Knowledge Base

How to extract point and area samples of MODIS data using AppEEARS

This step-by-step tutorial demonstrates how to access MODIS data using the Application for Extracting and Exploring Analysis Ready Samples (AppEEARS). AppEEARS allows users to obtain and display point and area data using spatial, temporal, and layer subsets. MODIS data from NSIDC that are accessible in AppEEARS include the complete time series of MOD10A1, MYD10A1, MOD10A2, and MYD10A2. Time series data are plotted on several graphs within the interface and can also be downloaded in .csv (point data) or GeoTiff and NetCDF (area data) formats.

Step 1: Access the AppEEARS interface, https://lpdaacsvc.cr.usgs.gov/appeears/. An Earthdata login in required.

Step 1 - SMAP AppEEARS

Step 2: Under the Extract dropdown, choose Point Sample.

Area samples can also be chosen but the steps and options are slightly different than what are outlined in this article.

Step 3: Choose Start a new request.

Users can also copy a previous request or upload a JSON file. Both options are beneficial to loading previous order details, such as lat/long coordinates, temporal coverage, and data layers.

MODIS AppEEARS Step 3

Step 4: Fill in the data submission details.

For this article, use the following details:

  1. Name your project: MODIS Test
  2. Start Date: 01-01-2016
  3. End Date: 04-18-2018
  4. Enter product: MOD10A1
  5. Add layers of interest: NDSI_Snow_Cover & Snow_Albedo_Daily_Tile. Click on + to add individual layers and to remove individual layers.
  6. Enter coordinates of points you wish to obtain data for. A .csv file can be loaded if the format matches what is described on the page. Or, use the Add a coordinate tool on the map to populate the coordinates field with where you click on the map. For this article, simply copy/paste the coordinates below:

Aspen, 39.1911, -106.8175

Boulder, 40.0150, -105.2705

Denver, 39.7392, -104.9903

Durango, 37.2753, -107.8801

Grand Junction, 39.0639, -108.5506

Fort Collins, 40.5853, -105.0844

La Junta, 37.9850, -103.5438

Steamboat Springs, 40.4850, -106.8317

  1. Click SubmitMODIS AppEEARS 4

Step 5: Under Explore, track the progress of a submission

An email confirmation will also be sent when the order is completed.

MODIS AppEEARs Step 5

Step 6: Explore the results:

  1. When completed, click on the contents button (highlighted above) to view results and compare layers.
  2. The Temporal Comparison tab displays data values from individual sites and data layers over time. Hint: The time scales can be adjusted in the Time Series graph. Also, hover over a point on the graph to view the value and date. MODIS AppEEARS 6b
  3. The Layer Comparison tab allows comparison of each data layer with a time series and scatter plot graph at individual sites.MODIS AppEEARS 6c
  4.  The Categorical Overview tab displays a box and whisker plot of all sites for individual layers for the entire time series. Hover over individual plots to view related data values. MODIS AppEEARS 6d

Step 7: Download all data results

Back in the Explore tab, click the Download all Contents of the request button. Deliverables include the following:

  • .csv file with all the data
  • .json file with order details
  • .txt file with a list of all science granules used in the order as well as links to the data at NSIDC
  • .xml file of related metadata

MODIS AppEEARSFor more detailed instructions of how to use AppEEARS, please visit https://lpdaacsvc.cr.usgs.gov/appeears/help

Last Updated April 2018

86,5 Bot