Phenological Eyes Network (PEN)--- Connecting Satellite Remote Sensing to the Ground-Level Ecosystems ---
What does PEN stand for?
Leaflet: PDF / PPT / JPEG (page1, page2, page3, page4)
Review article in AsiaFlux Newsletter (2007)
If you have a plan to use PEN data for your presentation or article, please contact preliminarily. You also need to contact the site PI.
Science Daily News about AHS site.
BBC article about AHS site.
HVT site was established with a support by University of Hawaii.
YGT site was established with a support by Center for Environmental Remote Sensing, Chiba University.
PFA site was established with a support by JAMSTEC-IARC project.
UAK site was established with a support by JAMSTEC-IARC project.
AHS site was established with a support by UK-Japan project.
A new article referring to PEN in FluxLetter (p. 13-).
PHENOLOGICAL PHOTOGRAPHS OF SIBERIAN LARCH FOREST FROM 1997 TO 2000 ... by Dr. Rikie SUZUKI in JAMSTEC
2005.2.27-7.6:We apologize that PEN mail-address for information and inquiry was out of order in this period.
2004.9.8:TFS site was encountered with Typhoon attack! The system of this site has been stoped.
ID site name plant type data note AHS Alice Holt DBF recent original summary log 2009-, ADFC. Managed by Forest Research and U. Edinburgh. AI7 AIST 7th Building urban recent original summary log 2004 only. Sky ADFC only. BDX Bordeaux agric recent original summary log ADFC EGT EGAT Tower, Thailand mixed recent original summary log 1999-2002. film camera only. GDK Gwangneung DBF recent original summary log 2009-, ADFC, HSSR FHK Fuji-Hokuroku DNF recent original summary log 2005-, ADFC, HSSR, SP. Managed by NIES and AIST FJY Fuji-Yoshida ENF recent original summary log 2009-, ADFC Managed by FFPRI HVT Hawaii Volcano Thurston EBF recent original summary log 2012-, ADFC. Managed by U. Hawaii. JND JND,China rice paddy recent original summary log 2010-, ADFC. Managed by NIAES, JAMSTEC and U. Tsukuba. KBF Kranzberger forest DBF recent original summary log 2010-, ADFC Managed by Technical University of Munich. KEW Kiryu Experimental Watershed ENF recent original summary log 2004-, ADFC, HSSR. KFS Biyala, Kafr El Sheikh, Egypt (N31:10:16, E31:09:31) rice paddy recent original summary log 2011-, ADFC. Managed by U. Tsukuba. KIZ Karuizawa KIZ recent original summary log 2009-, ADFC. LBR Lambir Hills EBF recent original summary log 2009-, ADFC. MSE Mase Flux site rice paddy recent original summary log 2005-, ADFC, HSSR. Managed by NIAES, U. Tsukuba, and AIST MMF Moshiri Mixed Forest Site Mixed forest recent original summary log 2010-, ADFC. Managed by Hokkaido U. and U. Tsukuba MTK Mt. Tsukuba Mixed forest recent original summary log 2008-, ADFC; Tsukuba PFA Poker Flat Research Range Fairbanks Alaska ECF recent original summary log 2011-, ADFC. Managed by JAMSTEC and IARC SSP Spasskaya Pad DNF recent original summary log 1997/08/25-2000/10/15, by Rikie Suzuki, JAMSTEC RHN RIHN urban recent original summary log 2005-2006. Sky ADFC only. SGD Sugadaira grassland recent original summary log 2005-, ADFC. Managed by Tamagawa U. SHA Seoul Heonilleung Alnus Forest Decidious forest recent original summary log 2010-, ADFC. TFS Tomakomai Flux Site DNF recent original summary log 2004. Destroyed by a typhoon. Managed by NIES. TOM Tomakomai DNF recent original summary log 200?- ADFC, HSSR. Managed by Gifu U., Hokkaido U. and NIES TGF TERC Grass Field grassland recent original summary log 2003-, ADFC, HSSR, SP. Managed by U. Tsukuba and AIST. TKC Takayama Conifer Flux Site ENF recent original summary log 2007-, ADFC, HSSR. Managed by Gifu U. TKY Takayama Flux Site DBF recent original summary log 2003-, ADFC, HSSR, SP. Managed by Gifu U., U. Tsukuba, and AIST. TSE Teshio CC-LaG Experiment Site Mixed forest, DNF recent original summary log 2006-, ADFC. Managed by Hokkaido U., U. Tsukuba and NIES UAK University of Alasla Fairbanks ECF recent original summary log 2010-, ADFC. Managed by JAMSTEC and IARC YGT Yatsugatake Site DNF recent original summary log 2011-, ADFC. Managed by JAMSTEC and Chiba University
3-character ID is taken from Asia/JapanFlux rule.
FJH has been renamed to FHK.
TFS has been renamed to TMK in Asia Flux community, but we still keep using TFS for convention.
- ADFC: Automatic Digital Fisheye Camera
- AIST: National Institute of Advanced Industrial Science and Technology
- DBF: deciduous broadleaf forest
- DNF: deciduous needleleaf forest (in our case, larch forest)
- ENF: evergreen needleleaf forest
- FFPRI: Forestry and Forest Products Research Institute
- HSSR: Hemi-Spherical Spectral Radiometer
- NIAES: National Institute for Agro-Environmental Sciences
- NIES: National Institute for Environmental Studies
- RIHN: Research Institute for Humanity and Nature
- SP: SunPhotometer (Skyradiometer)
- TERC: Terrestrial Environment Research Center, Univ. Tsukuba
* Map of PEN sites
Satellite remote sensing (RS) is a strong methodology in the study of terrestrial ecosystems. For example, RS is used in scaling up of the ground measurements of carbon flux, water flux, biomass, etc. from a site scale to a regional or global scale. RS provides numerical regional ecological models with information for initial conditions, boundary conditions, and validation. For the sake of it, various new satellite sensors have been designed and launched. They are now delivering a lot of high-level products regarding to the terrestrial ecology, such as new vegetation indices, LAI, FPAR, phenology, GPP, and NPP.
However, in the ecological standpoint, these RS methodology has not enough checked or validated on the ground level. Because an essential characteristics of ecosystem is its dynamism (especially the seasonal change, or "phenology"), the accuracy, quality, and interpretation of the RS data should be also studied dynamically. For the sake of it, a stable, continuous, long-term, and multi-ecosystem ground validation network is desired. Of course, the flux observation networks such as AsiaFlux have potential to contribute to it. However, because RS observes vegetation's optical characteristics rather than carbon or heat flux, we need to include optical (spectral) observation in the validation of ecological RS. We believe that the ecological interpretation of RS data is possible only if it is based on a careful theoretical and experimental study of the relationships between optical characteristics and ecological structure (or function), using the quality-controlled RS data considering the relevant noise factors such as cloud contamination or atmospheric aerosols.
With this background stated above, we have started the "Phenological Eyes Network (PEN; Tsuchida et al., 2005)." PEN is a network of ground observatories for long-term automatic observation of the vegetation dynamics (phenology), vegetation's optical properties (such as spectral reflectance), and the atmospheric optical properties (such as aerosol optical thickness). Most PEN ground sites have been set up at the AsiaFlux sites. The collaboration of PEN and AsiaFlux is critically important in the interpretation of the optical signals captured by RS in terms of ecology (especially the terrestrial carbon/water cycles).
PEN's scientific targets
phenologyPEN has been supported by the Global Environment Research Fund (S-1: Integrated Study for Terrestrial Carbon Management of Asia in the 21st Century Based on Scientific Advancement) of the Ministry of Environment of Japan.
photosynthesis (LUE, FPAR and PAR)
leaf area index (LAI)
validation, calibration, and assimilation of satellite data
radiative temperature and its directional dependency
radiative transfer models / carbon and water cycle models
Because the goal of PEN is to collect long-term quality-controlled multi-site data, the main instruments should be stable, robust, and low-cost. Based on this principle, we selected and designed the following three types of instruments: the Automatic-capturing Digital Fisheye Camera (ADFC), the HemiSpherical Spectro-Radiometer (HSSR), and the sunphotometer (SP).
ADFCADFC is a combination of a high-quality digital camera (Nikon CoolPix series), a fish-eye lens (Nikon FC-E8), a water-proof housing case, and a control system with a personal computer. It captures images of the sky, the canopy from above and below, the forest floor, and shoots of typical species with short intervals (2 minutes to 24 hours, depending on the target). These images provides information about cloud condition at the satellite's observation, vegetation phenology, snow pack, tree cover, and LAI.
HSSRHSSR is a hyper-spectral radiometer in the visible and near-infrared region (MS-700 of Eko Instruments Co. or PGP-100 of Prede Co.). In order to catch both incoming and reflecting radiation with a single radiometer, we developed a computer-controlled rotating stage in collaboration with Hayasaka Rikoh Co. If the HSSR is mounted on the rotating stage, it can be directed upward and downward consecutively with a short interval of time at a same position. Thus we can obtain the spectral features of the vegetation canopy with fine-temporal and fine-spectral resolution. By using such data, we can check the spectral observation of RS. Moreover, we can simulate various types of spectral indices (such as NDVI, EVI, PRI) with arbitrary spectral response of every specific satellite sensors.
SPSP is a spectral radiometer with a small field-of-view and pointing functionality. We use POM-02 of Prede Co. We can estimate optical properties of the atmosphere which are needed for atmospheric correction of the RS data. It can provide quantitative information about atmospheric pollution or aerosol dust (such as the Yellow Sands), both of which may have some direct or indirect impacts on the ecosystems.
Other sensorsIn addition to the above-mentioned main instruments, in some sites, we are making observation of environmental ecophysiological properties including incoming PAR (direct and diffuse), transmitting PAR, leaf phenology, LAI (LAI-2000, fisheye image, laser profiler, and litter trap), leaf-level optics, leaf-level physiology (LI-6400, pigments, C/N, LMA).
Details on the system (in Japanese)
Most data taken by these sites have been stored in the PEN's database server. The original data are open to the PEN community member (anybody can join if they want) and the summary or edited data are open to the public.