PROJECT NAME
  MRElMaarry_HellasBasin4

HIRISE SOURCE IMAGES
 ESP_025437_1410
 ESP_025147_1410

TECHNICAL CONTACT INFORMATION
  NAME          MOHAMED RAMY EL MAARRY
 INSTITUTION   USGS-ASTROGEOLOGY

Products are tied to MOLA elevations.
Elevation range for this project:
  VALID_MINIMUM    = -7403.16 m
  VALID_MAXIMUM    = -6303.16 m

SOCET SET NGATE was used to extract terrain.

Post spacing in DTM is 1 m.

NOTE: 

NAMING CONVENTION:

DTM PRODUCT_ID = aabcd_xxxxxx_xxxx_yyyyyy_yyyy_Vnn

	where

		aa = DT, indicating it's a DTM product

		b = type of data

			E = areoid elevation

			R = radii

		c = projection (others are possible but these are the important ones)

			E = Equirectangular

			P = Polar Stereographic

		d = grid spacing

			A = 0.25 m

			B = 0.5 m

			C = 1.0 m

			D = 2.0 m

			etc.

		xxxxxx_xxxx = orbit number and target code from SOURCE_PRODUCT_ID[1]

		yyyyyy_yyyy = orbit number and target code from SOURCE_PRODUCT_ID[2]

		V = letter indicating producing institution

			U = USGS

			A = University of Arizona

			C = CalTech

			N = NASA Ames

			J = JPL

			O = Ohio State University

		    P = Planetary Science Institute

			Z = Other

		nn = 2 digit version number



ORTHOIMAGE PRODUCT_ID = XSP_xxxxxx_xxxx_CCC_S_NN_ORTHO

	where

		XSP_xxxxxx_xxxx = HiRISE source observation ID 

		                  (mission phase_orbit number_target code)

		CCC = color content

			RED = visible RED, 1 band image

			IRB = 3 band enhanced color (IR, RED, BG)

		S = grid spacing (comparable to the DTM naming convention above)

			A = 0.25 m

			B = 0.5 m

			C = 1.0 m

			D = 2.0 m

			etc.

		NN = a sequence number to distinguish between orthorectified 

		     images from the same HiRISE observation that may be 

		     created from different DTMs.

		ORTHO indicates that the image has been orthorectified



KNOWN ARTIFACTS

 These are known artifacts present in some, but not all, HiRISE DTMs.

 They may not be present in this DTM! Look at the terrain shaded relief 

 to detect these before using the DTM!

 - Boxes

	Some DTMs have square areas that are usually about .5-1 m different 

	in elevation from the surrounding areas. These are artifacts of the 

	processing algorithms used in Socet Set ((c) BAE Systems). There may 

	be goups of these boxes. They are almost impossible to edit, so the 

	user should look for such artifacts in a terrain shaded relief map 

	before using the DTM for analysis.

 - CCD seams

	A HiRISE image is made up of 10 individual images, stitched together 

	along their long edges.	In a DTM, these seams can be visible as long 

	lines. These seams are difficult to remove.

 - Faceted areas

 	Areas that were very bland (low contrast) or deeply shadowed with 

 	low contrast and low signal may have a "faceted" look to them. 

 	Terrain in these areas is not trustworthy.