For phones and tablets
Android™ 4.4 and above, iOS 8 and above, or Windows 10 (ARM & x64).
bytran requests several permissions for its operation under mobile platforms.
The Windows Phone version does not offer Image and Data sharing.
Desktop versions currently do not include and installer and contain unmodified mobile interface. Additional information about previous releases is available in the   Archive
(1) Linux versions are currently unavailable due to the issues linking SSL libraries to access HITRAN over secure socket layers.   This issue will most likely be addressed with the release of bytran 1.5.   (2) The serial port profile Bluetooth connectivity used for remote control may not work (or requires additional setup) under Ubuntu and Mac OS.
Example usage of the original bytran version 1.0 Alpha on a cell phone
(May 12, 2016)
bytran is an application for calculating atmospheric and molecular absorption spectra using the HITRAN database and the line-by-line method.   The concentrations of molecules, optical pathlength, total pressure, temperature, and other input parameters are used to model the gas mixture optical transmission spectra as a function of wavelength.
Among other features bytran can be controlled remotely and supports optional usage of SensorTag, Sense Hat, and cell phone sensors for calculations using empirical readings of ambient total pressure, temperature and humidity (H2O vapor concentration) †.   For more information read the overview of bytran, the bytran publication and the change log of the bytran releases.
† The usage of cell phone sensors is currenly limited to the Android operating system due to the limitations of the Qt environment.
Kielkopf algorithm approximation of the Voigt profile for fast low accuracy estimates -|- HITRAN database storage options -|- Wavenumber resolution settings
Kielkopf low accuracy algorithm for the calculation of the Voigt profile was added to bytran which may be useful for fast calculations where high accuracy is not required.
The HITRAN database may now be stored and accessed in a binary format as an option.   The binary mode was introduced to speed up the HITRAN database read times.   The HITRAN database settings window allows selecting the HITRAN database storage mode (ASCII, binary, or both ASCII and binary) as well as to select which files (ASCII or binary) are to be used in calculations.   For phones running Android an option was introduced to be able to store the HITRAN downloaded data, the configuration file and the calculation results on a removable SD card under the Android operating system.
The wavelength resolution may now be specified as:
( 1 )   An absolute value in current wavelength units
( 2 )   As the number of data points along the wavelength span
( 3 )   As a combination of options ( 1 ) and ( 2 ) above where the coarser resolution specified by the two methods is used in calculations.  This third option was introduced to automatically reduce the number of data points for shorter calculation wavelength spans to speed up the calculations for narrower wavelength spans.
Remote connection to bytran to run calculations and retrieve data
Bluetooth -|- WebSockets -|- Serial Port
Remote control of bytran may be carried out over classic Bluetooth, WiFi / Ethernet (using WebSockets) or the Serial port.   The communication is carried out using the newly introduced bytran communication protocol and enables remote execution, and retrieval of calculation results.   The following links provide information on how to test and use bytran connectivity over Bluetooth, WebSockets, or the Serial Port.
Line-by-line calculations using measured meteorological data -|- Sensors may be used to provide empirical values of total pressure, temperature and water vapor concentration as input instead of manual entry -|- SensorTag, Cell phone built in sensors, Sense HAT
SensorTag is a keychain size coin battery operated bluetooth device containing temperature (TMP007 and BMP280, ~ ±1 °C accuracy), pressure (BMP280, ~ ±1 hPa accuracy) and humidity (HDC1000, < 3% accuracy) sensors.   Starting with version 1.2 bytran is able to connect to SensorTag and access its sensors.   The SensorTag may be purchased directly from Texas Instruments or its distributors.
Bytran is able to access cell phone built in sensors however this support is limited to the thermometers and barometers under the Android operating system due to the present limitations of the Qt environment.   Future bytran editions will likely include custom code to suppport the iOS operating system and the humidity sensor.   A search of cell phones with a barometer, thermometer and/or humidity sensor may be performed here.
Starting with version 1.3 bytran supports the Sense HAT add-on board for Raspberry Pi to measure ambient total pressure (LPS25HB, accuracy of 10 to 100 Pa), temperature (HTS221, < 0.5 °C accuracy) and humidity (HTS221, < 3.5% accuracy) for input into the line-by-line calculations instead of the manual entry.
To report a bug or suggest a feature please email us: