REST Resource: dataLayers

Resource: DataLayers

Information about the solar potential of a region. The actual data are contained in a number of GeoTIFF files covering the requested region, for which this message contains URLs: Each string in the DataLayers message contains a URL from which the corresponding GeoTIFF can be fetched. These URLs are valid for a few hours after they've been generated. Most of the GeoTIFF files are at a resolution of 0.1m/pixel, but the monthly flux file is at 0.5m/pixel, and the hourly shade files are at 1m/pixel. If a pixelSizeMeters value was specified in the GetDataLayersRequest, then the minimum resolution in the GeoTIFF files will be that value.

JSON representation 
{
  "imageryDate": {
    object (Date)
  },
  "imageryProcessedDate": {
    object (Date)
  },
  "dsmUrl": string,
  "rgbUrl": string,
  "maskUrl": string,
  "annualFluxUrl": string,
  "monthlyFluxUrl": string,
  "hourlyShadeUrls": [
    string
  ],
  "imageryQuality": enum (ImageryQuality)
}
Fields
imageryDate

object (Date)

When the source imagery (from which all the other data are derived) in this region was taken. It is necessarily somewhat approximate, as the images may have been taken over more than one day.
imageryProcessedDate

object (Date)

When processing was completed on this imagery.
dsmUrl

string

The URL for an image of the DSM (Digital Surface Model) of the region. Values are in meters above EGM96 geoid (i.e., sea level). Invalid locations (where we don't have data) are stored as -9999.
rgbUrl

string

The URL for an image of RGB data (aerial photo) of the region.
maskUrl

string

The URL for the building mask image: one bit per pixel saying whether that pixel is considered to be part of a rooftop or not.
annualFluxUrl

string

The URL for the annual flux map (annual sunlight on roofs) of the region. Values are kWh/kW/year. This is unmasked flux: flux is computed for every location, not just building rooftops. Invalid locations are stored as -9999: locations outside our coverage area will be invalid, and a few locations inside the coverage area, where we were unable to calculate flux, will also be invalid.
monthlyFluxUrl

string

The URL for the monthly flux map (sunlight on roofs, broken down by month) of the region. Values are kWh/kW/year. The GeoTIFF pointed to by this URL will contain twelve bands, corresponding to January...December, in order.
hourlyShadeUrls[]

string

Twelve URLs for hourly shade, corresponding to January...December, in order. Each GeoTIFF will contain 24 bands, corresponding to the 24 hours of the day. Each pixel is a 32 bit integer, corresponding to the (up to) 31 days of that month; a 1 bit means that the corresponding location is able to see the sun at that day, of that hour, of that month. Invalid locations are stored as -9999 (since this is negative, it has bit 31 set, and no valid value could have bit 31 set as that would correspond to the 32nd day of the month).

An example may be useful. If you want to know whether a point (at pixel location (x, y)) saw sun at 4pm on the 22nd of June you would:

  1. fetch the sixth URL in this list (corresponding to June).
  2. look up the 17th channel (corresponding to 4pm).
  3. read the 32-bit value at (x, y).
  4. read bit 21 of the value (corresponding to the 22nd of the month).
  5. if that bit is a 1, then that spot saw the sun at 4pm 22 June.

More formally: Given month (1-12), day (1...month max; February has 28 days) and hour (0-23), the shade/sun for that month/day/hour at a position (x, y) is the bit

(hourly_shade[month - 1])(x, y)[hour] & (1 << (day - 1))

where (x, y) is spatial indexing, [month - 1] refers to fetching the month - 1st URL (indexing from zero), [hour] is indexing into the channels, and a final non-zero result means "sunny". There are no leap days, and DST doesn't exist (all days are 24 hours long; noon is always "standard time" noon).
imageryQuality

enum (ImageryQuality)

The quality of the result's imagery.

Date

Represents a whole or partial calendar date, such as a birthday. The time of day and time zone are either specified elsewhere or are insignificant. The date is relative to the Gregorian Calendar. This can represent one of the following:

  • A full date, with non-zero year, month, and day values.
  • A month and day, with a zero year (for example, an anniversary).
  • A year on its own, with a zero month and a zero day.
  • A year and month, with a zero day (for example, a credit card expiration date).

Related types:

JSON representation 
{
  "year": integer,
  "month": integer,
  "day": integer
}
Fields
year

integer

Year of the date. Must be from 1 to 9999, or 0 to specify a date without a year.
month

integer

Month of a year. Must be from 1 to 12, or 0 to specify a year without a month and day.
day

integer

Day of a month. Must be from 1 to 31 and valid for the year and month, or 0 to specify a year by itself or a year and month where the day isn't significant.

ImageryQuality

The quality of the imagery used to compute some API result.

Note: Regardless of imagery quality level, DSM outputs always have a resolution of 0.1 m/pixel, monthly flux outputs always have a resolution of 0.5 m/pixel, and hourly shade outputs always have a resolution of 1 m/pixel.

Enums
IMAGERY_QUALITY_UNSPECIFIED No quality is known.
HIGH Solar data is derived from aerial imagery captured at low-altitude and processed at 0.1 m/pixel.
MEDIUM Solar data is derived from enhanced aerial imagery captured at high-altitude and processed at 0.25 m/pixel.
LOW Solar data is derived from enhanced satellite imagery processed at 0.25 m/pixel.

Methods

get

 Gets solar information for a region surrounding a location.