Its been a while since my last post. In that time I have been busy with life stuff.<\/p>\n\n\n\n
Here is a script I wrote to convert the current time in to sidereal time (GM sidereal time and also local sidereal time)
I have modified it in to functions so its a little more user friendly to non scripters.<\/p>\n\n\n\n
Its has 4 functions
1 convert the time and location data in to sidereal time
2 ask the user to enter a location or use the current location of there geolocated IP
3 ask the user to enter a date time or use the current date\/time
4 a nice function a human can run <\/p>\n\n\n\n
Running this script will load all the functions in to memory and run the very last command to call them.
I have put in some comments with different uses for this command. Just uncomment (remove the “#”) out the like you want to run.<\/p>\n\n\n
\n### start of functions ###\n\n# this function will get current location and time or ask for them, then convert the sidereal time (both local and Greenwhich Mean)\n# it is a wraper for the following 3 functions in this script\n# usage\n# Get-SiderealTime -- will get the current location and time and convert to sidereal time\n# Get-SiderealTime -AskLocation "no" -AskTime "no" -- will get the current location and time and convert to sidereal time\n# Get-SiderealTime -AskLocation "no" -AskTime "yes" -- will get the current location and prompt for time. then convert to sidereal time\n# Get-SiderealTime -AskLocation "yes" -AskTime "yes" -- will promt for the current location time. then convert to sidereal time\n# the function will write to the screen, it currenlty has no output\nfunction Get-SiderealTime\n{\n [CmdletBinding()]\n param( \n [Parameter(Mandatory = $false)] $AskLocation = "no",\n [Parameter(Mandatory = $false)] $AskTime = "no"\n )\n\n $LocationObject = Get-UserLocation -AskLocation $AskLocation\n $DateTimeObject = Get-UserTime -AskTime $AskTime\n\n Get-SiderealDateTime -LocationObj $LocationObject -DateTimeObj $DateTimeObject\n}\n\n\n# will use the current external IP address found by requesting it form ifconfig.me and send it to "http:\/\/ip-api.com\/json\/" to get giolocated\n# will not work if the user is using a VPN\n# usage\n# Get-UserLocation -asklocation "yes" -- will prompt for Latitude and Longitude\n# Get-UserLocation -asklocation "No" -- (default) will giolocate external IP\nfunction Get-UserLocation\n{\n [CmdletBinding()]\n param( \n [Parameter(Mandatory = $false)] $AskLocation = "no"\n )\n\n if ($AskLocation -eq "no")\n {\n $LocationData = Invoke-RestMethod -Method Get -Uri ("http:\/\/ip-api.com\/json\/" + (curl ifconfig.me).content )\n }else{\n $LocationData = '' | select lat,lon,status,city,regionName\n $LocationData.city = "NA"\n $LocationData.regionName = "NA"\n write-host "Enter Latitude in degrees (eg Latitude of Brighton is 50.8229)"\n [Decimal]$LocationData.lat = read-host "Latitude"\n write-host "Enter Longitude in degrees (eg Longitude of Brighton is -0.1363)"\n [Decimal]$LocationData.lon = read-host "Longitude" \n if ($LocationData.lat -and $LocationData.lon){$LocationData.status = "success"} \n }\n\n if ($LocationData.status -eq "success")\n {\n write-host (" " + $LocationData.city + " , " + $LocationData.regionName) -ForegroundColor Green\n write-host (" Long " + $LocationData.lon + " , Lat " + $LocationData.lat) -ForegroundColor Green\n write-host " =============================== " -ForegroundColor Green\n }\n return $LocationData\n}\n\n# will use get the current date and time unless instrusted to promp for a date and time\n# usage\n# Get-UserTime -AskTime "yes" -- will prompt for date time in the following format 17\/07\/2017 09:00:00\n# Get-UserTime -AskTime "No" -- (default) will get current date and time\n# Get-UserTime -AskTime "any" -DateTimeObj (get-date) -- will check and return the datetime object, or the current date time if its invalid\nfunction Get-UserTime\n{\n [CmdletBinding()]\n param( \n [Parameter(Mandatory = $false)] $AskTime = "no",\n [Parameter(Mandatory = $false)] $DateTimeObj\n )\n\n if($DateTimeObj)\n {\n if ($DateTimeObj.gettype() = "DataTime")\n {\n return $DateTimeObj\n }else{\n # not vailid, get getting current date time\n return get-date\n }\n }\n\n if ($AskTime -eq "no")\n {\n return get-date\n }else{\n write-host "Enter the date and time in the following format"\n $StartDate = Get-Date (Read-Host -Prompt 'Enter the date and time: 17\/07\/2017 or 17\/07\/2017 09:00:00')\n if ($StartDate.gettype().name -eq "datetime"){return $StartDate}\n }\n return get-date\n}\n\n# will take the location, datetime objects and output the Greenwhich and local sidereal time\n# formula from https:\/\/aa.usno.navy.mil\/faq\/GAST\n# some code ideas from https:\/\/github.com\/jhaupt\/Sidereal-Time-Calculator\/blob\/master\/SiderealTimeCalculator.py\nfunction Get-SiderealDateTime\n{\n [CmdletBinding()]\n param( \n [Parameter(Mandatory = $true)] $LocationObj,\n [Parameter(Mandatory = $true)] $DateTimeObj\n )\n\n $Datenow = $DateTimeObj\n if($Datenow.IsDaylightSavingTime()){$DateNow = $DateNow.addhours(-1)}\n\n $LocationData = $LocationObj\n\n # split TD into individual variables for month, day, etc. and convert to floatingPoint\n [float]$Month = $DateNow.month\n [float]$Day = $DateNow.day\n [float]$Year = $DateNow.year\n [float]$Hour = $DateNow.hour\n [float]$Min = $DateNow.Minute\n\n # convert mm to fractional time:\n [float]$Min = $Min\/60\n\n # reformat UTC time as fractional hours:\n [float]$UT = $Hour + $Min\n\n # get the Julian date:\n $JD = (367 * $Year) - [Math]::Truncate(( 7 * ($Year + [Math]::Truncate(($Month + 9) \/ 12) )) \/ 4) + [Math]::Truncate((275 * $Month) \/ 9) + $Day + 1721013.5 + ( $UT \/ 24)\n write-host ("Julian date " + $JD) -ForegroundColor Green\n write-host ("Date \/ time " + $DateNow) -ForegroundColor Green\n\n # get the Greenwhich mean sidereal time:\n $GMST = 18.697374558 + 24.06570982441908 * ($JD - 2451545)\n $GMST = $GMST % 24 #use modulo operator to convert to 24 hours\n $GMSTmm = ($GMST - [Math]::Truncate($GMST)) * 60 #convert fraction hours to minutes\n $GMSTss = ($GMSTmm - [Math]::Truncate($GMSTmm)) * 60 #convert fractional minutes to seconds\n $GMSThh = [Math]::Truncate($GMST)\n $GMSTmm = [Math]::Truncate($GMSTmm)\n $GMSTss = [Math]::Truncate($GMSTss)\n write-host ("Greenwhich Mean Sidereal Time: " + $GMSThh + ":" + $GMSTmm + ":" + $GMSTss) -ForegroundColor Green\n\n # Convert to the local sidereal time by adding the longitude (in hours) from the GMST.\n # (Hours = Degrees\/15, Degrees = Hours*15)\n $Long = $LocationData.lon \/ 15 #Convert longitude to hours\n $LST = $GMST + $Long #Fraction LST. If negative add 24\n if ($LST -lt 0)\n {$LST = $LST +24}\n $LSTmm = ($LST - [Math]::Truncate($LST)) * 60 #convert fraction hours to minutes\n $LSTss = ($LSTmm - [Math]::Truncate($LSTmm )) * 60 #convert fractional minutes to seconds\n $LSThh = [Math]::Truncate($LST)\n $LSTmm = [Math]::Truncate($LSTmm)\n $LSTss = [Math]::Truncate($LSTss)\n\n write-host (" Local Sidereal Time: " + $LSThh + ":" + $LSTmm + ":" + $LSTss) -ForegroundColor Green\n\n}\n\n### end of functions ###\n\n#Get-SiderealTime # -- will get the current location and time and convert to sidereal time\n#Get-SiderealTime -AskLocation "no" -AskTime "no" # -- will get the current location and time and convert to sidereal time\n#Get-SiderealTime -AskLocation "no" -AskTime "yes" # -- will get the current location and prompt for time. then convert to sidereal time\n#Get-SiderealTime -AskLocation "yes" -AskTime "yes" # -- will prompt for the current location time. then convert to sidereal time\n\nGet-SiderealTime\n<\/pre><\/div>\n\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"
Its been a while since my last post. In that time I have been busy with life stuff. Here is a script I wrote to convert the current time in to sidereal time (GM sidereal time and also local sidereal time)I have modified it in to functions so its a little more user friendly to…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[164,4,165],"tags":[166],"class_list":["post-858","post","type-post","status-publish","format-standard","hentry","category-astronomical","category-powershell","category-sidereal","tag-sidereal-time"],"_links":{"self":[{"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=\/wp\/v2\/posts\/858","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=858"}],"version-history":[{"count":4,"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=\/wp\/v2\/posts\/858\/revisions"}],"predecessor-version":[{"id":862,"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=\/wp\/v2\/posts\/858\/revisions\/862"}],"wp:attachment":[{"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=858"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=858"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jasonstreet.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=858"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}