Evaluating height of trees with high precision for different year

[amirfarshadfar]

Hi

I have a question. Could you please guide me what to do.
I want a DEM file related to the top of trees and vegetations, is it available in any website or utility like Lidar, SAR, .. (with good precision) to be achieved? Which of them do that for me with high precision?

The most important thing is to evaluate the height of trees or have the elevation of top of trees and vegetation. Is there any source for them, even if it is possible to download it or achieve it for different year?

Thanks for your guidance

[rupeshornl]

Hi @amirfarshadfar, Thank you for reaching out to us. The availability of surface elevation and canopy height datasets depends on the region of your interest. I have listed a few selected sources below:

1. GEDI (between 52 N to 52 S latitudes): https://search.earthdata.nasa.gov/search?fi=GEDI
2. ICESat-2/ATLAS (global): https://search.earthdata.nasa.gov/search?fi=ATLAS
3. Data collected from airborne platforms, including unscrewed aerial vehicles) (selected locations):
- LVIS: https://search.earthdata.nasa.gov/search?fi=LVIS
- G-LiHT: https://search.earthdata.nasa.gov/search?fpj=G-LiHT
- Others: https://search.earthdata.nasa.gov/search?q=lidar&fpb0=Air-based+Platforms
You can use NASA Earthdata Search to find other canopy height and surface elevation datasets.

[amirfarshadfar]

Dear

Thanks for your response. I do not need the height of trees and vegetation, I just need a surveyed data like Lidar, SAR, Google Earth (with good precision) … that shows the surveyed data of the area by considering the vegetation and trees to show their z coordinates. Could I find it in any resources?

Because it is a little strange for me that there is no data. I just need a surveyed data (considering the z coordinates) with good precision to shows the z coordinates of the area by considering the trees and vegetation in my case study. Could I find it in any website or resources?
My case study is in Abruzzo in Italy.

Thanks for your responses and guidance
Sincerely
Amir Farshadfar

[ASF - bhauer]

If you are looking for a publically available and recent DEM, your best option is the Copernicus Global and European Digital Elevation Model. Data for the elevation model were acquired through the TanDEM-X mission between 2011 and 2015

Information and sources to download these DEMs can be found using the following links:

https://spacedata.copernicus.eu/collections/copernicus-digital-elevation-model
https://portal.opentopography.org/raster?opentopoID=OTSDEM.032021.4326.3
https://registry.opendata.aws/copernicus-dem/

[NSIDC - mbeig]

You may find this ICESat-2 data product useful, for both terrain and canopy heights from a satellite laser altimeter: https://nsidc.org/data/atl08/versions/6

The vertical precision is likely sufficient. The coverage over your area of interest might not be dense enough, depending upon your application. I recommend using OpenAltimetry (https://openaltimetry.earthdatacloud.nasa.gov/data/icesat2/) to determine whether there are sufficient data in your area.

Mikala

[amirfarshadfar]

Dear

Thanks so much for all your support. I have a question because I am not so familiar with the surveying data.

1- Referring your guidance, I really need a DEM file from my study case (Abruzzo region in Italy) with a very high precision, even maybe around 1m or less. Could you please guide me how could I find it or even if I have to pay for it, what is the website that is related to these kind of data?

2- In addition, for my own assurance, does is it mean that, for example for a “GLO-30” data , whereas the resolution is of 30 m, for every 30 m in the field (30 m length and 30 m width) we have just one elevation and data for that area has been averaged to one average number for a square 30*30 m? Does it mean that I miss a lot of points in a square 30*30 m and receive just 1 point for all the related area?

Thanks for all your guidance and information
I look forward to hear from you
Amir Farshadfar

[ASF - bhauer]

Dear Amir Farshadfar,
Here are some information sources that I hope will answer your questions.

1. Some commercial sources for high-resolution DEMs
https://www.pgc.umn.edu/data/earthdem/
https://www.l3harris.com/all-capabilities/elevation-data-digital-elevation-models
https://www.prnewswire.com/news-releases/capella-space-releases-the-highest-resolution-commercial-sar-imagery-in-the-world-301193732.html#:~:text=Highest%2Dresolution%20%E2%80%93%20Capella%20Space's%2050,1%20m%20x%2025%20cm

2. DEM resolution explained
https://www.jbarisk.com/news-blogs/dem-spatial-resolution-what-does-this-mean-for-flood-modellers/#:~:text=The%20spatial%20resolution%20of%20a,metre%20area%20of%20physical%20land
https://resources.arcgis.com/en/help/main/10.1/index.html#//009t00000004000000
https://storymaps.arcgis.com/stories/302b735ca1954bfb91b3f3265fc469ad

[amirfarshadfar]

Dear

Many thanks for your guidance. I followed the link and it showed the cost for a high resolution 1.0 m or less is very cost effective even for the DSM or DTM data which would be never be included in my budget.
Could you please guide me if there is any website that allows for point measurements and extraction of land and vegetation heights directly free of charge with a high accuracy specifically considering some defining year or even for a specific year?
Please let me know if there is any website considering charges also and I have to pay also?

Thanks for all your guidance and information,
Sincerely,
Amir Farshadfar

[ASF - bhauer]

The only free high-resolution DEM I am aware of is the 1-meter DEM from the US Geological Survey. But it only covers the continental United States, which does not serve your needs.

[amirfarshadfar]

Thanks for all your support and guidance.

- If I could have the z coordinates of the area with the resolution even < 3 m, it would solve the problem. I do not specifically needed the height of trees and vegetations, I just need the z coordinates of some limited points, even by considering the tree and vegetations, to solve the problem. Could you have any suggestion?

- In addition, I fund the https://www.planet.com/ which offers the free download academic account for resolution < 3 m, but I understand that I can use the “Sentinel-2 Tile” option to download the DEM data from the area (Attach 01), but with the resolution > 10 m which is a little low precision for me,

but the “PlanetScope Scene” option could download the data with the resolution < 3 m, which is very good for me, but it does not provide DEM data and if I want to create DEM data from that, I should use another stereo photogrammetry software to create this by myself.

I am really completely unfamiliar with surveying science, could you please guide me what should I do and which software is needed and how could I use the option “PlanetScope Scene” with < 3 m resolution to create DEM data? Does it have a difficult procedure to do it? Do you have any website to do it?

Thanks for your guidance and support,
I look forward to hearing from you,
Sincerely,
Amir Farshadfar