subroutine obsbeg - j.f.chandler, 1977 oct
compar link page format control routine
each observables main program should call obsbeg at the very
beginning to set up data set flags, note the current page and
print a header line.  header looks like:
typetypetypetype observations of   body   made from sitename
series=....  (spot=....)  frequency= ................
a second line is also printed for ncodf.gt.20
this header also appears on every subsequent page of the series

after setup is done, the program should call obsbgt to get the
elapsed time printed out and the header read back from "intern"
and printed.
no arguments for obsbgt.

for every observation record (except a below-horizon dummy) the
main routine should call obscnt to form residuals, accumulate
error quantities, and check for full page.  ordinarily, no
printout appears except the usual one line per record, but
if any other routines also print on iout, then
whenever the line count exceeds 57, the responsible
program should call entry obspag.  this will print out any
deletions on the current page and start a new one.  the main
program must have called obsbgt already to set up the
observation data header.  it is also printed.

lab1 - name of first observable
l1 - length (in words) of lab1.  should be 2-4
lab2 - name of second observable
l2 - length of lab2.

at the end of a series the main program should call obsend.
this will print out any
deletions on the last page and then print out the usual trailer
detailing the type of observation, the pages used, the average
number of iterations needed, and a header for the error
analysis summary which appears at the end of the series.
no arguments for obscnt, obsend or obspag.