How Do We Find Lunar Orbiter Images?

Dennis Wingo: Several people were interested in our process yesterday so here is some more information on what we do to figure out the images on the tapes. [Click on image to enlarge].
We almost always start with the low numbered tapes and go up, just like in the real mission. As stated yesterday, we picked Woomera because it had the most ground station time. There is 163 tapes for the Woomera LO-V, more than 50-60 tapes than for the previous LO’s. We think that there is some duplication there but we won’t know until we get all of the Woomera tapes done, then process the raw framelets. Austin then generates a report based upon our knowledge of all of the framelets for LO-V, which then tells us what we have left to do. We then will start on the Goldstone tapes.

Just like figuring out a dead language, there is a lot you have to figure out from the documentation (Which is actually quite good for Lunar Orbiter) what is what. It took us forever to figure out for example that the Sequence Numbers on the tape cans actually represent orbit numbers. What is never stated in any documentation is that these sequence numbers only begin AFTER the first images are processed on board and then read out. Thus the first read out should be sequence 001. However, from what we have actually seen the sequence number starts at 004. No information about why.
The document image of the day today is the first page from the “Photographic Operational Data Summary”. It has the sequence numbers (which start with 002 which may be on a Madrid or Goldstone tape though the first ground station from the documents should have been Woomera), and it has the image numbers, and framelets for each image and the framelets captured per sequence. For us there is usually two or three or four tapes per sequence. You can get an idea about how many tapes by looking at the number of framelets per sequence at the lower left of the page. We get the idea that there may be some duplication because there are frame lets with low sequence numbers (R/O SEQ on the left), and sequence numbers with similar framelets that are much higher sequence numbers (142-148). We won’t know until we play those tapes, but it is a pretty good bet.
Here is the first page, now you figure it out! (Note you have the benefit of our years of working this in the explanation above so don’t think you are that smart!)