How to read DAF (double precision array file) "transfer" files? - encoding

Question

I downloaded some data in DAF "transfer" format, which NASA completely
fails to explain here:
http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/daf.html#Conversion%20and%20Transfer%20of%20DAF%27s
How do I read this file. Here are the first few lines I'm trying to comprehend:
DAFETF NAIF DAF ENCODED TRANSFER FILE
'DAF/SPK '
'2'
'6'
'NIO2SPK '
BEGIN_ARRAY 1 3895604
'URA111 '
'-BC186A96D0E76^8'
'BC0DDF032F041^8'
'2BD'
'7'
'1'
'3'
1024
'-BC18166^8'
'FD2^4'
'-DA4A19AC2BCD18^4'
'-4D5E7E1A67739^4'
'1D46248537C30E^5'
'EBA587DFA5E3B^3'
'-26885CE73CB0D^4'
'-BF0DC6EDB5B2C8^2'
'129C1CFEABE48^3'
'5594FC676368^1'
'-472EBF2225A^1'
'-2198AE1963D^0'
'79CC4CA0C^-1'
'FDD9792D82^-2'
'2001D81A^-2'
'333BCEE2BDD724^4'
'-D78AA10831D9C8^4'
'-6D712677574DF8^4'
'283A14783CDC^4'
'90AC22194ABF6^3'
'-1DEF6219F664FE^3'
'-47318F604096^2'
'9B805F405B1C^1'
'1275B947E2AC^1'
'-16A664664D^0'
'-2F614B9F5^-1'
'-B7C3E41D^-3'
'2F3D71F8^-3'
According to NASA, this is/was a popular format for Fortran programs,
but google was not at all helpful (wikipedia doesn't have an entry
either).

Answer 1

OK, I think I finally figured it out at least part of this. For
reference, the original file (a whopping 162M in size) is the
ura111.bsp file in:
http://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/
and converted to ura111.xsp using the toxfr program in:
http://naif.jpl.nasa.gov/pub/naif/utilities/SunIntel_32bit/
The small files:
http://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/ura111.cmt
http://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/satellites/ura111.inp
explain more about the main file.
Things like "-BC18166^8" really are double precision numbers, written
in modified hexadecimal IEEE-754 format. Wikipedia sort of explains
this format here:
http://en.wikipedia.org/wiki/IEEE-754
and there are IEEE-754-to-decimal convertors like this:
http://www.h-schmidt.net/FloatConverter/ (and many others)
However, these don't explain/convert the exact format NASA uses, which
was one reason for my confusion.
For reference "-BC18166^8" is converted as follows:
The decimal value of "BC18166" is 197230950
We now divide by 16 repeatedly until the result is less than 1 (in
other words, we divide by 16^(length of "BC18166")), yielding
0.734742544591427
The '^8' means we multiply by 16**8 to get 3155695200
the leading "-" just means we add a minus sign to get -3155695200
Of course, we could've combined steps 2 and 3 and just multiplied
197230950 by 16.
#klugerama, to answer your question, yes, I am trying to write a file
parser, this time in Perl, as part of a program that accurately
identifies the positions of various objects in our solar system.
I've already parsed the NASA files relating to planets (and Earth's
own moon) here:
ftp://ssd.jpl.nasa.gov/pub/eph/planets/ascii/
but these are in a much different and far easier-to-parse format.

Answer 2

This document (hosted at ucla.edu) has a complete description of the file format.
Addtionally, check out this python project on Github. It appears to provide the DAFTB function you're looking for.
Edit For the record (cough), it doesn't look like this format was ever intended to be read, per se, by humans. It's a transfer format intended to be converted back to usable binary in whatever executable code is appropriate.
You didn't explain why you want to do this. So unless you are writing a file parser (which has been done already in at least two languages), I'm not sure what the benefit is of being able to read the raw values.
Strictly speaking, the answer to your question is that you use software (see link above) to read it.