Sun Sky Lunar Multispectral Photometer

Remote sensing instruments




Numerous applications take advantage of the aerosol charateristics and atmospheric optical properties provided by the CE318 photometer

  • Climate and climate change studies
  • Air quality monitoring and forecast
  • Near real time detection of volcanic ash plumes
  • SDS (Sand Dust Storm) monitoring and forecast
  • Calibration of satellite borne instruments
  • Validation of satellite aerosol products
  • Calibration of Ocean Color satellite borne instruments

User's benefits

Precision and high reliability

  • Day and night measurements
  • High angular resolution tracking
  • Most wide-spread and scientifically validated multiband photometer
  • Several standard and entirely automatic scenarios of measurements
  • High calibration stability on the long term, even in harsh climatic conditions

Proven robustness under any climate

  • More than 1500 instruments operating around the world
  • Continuous operating even under extreme climatic conditions
  • Reinforced protection against lightning
  • High robustness and resistance to corrosion
  • Very low maintenance

Flexibility of use

  • Suitable for long-term installation within observation networks
  • Suitable for field campaign measurement
  • Operates with a minimum of human attendance in a fully automated way with its own solar generator
  • Large number of communication means: RS232, USB, mobile phone (GSM/GPRS), Satellite for isolated locations


MicroAmps® technology

The CE318 photometer takes advantage from the unique Cimel MicroAmps® technologies, that result in meeting several very demanding yet complementary specifications:

  • Minimize electrical power consumption
  • Use secure, highly redundant communications protocols
  • Maximize the versatility of printed circuit boards
  • Minimize the number of connectors

These Micro-Amps® technologies result in CE318 photometer exceptional performances widely proven under any sort of climate, in terms of operating reliability.

Optical sensor head

  • Includes two detectors  to cover the entire spectrum from 340 nm to 1640 nm :
    • Silicon photodiode for UV and visible spectrum
    • InGaAS detector for NIR
  • Narrow and precisely defined field of view (0.65° half angle)
  • High precision single-band filters inserted in the optical paths
  • Motor-driven filter wheel for nine or twelve single band filters
  • Additional motor-driven filter wheel for polarization filters in the optical path (models with polarization)
  • Extremely sensitive, low-noise electronic conversion, operating in a large temperature range
  • A dual external collimator to eliminate stray lights and allow aureole measurements up to a 2° scattering angle from the sun
  • High sensitivity four quadrant detection for sun and moon tracking

 High precision robot

  • Two axes with high-resolution driven systems
  • Unique proprietary mechanical backlash adjustement technology

Control unit  

  • All control, data acquisition, storage and communication functions are integrated within a single metallic and sealed control box
  • Robot control with very high resolution for fast ans smooth moves
  • high precision tracking
  • Equipped with a built-in barometer to automatically register the local atmospheric pressure
  • Input for a pyranometer for acquisition of the global solar radiation
  • The internal memory includes a flash memory ans an SD card (no risk of data loss)
  • Large backlit built-in display for easy reading and navigation through user-friendly menus in all lightning conditions
  • A keyboard display interface is available to the user for configuring the instrument and checking operation
  • Built-in GPS for automatic data localization and time synchronization



The instrument may be configured according to model and application using a large number of available scenarios for:

  • Direct solar measurements: sun tracking and triggering of a multi-band measurement triplet
  • Sky measurements: positioning according to a principal plan or  almucantar or hybrid scenarion and triggering of a measurement cycle at several angles
  • Nighttime lunar measurements (when moonillumination is higher than 50%): periodic lunar tracking and triggering of a multiband measurement triplet
  • Ground lake and sea measurements : special BRDF and SEAPRISM scenarios
  • Measurement data are automatically processed and stored in the control unit memory



The control unit supports 4 communication means:

  • RS-232 :  Automatic real time transfer, through a RS-232 fixed line connection. It requires a local PC (not supplied) equipped with PhotoGetData software
  • USB: Manual collection, through a short USB cable (temporary connection only). It requires a laptop equipped with PhotoGetData software
  • GPRS/W-CDMA :Automatic real time transfer by mobile phone to a FTP site with a standard GPRS (Sim card is not supplied). Minimum capacity is 10 MB/Month
  • DCP (Data Collected Plateform) : This mean is in option , it does not operate together with RS-232. For automatic operation on isolated sites, a DCP transmitter may be added (see Options) with plug & play connection to automatically send data via the Data Collection System through meteorological satellites like Meteosat / MSG (Europe), GOES (Americas), FengYun (China), INSAT (India), Himawari (Japan). The user must request time slots to the DCS satellite operator


  • Data acquisition

The photometer is supplied with PhotoGetData software, that may be installed on a PC (not supplied), equipped with Windows (7, 8, 10) operating system.

PhotoGetData features the following functions:

-Automatic or manual acquisition of raw measurement data (digital counts, temperature, pressure, battery, tension, humidity) either in continuous mode or from time to time

-Automatic conversion and storage as ASCII files

-Automatic data display

-Set up of photometer parameters

-Update of photometer firmware

  • Data processing: AERONET

Several algorithms have been developped by the scientific community for this process.

AERONET is recognised by the worldwide scientific community as the reference network for the production of aerosol and atmosphere physico-optical parameters.

It operates an almost fully automated process that generates operational checks and quality-assured final products.

See AERONET site (www.aeronet.gsfc.nasa.gov) for more details.

Cimel data processing software : IAAMS (optional)

IAAMS is the calibration tool for the photometer and the LiDAR.

Cimel can provide the free data processing software, IAAMS, that processes the raw data acquired through PhotoGetData.

All algorithms included in IAAMS are published in peer reviewed scientific journals.

In particular, the inversion algorithm has been developped by the Grupo de Física de la Atmósfera of the University of Granada.

The IAAMS software must be installed on a PC (not supplied) equipped with Windows  operating system (7 or 8).

IAAMS offers the following features:

  • User friendly graphic interface
  • Fully automated operation (near real time) or manual mode
  • Application of calibration coefficients
  • Cloud detection and data filtering
  • Retrieval of aerosol and atmosphere physico-optical parameters
  • Graphic and table  display

IAAMS is able to retrieve the following parameters:

  • Daytime (sun) and nighttime (lunar) spectral Aerosol Optical Depths (AODs) and precipitable water vapor content
  • Aerosol size distribution (VSD)
  • Complex refractive index
  •  Percentage of spherical particles
  •  Volume concentration
  • Effective radius of particles
  • Spectral phase functions and  asymmetry parameters
  • Single Scattering Albedo
  • Possibility of combining photmeter data with data from a Cimel aerosol LiDAR to generate improved aerosol vertical profiles

Standard technical features

Specifications Value
Sensor head
Full scale digital count precision  < 0.1%
 Half field of view  63°
Smallest scattering angle (from the sun) for sky measurements
Spectral range 340 to 1640 nm standard (depending on sensor head model)
Long term drift of single band filters’ transmission rate  < 1%/year
Control Unit Firmware Single firmware on all photometer models with all available scenarios
Data coding 32 bits
User's interface Touch keyboard

Backlight graphic display

Input and output connectors On a single terminal block
Communication outputs RS-232, USB, GPRS/W-CDMA (optional) (to FTP site)
-RS-232 cord for continuous connection ot a PC

-USB cord for temporary connection to a PC

-3 m cord (up to 100 m total length : see options)

-3 m cord with USB connection on PC side

Storage -Flash memory (4 MB) : 6 to 8 weeks data storage, for autpmatic transfers

-SD card 8 GB (32 GB in option)

Additional measurements -Rain detector


Barometer (precision 1 hPa)

-Temperature and humidity inside the protection enclosure

Additional input Thermopile pyranometer (not supplied)
Robot Number of axes  2 axes : azimuthal and zenithal
Angular scanning Whole sky angular scanning:0°-360° in azimuthal angle, 0°-180° in zenithal angle
Resolution/ tracking precision  0.003°
Sun/Moon tracking accuracy (automatic active  tracking)  0.01°
Power supply  Solar panel 5 W solar panel embedded in the  protection enclosure of the control unit
Main Power adapter (110 - 240 V)
Batteries 8 Ah sealed lead gel batteries set (to be placed outside of the control unit in the protection enclosure)
Environmental conditions Temperature range  - Without cold weather option : -30°C to 50°C

-With cold weather option: -40°C to 50°C

Humidity range  0 to 100% RH
Infrastructure Tripod, with protective enclosure
Packaging Fly case for transportation
Packing dimensions 66 cm x 52 cm x 47 cm
Total weight (including tripod infrastructure) 38 kg



Post processing and deployment

CE318 deployed in Tamanrasset (Algeria)

Deployment of CE318 photometers on a scientific observation base

CE318 deployed in polar environment

Models & Options

Head models

Several sensor head models are available, according to the desired application:

Reference Description Characteristics Applications
 CE318-TS9  Standard model  340, 380, 440, 500, 675, 870, 937, 1020, 1640 nm  Standard
CE318-TP9  Polarized model  340, 380, 440, 500, 675, 870, 937, 1020, 1640 nm

Polarization in 3 directions

 Polarized & non polarized measurements
CE318-TU9 BRDF measurements 380, 440, 550, 675, 740, 870, 937, 1020, 1640 nm  Satellite calibration
CE318-TU12   BRDF measurements  415, 440, 490, 555, 675, 702, 740, 782, 870, 937, 1020, 1640 nm Satellite calibration
CE318-TV12 OC


Measurement of radiances emerging from the sea water surface 400, 412.5, 442.5, 490, 510, 560, 620, 665, 779, 865, 937, 1020 nm Ocean Color Program (Satellite validation)
TV12 LC Measurement of radiances emerging from the lake water surface 412.5, 442.5, 490, 510, 560, 620, 665, 681, 709, 865, 937, 1020 nm Lake Color program


Sales reference Description Characteristics Applications
15 m cabling
PC line kit for 15 m cabling length -15 m RS-232 cord

-RS-232-USB converter

Continuous connection to a PC
100 m cabling
PC line kit for cabling length up to 100 m -RS-232 connection kit

-100 m special cable to be cut ar desired length

RS-232-USB converter

Continuous connection to a PC
Satellite-KIT T440-KIT-318 DCP satellite transmission system (Satlink) Transmitter, protection enclosure, dedicated solar generator, 2 m mast, anchorage system
Very cold weather I318-HEA-A10 Adaptation for very cold weather including heating robot -Robot with heating (main supply

-10 m cable to facilitate indoor installation of the control unit

Automatic operation at high altitude or polar sites
iAAMS Cimel data processing software   Air quality

Aerosol monitoring