blue whale out 
     at sea, and not one that washed up on a beach.  There are various 
     techniques that use photogrammetry (the science of making precise 
     measurements using photography).  This is a technique borrowed from 
     surveying and map making.  It allows obtaining exact body measurements 
     of animals from photographs.  One method requires photographs to be 
     taken from a known distance with a camera of known focal length.  
     Another method requires reference objects of known size at the same 
     distance from the camera as the subject (for example, mounting a 
     one-meter disc on a boat and taking aerial photographs, as was done 
     for right whales).  Another way to do the pictures is by aerial stereo 
     imagery.  
     
     Accurate length measurements are required for age and weight 
     calculations and were previously only obtainable from dead animals.
     
     Another use of photogrammetry has been used to measure relative growth 
     rates of calves compared to their mothers.  This method requires a 
     sequence of photographs of mother and calf together throughout the 
     growth of the calf.  
     
     Filming may be done with still photography or video.   
     
     Good luck on the project!!


______________________________ Reply Separator _________________________________
Subject: How do you measure whales?
Author:  Zach Price <zkarde@architech.com> at ~smtp
Date:    10/2/96 7:55 PM


I'm working on a Science project and the project is to create your own 
way of measuring a blue whale. I've already done that part, but I'm 
curious to find out how real scientists do it, too. I can't find any 
information on it online, so I'm asking you. 
 -Zach Price