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Subject: Re: Celestial Calculator Comparisons
From: Richard B. Emerson (navsys@XXX.XXX)
Date: Thu Mar 09 2000 - 10:17:56 EST
Harjit Singh writes:
> Can anyone, give me some information on the PC Sightmaster, as compared to
> the other calculators?
>
While I haven't used PC Sightmaster, I'll offer a couple of comments
about "other calculators", specifically the Celesticomp V and
StarPilot. I own both although I just bought the StarPilot about two
weeks ago.
The main advantage over these calculators is they don't live on a PC
(although StarPilot, through its host TI-86 can make some use of a PC
for updates and printing output). Celesticomp uses a programable
Sharp calculator with long-life lithium batteries (I haven't had to
change mine in over two years) while StarPilot uses a TI-86 which uses
AAA alkaline batteries (projected life is about a year) and a lithium
backup battery.
The basic sight reduction process is common to all three products; the
difference is the user interface and added features (e.g., sight
planning, set and drift calculations). StarPilot is loaded with
options and uses a larger screen to display prompts. Celesticomp fits
all prompts into one line and can, on occasion, be a little cryptic
(but a little practice smooths over this wrinkle). It doesn't have as
many "chrome" features (for example, StarPilot can do lunars and uses
its screen to give a rough map of stars). On balance, the added
"chrome" can actually impede usefulness (for example, if data is input
on one for air temperature and pressure and then forgotten in another
day's work, it could be a problem).
Documantation for both products is, I think, a triffle thin. While
each product has examples demonstrating the calculators' functions, I
came away with the feeling that I wasn't quite ready to go to sea
based solely on what I'd learned from the manuals. Now, in all
fairness, there is the very real issue, for the writers, of drawing
the line between "this is how to use this product" and "how to
navigate, coincidentally using this product". One demonstration of
what I'm referring to is the short dip option. StarPilot can use
Short Dip (where the horizon used for a sight is closer than the
visual horizon - this is useful when practicing sights on a small bay
or lake, for example) and this option is described to some extent
(page 19 or section 10.11, for those reading along [g]) but, aside
from knowing the option exists, I still don't know where the actual
distance to the horizon is entered. Also, there are a few typos
(e.g., "Resale" for "Rescale") which seem to plague Starpath products
in general. Nevertheless, I think StarPilot, bcause of its connection
with Starpath and their navigation training courses, gets a slight nod
for its manual.
On the question which is easier to learn, I think it's a draw.
Celesticomp's inputs are a little easier to get to and check (for
example, date, fix time, DR data can be inspected at the start of each
sight reduction or skipped over with one key stroke). The prompts are
short and based learned by using the calculator in some practice runs.
StarPilot, once all the options are understood, can be set up a little
more easily because most prompts aren't as brief ("WT" for watch time
still bothers me but that's a personal quirk) as the Celesticomp's.
Remembering all of the options, however, is a slightly larger chore.
On the matter of price, the Celesticomp V (list price is about US$250)
is available from a limited number of sources but, with a little
effort, can be found at a discount. StarPilot lists for the same
price but is sold both with the calculator and on a CD-ROM or via
Internet download (along with the documentation which is supplied in
PDF format and can be read without a license). I bought a brand new
TI-86 on eBay for US$65 (discounted prices vary from about US$100 to
US$130). The GraphLink adapter (one time purchase to connect the
TI-86 to a PC) sells for US$20 or, in a couple of cases, US$19.95. I
ordered it and the software download license ($119) from StarPath.
When asked to recommend the Celesticomp or the StarPath to a friend, I
said that the Celesticomp is a little less complex and better for the
person who says "all I want is to just reduce sights and do my own
plotting". StarPilot is for the person who wants the option to use
more of the lesser known navigation techniques (e.g., meridian
transits, latitude from the altitude of Polaris, or GMT from lunar
distances). There is no clear-cut "A is better than B" in this
comparision; each product is very good and the decision will have to
be made on what fits individual needs. It's easier to fit either (or
both! [g]) in my nav bag than it is to fit in my laptop.
DISCLAIMER: As stated above, I own the products mentioned but have no
other connection with either Celesticomp or Starpath, save as a
customer.
Rick
S/V One With The Wind, Baba 35
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