This SRI document is based on research funded by a ARPA grant: "This work was supported in part by the Advanced Research Projects Agency under Contract F19628-

This SRI document is based on research funded by a ARPA grant: "This work was supported in part by the Advanced Research Projects Agency under Contract F19628-92-C-0071." Which implies that it was in development long before the date on the PDF. Earth mapping was a very hot field in the 1980s with most of it being funded by intelligence agencies and classified.