Unihedron SQM-LU-DL User manual

SQM-LU-DL Operator’s Manual
©Copyright 2005 - 2022
Version: 20220119
Company information
Mailing address Unihedron
4 Lawrence Avenue
Grimsby, Ontario L3M 2L9
Canada
Telephone [phone]
Website unihedron.com

Contents
List of Figures ........................................................ 5
List of Tables ......................................................... 7
1 Introduction ....................................................... 9
1.1 QuickStart ..................................................... 9
1.1.1 Settinguptheinstrument......................................... 9
1.1.2 Savingthedatalog............................................. 10
1.1.3 Getting the data from the data log into MS Excel . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.1.4 Othersoftware ............................................... 10
1.1.5 FITSintegration .............................................. 10
2 Measurements ...................................................... 11
2.1 Gettingaccuratereadings ............................................. 12
2.1.1 Seeingconditions.............................................. 12
2.1.2 Lightpollution ............................................... 12
2.1.3 Otherluminancescales .......................................... 13
3 Theory of operation ................................................... 15
3.1 Lightmeasurement................................................. 15
3.2 CommunicationtothePC............................................. 16
4 Specifications ....................................................... 17
5 Hardware connections .................................................. 20
5.1 Batteryoperation.................................................. 20
5.2 DiagnosticLED................................................... 21
6 Software development .................................................. 23
6.1 Writing your own software interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.2 Pascal ........................................................ 24
7 Unihedron Device Manager .............................................. 25
7.1 GettingUDM.................................................... 25
7.2 Installation ..................................................... 25
7.2.1 Systemrequirements............................................ 25
7.2.2 Windows .................................................. 25
7.2.3 Mac ..................................................... 25
7.2.4 Linux .................................................... 25
7.3 Operation...................................................... 26
7.3.1 Startup................................................... 26
7.3.2 Mainscreen................................................. 26
7.3.3 Mainmenu ................................................. 27
7.3.4 Filemenu.................................................. 27
7.3.5 Viewmenu ................................................. 28
3

Contents
7.3.6 Toolsmenu ................................................. 34
7.3.7 Helpmenu ................................................. 42
7.4 Informationtab................................................... 43
7.5 LogContinuous................................................... 44
7.5.1 Import.datintospreadsheet........................................ 49
7.6 Calibrationtab................................................... 50
7.7 ReportIntervaltab................................................. 51
7.7.1 Continuousreports............................................. 51
7.8 Firmwaretab .................................................... 51
7.9 Configurationtab.................................................. 53
7.9.1 Sensorarrangement ............................................ 53
7.10DataLoggingtab.................................................. 54
7.10.1 Vectordatalogger.............................................. 57
7.10.2 Contourplot ................................................ 58
7.10.3 Minimum.datrequirements........................................ 59
7.11Simulationtab ................................................... 59
7.11.1 Simulationfromfile ............................................ 60
7.12Accessoryoptions.................................................. 61
7.12.1 Humidityaccessory............................................. 61
7.12.2 Displayaccessory.............................................. 61
7.12.3 LEDaccessory ............................................... 61
7.12.4 Relayaccessory............................................... 61
7.13Commandlineparameters............................................. 62
8 Commands and responses ............................................... 63
8.1 Commands ..................................................... 63
8.2 Responsedetails .................................................. 65
8.2.1 Readingrequest .............................................. 65
8.2.2 Unaveragedreadingrequest........................................ 65
8.2.3 Linearreadingrequest........................................... 66
8.2.4 Inlinelinearreadingrequest........................................ 67
8.2.5 Unitinformation .............................................. 68
8.3 Calibrationcommands............................................... 68
8.3.1 Calibration information request . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
8.3.2 Lightcalibrationcommand ........................................ 69
8.3.3 Darkcalibrationcommand ........................................ 70
8.3.4 Disarmcalibrationcommand ....................................... 70
8.3.5 Manually set light calibration offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
8.3.6 Manually set light calibration temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
8.3.7 Manually set dark calibration time period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
8.3.8 Manually set dark calibration temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
8.4 SnowLEDaccessory................................................ 72
8.5 Dataloggercommands ............................................... 74
8.5.1 FLASHIDreport ............................................. 74
8.5.2 Loggingpointerreport........................................... 74
8.5.3 Loggingcapacityreport .......................................... 75
8.5.4 EraseentireFLASHmemory ....................................... 75
8.5.5 Logonerecord ............................................... 75
8.5.6 Returnoneloggedrecord ......................................... 75
8.5.7 RetrieveallBinary............................................. 77
8.5.8 Getinternalvoltage ............................................ 79
8.5.9 GetEEPROMstatusregister1...................................... 79
8.5.10 Set and read logging trigger mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
8.5.11 Logging Interval setting response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4Unihedron SQM-LU-DL Operator’s Manual - 20220119

8.5.12 Logging interval reporting period setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8.5.13 Set and read logging Real Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8.5.14 GetRealTimeClockversion ....................................... 82
8.5.15 Putdataloggingunittosleep ....................................... 82
8.5.16 Gatheralarm0datafromRTC...................................... 82
8.5.17 Mutualaccess................................................ 83
8.6 Continuousreportingcommands ......................................... 84
8.7 Setting Interval reporting parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
8.7.1 Interval reporting period setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
8.7.2 Threshold setting for interval reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
8.7.3 Intervalsettingresponse.......................................... 87
8.8 Simulationcommands ............................................... 88
9 Installation ........................................................ 90
9.1 Mechanicalinstallation............................................... 90
9.1.1 Coverselection ............................................... 90
9.1.2 Covercalibration.............................................. 90
9.1.3 Covermaintenance............................................. 91
10 Default settings ..................................................... 92
11 Firmware upgrade .................................................... 93
11.1Details........................................................ 93
12 Calibration ........................................................ 94
12.1Recalibration .................................................... 94
12.2Lightcalibration .................................................. 94
12.3Darkcalibration .................................................. 94
12.4Confirmation .................................................... 94
13 Troubleshooting ..................................................... 95
14 Glossary .......................................................... 100
15 Bibliography ....................................................... 101
List of Figures
2.1 Mpsasinterpretivescale .............................................. 11
2.2 MpsasvsNELM .................................................. 14
3.1 SQM-LU-DLBlockdiagram............................................ 15
4.1 Frontandbackofofunit ............................................. 19
5.1 Wiredconnection.................................................. 20
5.2 Batteryconnection................................................. 20
5.3 Currentprofile ................................................... 21
5.4 DiagnosticLEDtimingdiagram.......................................... 22
5

7.1 Splashscreen .................................................... 26
7.2 Filemenu ...................................................... 27
7.3 FileOpendialog .................................................. 28
7.4 Viewmenu ..................................................... 28
7.5 View:Log ..................................................... 29
7.6 View:Directories .................................................. 29
7.7 Dataloggingheader ................................................ 30
7.8 SetLocationdialog................................................. 31
7.9 Plotterwindow ................................................... 32
7.10Tool:oldlogtodat ................................................ 34
7.11Tool:dattoMooncsv .............................................. 34
7.12Tool:Commterminal............................................... 35
7.13Tool:.datto.kml ................................................. 35
7.14 Tool : .dat to .kml GoogleEarth result . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
7.15Tool:.dattimecorrection............................................. 36
7.16 Tool : .dat local time reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.17RSEalgorithm ................................................... 40
7.18Helpmenu...................................................... 42
7.19Help:About .................................................... 42
7.20Founddevice(single)................................................ 42
7.21Founddevice(multiple) .............................................. 43
7.22USBconnectiondetails............................................... 43
7.23Ethernetconnectiondetails ............................................ 43
7.24RS232connectiondetails.............................................. 43
7.25Informationtab................................................... 44
7.26LogContinuouslyscreen.............................................. 44
7.27LogContinuouslyTriggertab........................................... 45
7.28LogContinuouslyThreshold............................................ 45
7.29 Log Continuously Pre-audio alert . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.30 Log Continuously Alarm for darkness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.31LogContinuouslyTransfertab .......................................... 46
7.32LogContinuouslyAnnotationtab......................................... 47
7.33LogContinuouslyGPStab ............................................ 47
7.34Calibrationtab(initial) .............................................. 50
7.35Calibrationtab(populated)............................................ 50
7.36Reportintervaltab................................................. 51
7.37Firmwaretab .................................................... 52
7.38Firmwareselection ................................................. 52
7.39Configurationtab.................................................. 53
7.40Lightcalibrationconfirmation........................................... 53
7.41Darkcalibrationconfirmation........................................... 53
7.42Sensorarrangement ................................................ 54
7.43Dataloggingtab .................................................. 54
7.44RealTimeClocksettingdialog .......................................... 55
7.45Storagenavigation ................................................. 55
7.46DLRetrievedialogwindow ............................................ 56
7.47DLErasedialogwindow.............................................. 57
7.48Dataloggingpageforvectormodel ........................................ 58
7.49Contourplotof336readings ........................................... 59
7.50Fig:Simulationtab ................................................. 60
7.51Accessoriestab ................................................... 61
9.1 Housing ....................................................... 90
9.2 Examplecovercalibration............................................. 91
6

List of Tables
List of Tables
2.1 Apparent Magnitudes of Known Celestial Objects adapted from [2] . . . . . . . . . . . . . . . . . . . . . . 11
7.2 .dat to Sun-Moon-MW-Clouds values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.3 Storage navigation button descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.4 simin.csvfielddescription ............................................. 60
7.5 Log continuous command line parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
7.6 Select device command line parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
7.7 Select device command line parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
8.1 Summaryofstandardcommands ......................................... 63
8.2 Summaryofdataloggercommands ........................................ 64
8.3 Readingrequestresponse ............................................. 65
8.4 Unaveraged reading request response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
8.5 Linearreadingrequestresponse.......................................... 66
8.6 Inline linear reading request response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
8.7 Unitinformationrequestresponse ........................................ 68
8.8 Calibration information request response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
8.9 Lightcalibrationresponse ............................................. 69
8.10Darkcalibrationresponse ............................................. 70
8.11Disarmcalibrationresponse............................................ 70
8.12 Response for manual setting of light calibration offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
8.13 Response for manually setting of light calibration temperature . . . . . . . . . . . . . . . . . . . . . . . . 71
8.14 Response of manually setting dark calibration time period . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
8.15 Response for manually setting of dark calibration temperature . . . . . . . . . . . . . . . . . . . . . . . . 72
8.16LEDaccessorycommandsummary........................................ 72
8.17LEDaccessoryresponsesummary......................................... 73
8.18 Response of requesting the FLASH chip ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
8.19 Response of requesting the data logging pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
8.20 Response of requesting the data logging capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.21 Response of requesting to log one record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.22 Request to return one logged record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
8.23 Response to return one logged record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
8.24 Response to Binary Retrieve command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
8.25BinaryRetrieverecordcontent .......................................... 77
8.26 Response of requesting internal voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
8.27 Response of requesting EEPROM Status regoster 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
8.28 Request to set the logging trigger mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
8.29 Response of setting or getting the log trigger mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
8.30 Response of viewing or setting logging interval reporting parameters . . . . . . . . . . . . . . . . . . . . . 80
8.31SettingtheRTC .................................................. 81
8.32 Response of getting the RTC values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8.33 Response of getting the RTC version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
8.34 Response of getting the RTC “Alarm 0” value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
8.35 Response of setting or getting the mutual access mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Unihedron SQM-LU-DL Operator’s Manual - 20220119 7

8.36Summaryofstandardcommands ......................................... 84
8.37 Continuous reporting command summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
8.38 Response of all continuous reporting requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
8.39Intervalreport ................................................... 86
8.40 Response of viewing or setting interval reporting parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 87
8.41 Response of request for internal simulation values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
8.42Requestsimulation(S....x)............................................. 88
8.43 Response of setting simulation values (S...x) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
13.1Readingseemtoobright.............................................. 95
13.2Readingis0.00mpsas................................................ 95
13.3CannotFindUDMsoftware............................................ 95
13.4Drivernotfound .................................................. 95
13.5 USB device not found, or more than one device on the same COM port . . . . . . . . . . . . . . . . . . . 95
13.6USBserialnumbergarbled ............................................ 96
13.7LEDdoesnotlightup............................................... 96
13.8Recordingstops................................................... 96
13.9 Meter cannot be found on battery or by PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
13.10UDM improperly lists devices under Windows OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
13.11Meter cannot be found by Windows operating system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
13.12Cannotgetareading................................................ 98
13.13Darkroom-bagreadingsincorrect ......................................... 99
14.1Glossaryofterms.................................................. 100
List of Equations
2.1 MPSAS to cd/m2.................................................. 13
2.2 NELMtoMPSAS ................................................. 14
2.3 MPSAStoNELM ................................................. 14
8.1 RawTemperaturetodegC............................................. 88
8.2 degCtoRawTemperature............................................. 88
8

1 Introduction
Thank you for purchasing the SQM-LU-DL. You will soon be on your way to collecting scientific data.
The SQM series of products have been used in the following applications:
•Quantitatively comparing the sky brightness at different astronomical observing sites.
•Documenting the evolution of light pollution.
•Setting planetarium dome illumination to mimic the skies that people are likely to experience elsewhere in the city.
•Monitoring sky brightness through the night, night-to-night, and year-to-year for astronomical observation records.
•Determining which nights show the greatest promise for finding the ’faintest fuzzies’.
•Calibrating the effect of sky brightness on qualitative measures such as the Bortle Scale or NELM.
•Investigating how sky brightness correlates with the solar cycle and month-to-month sunspot activity.
•Helping to provide local ground truth for future sky brightness prediction with the Clear Sky Clock.
•Helping CCD users make a correlation between the SQM reading and when the background reaches some ADC
level.
•Assisting Sea Turtle researchers in studying the amounts of light in areas where turtle hatchlings are affected by
artificial lights.
•Researching bird-song synchronization with dawn.
•Researching twilight brightness changes with the addition of external Neutral Density filters. Unihedron offers
adapters to attach such filters onto the meter.
•The SQM-LU-DL has the same features as the SQM-LU with the addition of data logging capabilities.
1.1 QuickStart
1.1.1 Setting up the instrument
1. Connect the SQM-LU-DL meter to the computer with the supplied USB cable. Wait for any device drivers to
automatically load (if required). You may have to visit www.FTDIchip.com to get the latest VCP drivers if they
do not get installed automatically.
2. Ensure that your computer date and time is up-to-date.
3. Install and launch UDM (Unihedron Device Manager software supplied on the CD from your File Manager).
4. Click the “Find” button to find attached devices, then click on the SQM-LU-DL that you connected.
5. Click ”Data Logging” tab to go to the setup page.
6. Click the “Set” button in the “Device Clock” area on that page to synchronize the SQM-LU-DL internal time with
your computer time and date.
7. Set the repetition time for the readings in the “Trigger” section on the left side of the window. A good rate is “every
5 minutes”.
8. Keep the SQM-LU-DL connected to the computer for a couple of hours to charge up the internal Supercap; this
allows it to keep the time and date clock running while you are moving from your computer to the measurement
site. A fully charged meter will keep the clock running for a few days unpowered.
9

1 Introduction
9. Disconnect the SQM-LU-DL from the USB cord and plug in the battery pack within eight hours, the LED will come
on for three seconds to indicate that the unit woke up and is working. The LED will come on every minute for a
few seconds, you can use this to determine if the unit is still properly powered. Note: beware that using a “USB
charger” instead of the battery pack may cause problems since some of these chargers make the SQM-LU-DL think
it is connected to a computer instead of a battery, and some other chargers do not have the surge capacity to allow
the SQM-LU-DL to start up properly.
The device is now recording.
1.1.2 Saving the data log
Follow these steps to retrieve the logged data from the SQM-LU-DL:
1. Connect the SQM-LU-DL to the computer with the USB cable.
2. Launch the UDM program and find your device as before.
3. Select the “Data Logging” tab.
4. Click “Retrieve All” and follow the instructions on that page.
5. ONCE YOU’VE CHECKED THAT THE DATA IS SAVED TO DISK PROPERLY, and you want to clear the
data-logger memory in preparation for a new set of records, you can erase the old memory. Warning this step
cannot be undone!
1.1.3 Getting the data from the data log into MS Excel
1. Find the log data. It will be in a *.dat file, where the * will give you the date and time
2. In the Tools pulldown in the UDM program, use the “.dat to Moon .csv” function to convert the log file to a *.csv
file. Do not erase the original log file, because it contains some information (e.g., the type and serial number of your
SQM) that is not converted to the csv file.
3. Open the *.csv file in Microsoft Excel.
4. In Excel, highlight the data, then in the “Data” pulldown, use the “Text to Columns” function to convert the data
into columnar format; the divider is a semicolon.
5. Your data is now in nice columns by date and time, so you can plot it out as you wish.
1.1.4 Other software
•If you are using Windows, you may want to use Knightware SQM-Reader from www.knightware.biz/sqm .
•The CD contains examples of software (Perl, Python, etc.) for various functions that connect to the meter.
1.1.5 FITS integration
Some programs (listed below) gather information from the Unihedron Sky Quality meter products and insert that data
into the Flexible Image Transport System (FITS) header.
•MaxPilote (Freeware) incorporates SQM readings from an SQM-LE/SQM-LU into the FITS header while at the
same time provide constant readings in a live and updated Data Window.
•CCDAutoPilot
•FITS4Win2 uses the MPSAS keyword for sorting and filtering image files.
10 Unihedron SQM-LU-DL Operator’s Manual - 20220119