Updates from Brent and Ross following discussion at meeting.

### Map Projections

- Data are provided in a simple cylindrical (equirectangular) map projection.

- Data are orthorectified to a sphere using the IAU radius => 1737.4km (sphere)

- Data are orthorectified to a sphere using the IAU radius => 1737.4km ([Archinal, et al. 2018](https://doi.org/10.1007/s10569-017-9805-5))

- Data are made available in 0 – 360 positive East coordinate system with a center longitude of 180 degrees using planetocentric latitude. 

- For observational data, pixel scale or resolution should be maintained at native scale, (i.e., do not up sample or down sample data.) 

- For derived data (e.g., DTMs), data should be made available at a reasonable resolution that avoids extrapolation of information.

- For observational data, pixel scale or resolution should be maintained at native scale or better, (i.e., do not average data.) 

- For derived data (e.g., DTMs), data should be made available at a reasonable resolution that avoids interpolation of information.

- Data for polar areas (latitudes > 65˚ North or South) should use a polar stereographic projection centered at the pole.

### Vector Symbology

**DRAFT**

### Formats for Offline Data Access

- Data in raster format will be provided as [cloud optimized GeoTiffs](https://www.cogeo.org)(COG), complying with the above projection standards. 

- Data in raster format will be provided as [cloud optimized GeoTiffs](https://www.cogeo.org)(COG), complying with the [cartographic standards]({{< ref "cartographic_standards" >}}). 

- Data in vector format will be provided in [OGC GeoPackage format](https://www.geopackage.org) with information stored in decimal degrees (i.e., no map projection applied)

### Formats for Online Data Access

- Data in raster format can be provided as [cloud optimized GeoTiffs](https://www.cogeo.org), complying with the above projection standards. These data will be accessed via their [STAC](https://www.google.com/search?client=safari&rls=en&q=spatio-temporal+asset+catalog&ie=UTF-8&oe=UTF-8) data files.

- Data in raster format can be provided using OGC compliant WMS service. Said service must encode a proper IAU 2015 projection code.

- Data in vector format can be served using an OCG compliant WFS or WMTS service using the standards defined above. The server must encode a proper IAU 2015 projection code.

- The STAC-API specification (a remotely accessible search service) will be used to support metadata query and data discoverability. 

- Data in raster format can be provided using an OGC compliant [WMS](https://www.ogc.org/standards/wms) service. This service must encode a proper [IAU 2015/2018 projection code](https://ui.adsabs.harvard.edu/abs/2021LPICo2549.7012H).

- Data in vector format can be served using an OCG compliant [WFS](https://www.ogc.org/standards/wfs) or [WMTS](https://www.ogc.org/standards/wmts) service using the standards defined above. The server must encode a proper IAU 2015/2018 projection code.

- The [STAC](https://stacspec.org)-API specification (a remotely accessible search service) will be used to support metadata query and data discoverability. 

**DRAFT**

### Body Parameters

The Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015 (2018) and the [Final Report of the Lunar Critical Data Products Specific Action Team](https://www.lpi.usra.edu/mapsit/standup-committees/LCDP-SAT-REPORT-20211110.pdf) (LCDP-SAT) body parameters will be used. This includes a sphere radius of 1737.4km, the 2008 JPL DE 421 ephemeris rotated to the mean Earth/polar axis (ME) system and rotation parameters as defined in Table 2 (Archinal, et al., 2018).

The [Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015 (Archinal, et al. 2018)](https://doi.org/10.1007/s10569-017-9805-5) and the [Final Report of the Lunar Critical Data Products Specific Action Team](https://www.lpi.usra.edu/mapsit/standup-committees/LCDP-SAT-REPORT-20211110.pdf) (LCDP-SAT) body parameters will be used. This includes a sphere radius of 1737.4km, the 2008 JPL DE 421 ephemeris (but soon expected to change to the DE 440 ephemeris) rotated to the mean Earth/polar axis (ME) system and rotation parameters as defined in Table 2 (Archinal, et al., 2018).

### Horizontal and Vertical Datum

Reference sphere defined as 1737.4km as defined by the IAU (IAU;2018). Proxy products usable to tie to the vertical reference frame (and have topography or shape) include:

- Gridded Lunar Orbiter Laser Altimeter (LOLA) 

Reference sphere defined as 1737.4km as defined by the IAU ([Archinal, et al. 2018](https://doi.org/10.1007/s10569-017-9805-5)). Proxy products usable to tie to the vertical reference frame (and have topography or shape) include:

- [Gridded Lunar Orbiter Laser Altimeter (LOLA)](https://doi.org/10.17189/1520642)

- SLDEM 2015

- Lunar Polar Gridded Data Record

The horizontal datum to be used is the 2008 JPL DE 421, which, as per the LCDP-SAT, is only slightly different than the 2021 JPL DE 440 ephemerides. The proxy products that data creators can use to tie new data products to the horizontal reference frames include:

The standard horizontal datum to be used is the 2008 JPL DE 421, which is expected to shift to the 2021 JPL DE 440 ephemeris (and new projects should begin using the DE 440). The proxy products that data creators can use to tie new data products to the horizontal reference frames include:

- Gridded Lunar Orbiter Laser Altimeter (LOLA) 

- SLDEM 2015

- Lunar Polar Gridded Data Record

At this time, no global visible observations are usable to rigorously align to the horizontal reference frame.

### Map Projections