Radiometer Status Display

The various status displays in the Radiometer Status group box are:
•	Software Version: Indicates the version number of the radiometer PC software 2CH.EXE for reference (the host software version is printed in the main window caption).
•	Instrument ID: The radiometer identifies itself by sending the instrument ID to the host when a connection is established (e.g. RPG-HATPRO, RPG-LWP, RPG-LWP-U, etc.).
•	Controllers: Lists the status of the four instrument controllers:
o	The main controller handles all communication activities between the radiometer PC and the radiometer hardware. 
o	The elevation stepper controller generates the driving signals for the elevation scanning paraboloid mirror. It also provides the initialization procedure for moving the mirror to its index position at system power up.
o	The radiometer azimuth controller commands the optional azimuth positioner. If no azimuth drive is installed and attached to the controller, the display ‘not responding’ is shown.
o	The receivers controller diplay indicates, if a receiver module is installed (1) or not (0) for receivers 1 and 2.
•	GPS: Indicates if a GPS clock is installed or not and the global position of the radiometer location (at least 5 GPS satellites have to be visible to provide this information). Also the radiometer time and date are displayed. 
•	Real Time Clock: Displays if the radiometer PC’s real time clock (RTC) is resonding. The RTC is essential for all radiometer operations that are related to time measurements.                       
•	Flash Disk Capacity: The radiometer PC is equipped with a flash memory hard disk (no movable parts) called DOM. Its capacity – when empty - is 1.0 GBytes. The status indicates how much memory (measured in kBytes) is left for the backup of measurement files. If the remaining free memory is less than 20 Mbytes, the backup files should be flushed. When 10 MBytes are reached no further file backup is performed.
•	Infrared Radiometer: If the optional infrared radiometer is installed the infrared temperature is displayed here. This data can also be used as input for retrievals. In combination with the temperature profiles the cloud base height can be determined. The IR temperature provides a cloud flag (at least for non cirrus clouds).
•	Temperatures: Four temperature sensors are implemented:
o	The environmental temperature sensor is located outside of the radiometer box below the dew blower. The sensor data is an important parameter for the absolute calibration cold target temperature measurement.
o	The ambient temperature target sensor precisely measures the built-in calibration target temperature. The precision of that sensor is essential for ALL calibration procedures. Up to two ambient target sensors can be implemented.
o	Receiver1 / Receiver 2: These temperature sensors reflect the physical temperatures of the receiver modules which are stabilized to an accuracy of < 0.05 K. Typical sensor readings are around 40°C. The thermal receiver stabilisation is continuously monitored. If the receiver temperature is kept constant to within +/- 0.05 K, the status indicator on the right of the temperature display is green. If it turns to red the stability is worse than this threshold. In addition the actual stabilisation values are listed. The colour of the stability status indicator turns to yellow if not enough temperature samples have been acquired to determine the stability.
•	Other Sensors: Three additional sensors are monitored:
o	Barometric Pressure: The pressure sensor measures the barometric pressure in mbar (accuracy ±1.0 mbar). The data is used in the determination of the precise boiling temperature of the liquid nitrogen coolant used in the external calibration target during absolute calibration.
o	Relative Humidity: The sensor is located below the dew blower system outside of the radiometer box. The data is used to control the dew blower fan speed when reaching a software predefined threshold. Its accuracy is  ±5%.
o	Rain Flag: Status of the rain sensor. The flag is used to operate the automatic shutter system and is monitored with all measurements to distinguish between rain events and no rain.
o	X- and Y-inclinometers are not supported anymore.
•	Calibrations: Here the status of automatic calibrations (gain calibration, noise calibration and sky tipping) is monitored during measurements. All calibration data is automatically logged in the CAL.LOG file located in MY_DIRECTORY\RPG-HATPRO\. The contents of that file can be inspected with the Display Automatic Calibration History menu.
•	Elevation / Azimuth Scanners: The data displayed here is the current position of the elevation and azimuth scanners. The azimuth value only shows two positions, 0° and 180° if no azimuth driver is installed. 0° means that the elevation scanner is currently moving in the quadrant marked by the orange arrow on the radiometer box. 180° indicates that the elevation scanner is moving in the other quadrant (only relevant for sky tipping bidirectional mode). Also displayed is the status of the boundary layer scan.
•	Measurement: During measurements this group box displays details like the file name of the current measurement, when the measurement was started and when it will end, the time reference (UTC or local time), if file backup is enabled on the radiometer PC and the batch repetition factor as well as the current processed MDF.