NAME

visible - sees if celestial object is within telescope limits

SYNOPSIS

visible [delay=] [iso=] [verbose] [buffer=] [encoder | ttl | [pasthru]] [debug..] [window[=] [nodut] [decimal] [high] [nocheck] [over]
visible [iso=] [quiet] [buffer=] [encoder | ttl | [pasthru]] [cw] [nowrap] [debug..] [decimal] [high] [nocheck] .. for altaz telescopes

DESCRIPTION

This program reads Coordinate Strings arriving in stdin containing the ra, dec, (equinox) or HA/Dec or Alt/Az and optional label of the celestial coordinates similar to: 
ra=07:09:17.6 dec=23:13:31 equinox=2000.0 mag=14.0 name=Edith
The default mode is ICRS. If the coordinate is within the limits of the telescope the coordinates and label will be copied to stdout. If the coordinate is outside of the limit, the first offending limit will be echoed to stdout when the verbose option is used. Limits are: east, west, north, south and altitude (azimuth for altaz telescopes).

The current time is used unless overridden by the iso=,jd= or delay= options. The latitude and longitude and limits and type of telescope are derived from the the telescope server rtel tel_status command.

For altazimuth telescope special options are allowed to take care of cable wrap.

For coelostats East and West are unlimited, North and South are assumed to be +/- 30 degrees respectively. Altitude is used if present, otherwise is zero.

OPTIONS

delay= delays the window by the specified number of seconds from the current time.

nodut - disables Delta UT calculations.

iso=YYYY-MM-DDTHH:MM:SSZ - sets the universal time and date as specified by the ISO notation.

buffer= avoids limits by the the specified angle in degrees.

nocheck - doesn't check limits (use with encoder).

over - in pass thru mode, allows over the pole stars and adds string "over=". In encoder mode forces over the pole encoder.

decimal - decimal degree output.

high - more (in)significant figures.

window[=alt] - prints out the rise and setting times of the objects in stdin. If used without limits, the telescope limits are used (Equatorial mode only). If an equal sign is present it is to be followed by a setting altitude in degrees and telescope limits will be ignored.

verbose - writes limit messages.

DISPLAY OPTIONS

encoder - displays the hour angle, declination, azimuth and actual azimuth (for altaz systems). The hour angle is the mechanical versions, in other words declination can go above 90 when flipped over the pole. The output is in decimal degrees.

ttl - displays time to limit in seconds, time before limit, and what limit is struck. Wrapping is disabled in this mode for altaz telescopes. 

Code/pointing> echo ra=10 dec=50 | visible ttl
ttl=21240 seconds west limit ha=86.0

passthru - just passes the coordinates through to the output. this is the default.

window - modes printout the rise and set times in ISO format and the time above the horizon in decimal hours.

ALTAZIMUTH OPTIONS

cw - starts the telescope 180 degrees from the clockwise (+) limit in azimuth. The default is 180 degrees from the counterclockwise (-) limit.

nowrap - does not allow the telescope to slew by more than 180 degrees in azimuth to avoid cable wrap. The default does.

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