TimeSync-Legacy

Requirements

• Windows PC
• Python
• GDAL (best if associated with Anaconda or OSGeo4W)
• Google Earth Engine (GEE) account
• Google Drive account associated with GEE
• Program to edit Access .mdb files (MS Access, OpenOffice Base?)

Getting the Package

The package can be downloaded with this URL: https://github.com/eMapR/TimeSync-Legacy/releases/download/v1.0/TimeSync-Legacy-Package_v1.0.zip

It contains these files and directories:

• tsl_v3.9.8.0
• tsl_db_demo.mdb
• tsl_db_template.mdb
• tsl_gee_stack_unpacker.py
• tsl_image_list_maker.py

Once the file has been downloaded unzip it to a place that makes sense for your system of organization. It should be thought of as software and all the files in the folder should stay together. It is generic and can be used for many TimeSync projects.

All version and updates can be viewed in the repository release section.

Steps

1. Upload a Shapefile to GEE
2. Run Source Data GEE Script
3. Download Source Data from Google Drive
4. Run Source Data Preparation Python Script
5. Make Source Image Lists
6. Create Project Database
7. Load Project Database in TimeSync-Legacy

1. Upload a Shapefile to GEE

You need to create a shapefile of your study area and upload it to GEE. It will define the area of TimeSync-Legacy data that is exported from GEE. It should be uploaded as an asset. Please see the GEE guide on importing shapefiles as assests

2. Run TimeSync-Legacy Source Data GEE Script

Add the eMapR public code repository to your GEE account. Visit this URL: https://code.earthengine.google.com/?accept_repo=users/emaprlab/public

Then link to this GEE script to download source data.

You will need to fill out these variables in the inputs section.

var startYear = 1984;
var endYear = 2017;
var startDay = '06-20';
var endDay = '09-20';
var aoi = ee.FeatureCollection('users/emaprlab/timesync_legacy_demo/timesync_legacy_demo_aoi').first().geometry();
var description = 'timesync_legacy_demo'
var gDriveFolder = 'timesync_legacy_demo';
var crs = 'EPSG:5070';
var affine = [30.0, 0, 15.0, 0, -30.0, 15.0];

After you've defined the parameters, press the run button in the code editor, then activate the Task tab and you should see two tasks ready to run. One is for exporting the image stack and the other is for exporting the buffered AOI bounding box. Press the run the button for each task. You'll be prompted to confirm the export requests. Confirm the requests and wait for the tasks to finish.

3. Download TimeSync-Legacy Source Data from Google Drive

Once the export task has completed, go to the Google Drive associated with your GEE account. Find the folder that was defined as the gDriveFolder variable in the previous step. Download the folder or the contents. Depending on how large your AOI is, there may be only a single file or there many be serveral files that represent a series of spatial subsets of the AOI. Your downloaded files might be zipped, if so, unzip them and move the files to a 'prep' folder in a TimeSync project directory that might look like this:

C:\mock\timesync\project\
                 |
                 +-- images\
                 |
                 +-- prep\

The 'images' folder should be empty. The 'prep' folder should contain one or several .tif files and a single .geojson file.

4. Run TimeSync-Legacy Source Data Preparation Python Script

In this step you'll run the tsl_gee_stack_unpack.py script from the command prompt. It is recommend that you use the OSGeo4W Shell or Anaconada Prompt to run the script.

1. Open a text editor and write the command for executing tsl_gee_stack_unpack.py. The usage is:

tsl_gee_stack_unpacker.py [project prep dir] [project images dir] [filename prefix]

Here is a mock call:

python tsl_gee_stack_unpacker.py C:\mock\timesync\project\prep C:\mock\timesync\project\images timesync_legacy_demo

2. Open a command prompt and cd to the TimeSync-Legacy-Package directory where the tsl_gee_stack_unpacker.py script is located. Example:

C:
cd \mock\TimeSync-Legacy-Package

3. copy and paste the command you wrote in the text editor into the command prompt and hit enter.

4. The program will print its progress and will be outputting .bsq and sidecar .hdr files in the *\images directory.

5. Make TimeSync-Legacy Source Image Lists

In this step you'll create image list files for reflectance and tasselled cap image locations. A python script will automatically generate the lists. The script is tsl_image_list_maker.py it is located in the TimeSync-Legacy-Package directory. Run the file using a command prompt

1. Open a text editor and write the command for executing tsl_image_list_maker.py. The usage is:

tsl_image_list_maker.py [project images dir]

Here is a mock call:

python tsl_image_list_maker.py C:\mock\timesync\project\images

2. If your command prompt from the previous step is not still open, open a new one and cd to the TimeSync-Legacy-Package directory where the tsl_image_list_maker.py script is located. Example:

C:
cd \mock\TimeSync-Legacy-Package

3. copy and paste the command you wrote in the text editor into the command prompt and hit enter.

If the program executes successfully then there should be two text files in the project images directory:

• tc_list.txt
• refl_lst.txt

Each of them contains the list of images and some information about them. The paths to these two file lists will be used as input to cell in the Database so that TimeSync knows where images are located.

python tsl_image_list_maker.py D:\work\proj\timesync_legacy\images

6. Create TimeSync-Legacy Project Database

TimeSync-Legacy uses an MS Access database to store information about the image time series and user interpretations. There are two databases .mdb files included in the TimeSync-Legacy-Package directory:

• tsl_db_demo.mdb
• tsl_db_template.mdb

The tsl_db_demo.mdb database contains a few points that intersect with the data that can be downloaded from the Google Earth Engine TimeSync-Legacy source data download link in Step 1. The other is a blank template that you can make a copy of and place directly inside on the project folder. Name the template file and then open it. You'll see 6 tables. You need to edit information in the imageSettings and plots tables.

Double click the imageSettings table to open it. Here is where you'll define the paths to the image lists so that TimeSync-Legacy knows where you get the image data. There is a column for the tasseled cap image list (tc_list.txt) and one for the reflectance image list (refl_lst.txt). Edit these cells to point to the full direcory paths of the files you created in the previous step.

Next you need to define some points you are interested in viewing the image time series, interpreting change, and/or validation. Open the plots table and edit the fields. The coordinates need to be in the same projection as the image data. You should be able to copy/paste/import from Excel, CSV files, etc to make this easier.

Save the changes.

7. Load Project Database in TimeSync-Legacy

Now we'll open the TimeSync-Legacy program and load the database you just setup. Navigate to the TimeSync-Legacy-Package directory and open the tsl_v3.9.8.0 folder. In it you'll find and file called TimeSync.exe which will run TimeSync without installation. Double click to open it.

Once it is open, click File > Open and then navigate to and select the .mdb file you just setup in the previous step. It should load up the plots in left panel and default to loading the first plot's time series image chips and spectral profile.