Data Access Viewer (DAV)¶
Introduction¶
The POWER Data Access Viewer (DAV) provides geospatially-enabled solar and meteorological parameters formulated for assessing and designing energy systems, building systems and infrastructure, and agricultural management. The POWER DAV is a responsive desktop application that runs on all platforms (Apple, Android, and Windows) and modern web browsers (Chrome, Safari, Edge, Firefox, etc.). Through the DAV, POWER provides downloadable data that can be integrated into custom software and applications for further processing, analysis, and visualization.
The POWER DAV leverages the ArcGIS SDK for JavaScript and is built with an Esri Calcite interface. POWER developers designed this application for all users, regardless of previous experience with NASA data or technical expertise, to access Earth data and create custom plotting graphs for interacting with geospatial data, subsetting, geoprocessing, and analysis.
Tools and Features¶
The following sections detail the layout and functionality of the POWER DAV, which enables you to locate, analyze, and interact with geographic data and map features.
- Core DAV Tools are used to download and interact with POWER data.
- Map Viewer Widgets enable interactive map functionality.
- Application Version Number provides a snapshot in time and functionality.
- Location Search Bar allows you to find addresses or places on the map.
- App Settings allows you to personalize the DAV, choosing between light/dark mode and imperial/metric units.
- Comparative Analysis Tool is used to visualize POWER data as layers in the map.
- Validate allows you to validate POWER data against ground measurements.
- Parameter Dictionary allows you to explore and access a wide range of POWER parameters.
- Documentation easy access to data documentation, frequently asked questions, and tutorials.
Core DAV Tools¶
The core DAV tools offer a range of functions for analyzing, measuring, and interacting with POWER data and maps. The map viewer widget panel will display full screen depending on the size of the device. You can minimize the panel while interacting with the map viewer, rather than close the widget completely.
| Tool | Description |
|---|---|
| Single Point | The 'Single Point' tool provides access to near real-time data sets and plotting for a single coordinate (lat/lon). |
| Regional | The 'Regional' tool provides access to near real-time data sets by region up to 10 x 10 degrees (lat/lon). |
| Global | The 'Global' tool provides access to global climate temperature and temperature/moisture zones. |
| Visualize | The 'Visualize' tab contains a comprehensive list of monthly and annual data parameter map layers. |
| Graphing | The 'Graphing' tool provides various additional graphing capabilities for a single coordinate (lat/lon). |
| Reports | The 'Reports' tool provides the ability to generate custom climatological reports and data for a single coordinate (lat/lon). |
| Insights | The 'Insights' tool returns area-weighted summary statistics and derived climate indicators over a geographic region. |
| RASI | The 'RASI' projection tool provides downscaled future climate projection data under various scenarios. |
| Validate | The 'Validate' tool compares POWER data to NOAA ISD/GSOD, BSRN, and AERONET surface observations for descriptive, comparative analysis for data validation. |
| Parameters | The "Parameters" tool details all parameter metadata in the app to make selecting the right data easier. |
High-Resolution Toggle¶
The data resolution toggle is available when making a single point data request. When high resolution is enabled, the DAV substitutes higher resolution NASA sources for any requested parameter that has a high resolution counterpart:
| Domain | High-Resolution Source | Native Resolution |
|---|---|---|
| Precipitation | IMERG | 0.1° (~10 km), daily UTC |
| Soil Properties | SMAP | ~9 km |
| Cloud Properties | GCC | 3 km, hourly |
| Meteorology | HydroSCS | Sub-degree |
| Energy Fluxes | HydroSCS | Sub-degree |
Parameters that do not have a high resolution equivalent continue to be served from the primary MERRA-2 and CERES archive even when the toggle is on. The same toggle is available in the API via the parameter aliases listed in the Parameter Dictionary. For background on each high resolution source, see the High-Resolution Sources methodology.
Map Viewer Widgets¶
The map viewer widgets are interface tools used for viewing and interacting with maps and map layers. You can select from various basemaps, zoom in and out of the map, search by entering coordinates or an address, and locate your position on the map.
| Image | Description |
|---|---|
 | The 'Zoom In' button enlargers the map for an area of interest. |
 | The 'Zoom Out' decreases the map's zoom level, allowing you to view a larger geographic area with less detail. |
 | The 'Default Extent' widget resets the map view to its original extent. |
 | The 'My Location' widget allows the application to detect your IP location and zooms the map to that area. Accuracy may vary depending on your network and device. |
 | The 'Basemap' widget allows the application to toggle between various Esri basemaps. |
Application Version Number¶
The application version number changes over time as updates modify the functionality and interface of the Data Access Viewer. Each version update does not address all known bugs or improvements. Therefore, knowing the version number is useful for three reasons: citing the POWER DAV as the service providing data, communicating with the POWER team to identify bugs or suggest improvements, and working with others to identify available functionality.
For more information about citing POWER, please refer to our referencing guide.
Comparative Analysis Tool¶
The comparative analysis tool allows you to add multiple map layers from the "Visualize" tab. You can drag and drop as many parameters as you like from the "Visualize" tab to the comparative analysis queue. Within the queue tab, you can choose layers to visualize and compare in the map using Esri's swipe feature.
Resources and Acknowledgements¶
These additional features credit the project lead, outline privacy policies, and offer assistance in the form of documentation and tutorials.
POWER Map Layers¶
The 'Visualize' tool provides the ability to visualize global POWER parameters on a gridded map. Currently, monthly and annual data are available.
Visualize - Data Access Steps
1) Find the parameter, temporal level of interest, and grid (optional) in one of the dropdowns in the "Visualize" tool.
2) Use the 'Adjust Transparency' slider to the right of the selected parameter (under the two box icon) to adjust the parameter layer opacity.
3) Filter with the 'Adjust min and max display values' slider next to the right of the selected parameter (under the slider icon).
4) Add to comparative analysis queue with the widget on the right. Then view the layer in the queue to the right of the map.
5) With multiple layers in comparative analysis, compare them on the left and right with the swipe tool (under the split square icon with two arrows).
6) Select a point on the map for data set values by location.
Reports Data Access¶
The 'POWER Reports Data Access' widget provides access to reports from 2001 through the most recent full year by a coordinate in a similar fashion to the 'POWER Single Point Data Access' widget.
Reports - Data Access Steps
1) Choose a Report Type: You can select to view a report on either climatic design conditions, windrose, or psychrometric analysis.
2) Enter Coordinates or Add Location to Map: Enter global coordinates in decimal degrees or select a point on the map to retrieve coordinates at the selected location. You can also clear the selected point off the map with the x button in the map pane.
3) Select Time Extent: You can select a start and end year from 2001 through the most recent full year.
4) Submit and Process: Once you have selected all data options, you can submit and retrieve the requested report as either an HTML or XLSX file.
Limited Parameter Selection¶
The Data Access Viewer enables the most widely-applicable data parameters and parameter collections for ease of use. Other parameters, like Reservoir Height from GWM, are only available in the DAV if a relevant user community is selected. However, the POWER API enables the complete parameter list, no matter the community.
Reservoir Height is only available in the Data Access Viewer for the renewable energy community, as GWM curated this data parameter for hydro-electric use cases.