assembly number
Atmospheric, oceanic and land remote sensing exchange QQ group: 831106035 . Everyone is welcome to join. In the group, you can discuss issues related to remote sensing of the atmosphere, land, ocean... and share resources related to the above interests. I wish you all a happy study.
introduction
CALIPSO (Cloud–Aerosol Lidar and Infrared Path nder Satellite Observation) is a NASA and CNES sun-orbiting Earth reconnaissance satellite. CALIPSO is equipped with three zenith field-of-view instruments (CALIOP, IIR, WFC) for observing aerosols and micron-sized cloud particles. Visible and near-infrared polarization sensor lidar carried by CALIPSO is used to observe the phase state of Earth's aerosols and clouds. The satellite data distribution formats are HDF and HDF-EOS, and there are different levels of data products to choose from. For many entry-level users, downloading data is sometimes troublesome because no one leads researchers who are completely self-exploring. Because the download of earth observation data is not as simple as downloading movies from Thunder. Next, I will share with you the data download of CALIPSO.
download
There are five ways to order CALIPSO data (the data are all free):
- https://eosweb.larc.nasa.gov/HBDOCS/langley_web_tool.html, the Reverb Search Tool
- http://reverb.echo.nasa.gov/reverb, and for Level 1 and 2 Lidar data only, the CALIPSO
- https://www-calipso.larc.nasa.gov/search/login.php, if Search and Subset Tool
is not registered, you need to register a user first, otherwise the data cannot be downloaded. - https://subset.larc.nasa.gov/calipso/index.php
The fourth method can retrieve data according to the time range, etc., which is more suitable for downloading data on a large scale and is very useful.
5. The second method is used. Sometimes the network access is very slow, and the website will jump to NASA’s [Earth Data Search Site] https://search.earthdata.nasa.gov/search , use this website to search and download Data is more convenient.
If the above 1-4 cannot download data, you can use method 5, and method 5 is also very useful if you are used to it. Method 4 can only download 2000 files each time. Although method 5 is also 2000 files each time, if your data cycle is long and there are many data files, it will automatically divide the data into multiple groups of data with each group not exceeding 2000 files for download. So method 5 is also a very good download method.
Note: If you receive an ftp link, be sure to change it to https, the download speed difference is not a little bit.
data download
Take the fourth way as an example, this kind of search data is very convenient.
Open the website: ASDC
login, registration without user name,
select the data product, time, scope, etc. you need,
and then submit your choice. The time to receive the download connection varies according to the number of hdfs. If it is 1 hdf, it takes about three You can receive the system reply email within minutes.
The first email
is an email with a download link.
The download method can be downloaded using ftp transfer software. Here, it is recommended to use FileZilla, which is free and easy to use.
##HDF file visualization
For the downloaded HDF file, you can use the IDL package provided by the official website to read it. It can also be read using HDFView software or ccplot. The author uses the self-compiled ccplot to read and visualize (draw) the hdf data. In the previous blog post, there is an introduction to the compilation method of ccplot.
epilogue
The above content is all the practical operation plan summed up by the author after more than a week of groping and wandering. I hope you can avoid detours after reading this blog post.