ossim-rpf: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/ossim-rpf - from package: ossim-core

You may install the required package with command apt-get install {package}

Error in other languages:
ossim-rpf: bevel nie gevind nie
ossim-rpf: comandă negăsită
ossim-rpf: comando não encontrado
ossim-rpf: commande introuvable
ossim-rpf: command not found
ossim-rpf: käsku ei ole
ossim-rpf: không tìm thấy lệnh
ossim-rpf: komanda nerasta
ossim-rpf: Kommando nicht gefunden.
ossim-rpf: kommandot finns inte
ossim-rpf: komut yok
ossim-rpf: nie znaleziono polecenia
ossim-rpf: níor aimsíodh an t-ordú
ossim-rpf: no se encontró la orden
ossim-rpf: no s'ha trobat l'ordre
ossim-rpf: opdracht niet gevonden
ossim-rpf: parancs nem található
ossim-rpf: perintah tidak ditemukan
ossim-rpf: príkaz nenájdený
ossim-rpf: příkaz nenalezen
ossim-rpf: команда не найдена
ossim-rpf: командата не е открита
ossim-rpf: 命令找不到
ossim-rpf: コマンドが見つかりません